Cooler end to the month

Sydney and Jyväskylä experienced a slightly cooler finish to the month compared to previous weeks.

In Sydney a week long run of days above 25C came to an end on Thursday. The 7 days prior were quite consistent with daily maximums between 25.1C and 26.5C. The 26.5C recorded on both May 22 and 23 was the monthly high.

Thursday May 29 saw a top of only 20.0C and yesterday didn't climb above 20C at the Airport, reaching only 19.1C. This was the first day with a maximum below 20C in 3 weeks.

Minimums, however, have remained high compared to earlier this month. The second half of May has had an average minimum 2C higher than the first half. Tuesday May 27 saw the highest daily minimum of the month with 16.3C. This is the highest May minimum in the last 6 years.

A few coastal showers arrived this morning just after midnight. The Airport has recorded 2.4mm today. This was the first rainfall since May 13. More rain is forecast tomorrow, but temperatures should remain just above 20C for the coming week.

As I mentioned in my previous post, Jyväskylä's change to cooler weather happened already earlier this week. The forecast on Monday predicted no days above 15C until today. It was almost right too, but yesterday managed to reach 16.8C.

The coldest day this week was Tuesday. It had a maximum of only 8.4C. This was a drop of more than 20C from 3 days earlier. It was also the lowest maximum in just under 3 weeks. Tuesday also saw the lowest minimum of the week with 2.5C.

Rain accompanied the cool change as well. After storm activity on Sunday and Monday, Tuesday to Friday saw larger but less intense areas of rain spread across the country. Jyväskylä received 14.4mm in that period, 11.0mm of that falling on Thursday.

Cool change for Finland after a week of warm summer weather

'Hot' and 'Finland' aren't two words you often see connected to each other, but the past week has seen some very warm temperatures in the southern half of the country. An Australian like myself might consider the recent weather to be pretty much perfect, but a Finn would certainly say it has been hot. The warm period has come to an end today though as cold north easterly winds lead to a brief return of jackets and long pants.

From May 18, Jyväskylä endured a run of 8 consecutive days above 20C. 5 of those, including the last 4, also climbed above 25C. Of the past 6 years, only 2010 had a greater number of consecutive May days above 20C with 9 between May 13 and 21. 2010 also saw 5 May days above 25C.

From Thursday May 22 Jyväskylä Airport saw daily maximums of 26.8C, 28.1C, 29.3C and 26.8C. Saturday's 29.3C equalled the monthly high from May 19. Daily minimums during the past week have also been above average. The 6 days from May 20 all had daily values above 10C. May 20's 14.4C was the top and is the third highest May minimum in the last 6 years.

Jyväsjärvi in the late afternoon of May 24

A change in the weather appeared already yesterday morning. Intense isolated storms moved east across the country from around 6am until late last night. Jyväskylä centre had a brief shower around 7am. Storm activity threatened the city throughout the day as dark clouds built in the west and rolled east. The main city area of Jyväskylä managed to escape heavy rain that was experienced elsewhere, but lightning and thunder weren't too far away.

Flowers bask in the sunlight while storm clouds build north of Jyväskylä on May 25

Part of the storm system that dumped 21mm of rain in
one hour at Tikkakoski in the evening of May 25

Two storm cells moved east just north of Jyväskylä during the day, one around 1pm, the other just after 6pm. Tikkakoski, the site of Jyväskylä's weather station 25km north of the city, saw very heavy falls, especially between 6pm and 7pm. A total of 21mm fell during that hour. For comparison, April saw a monthly total of only 25mm. Further storms hit the Airport in the early hours of today also. Another 24mm was recorded between midnight and 4am. Somehow the city escaped most of this rain too. 

Temperatures dropped dramatically with the arrival of the evening storm. Just after 6pm it dropped from more than 26C to 15C in only 20 minutes. Temperatures continued to decline during the morning, from around 15C at midnight to below 10C by 1pm, down to 8.5C by 5pm. A high pressure system currently sitting in the Norwegian Sea is now pushing cold air from the Arctic across most of the Nordic region. 

Current forecasts for the coming 5 days show nothing higher than the 15C on Saturday. Rain is expected tonight along with the chance of wet snow with temperatures possibly dropping to as low as 2C. A top of 10C is predicted for tomorrow and Wednesday, with rain on Thursday and Friday. 

After the past week it's amazing to think how quickly the weather can change.

Sydney on track for warmest May on record

It's kind of hard to believe given Sydney's cool start to May this year, but with recent temperatures both weather stations at the Airport and Observatory Hill are on track to register their warmest May average maximums on record.

Including yesterday which got to 26.5C, the prior 2 weeks have had an average daily maximum of 24.0C at the Airport. Similarly, Observatory Hill has seen an average of 24.4C for the same period. Not even the long term average for April is that warm. The long term average at the Airport between May 10 and 23 is 19.8C. The 2 week autumn period with a long term average maximum of 24.0C can be found between March 28 and April 10.

The current average monthly maximum at Sydney Airport after 23 days of the month stands at 22.3C. Since records began in 1939, the warmest average maximum for May of 22.8C was recorded in 1958. The next highest of 22.7C was just recently in 2007.

For Observatory Hill the current average monthly maximum is 23.0C. Records there date back to 1859, but 1958 also holds the record with 22.7C. 2007 is again the second warmest with 22.4C.

Based on current Bureau of Meteorology forecasts up until May 31, Observatory Hill will easily beat the 1958 record with the Airport either equalling or just beating it.

Unlike the average maximums, the minimums for the month so far, while above average, look unlikely to challenge the all time records. 1989 holds the record for both locations with 13.3C at the Airport and 14.0C at Observatory Hill, easily above the current respective figures of 12.3C and 12.4C.

Stormy weather yesterday evening in Finland

One of the warmest May days on record was experienced yesterday in Finland. However, storms cooled things down in locations throughout the country, especially in Western Finland, from the afternoon until the early hours of today.

The highest temperature in Finland yesterday was recorded in Heinola. It ended up peaking at 30.8C there, only 0.2C off the all time Finnish record of 31.0C measured at Lapinjärvi on May 30 and 31 in 1995. It was only the second day with temperatures above 25C this year and that measurement is already warmer than any day anywhere in Finland throughout 2008 and 2009.

Jyväskylä reached a top of 29.3C. Other notable recordings were 30.7C in Lappeenranta and 30.5C in Kouvola. While the all time record for Finland wasn't broken, many locations broke individual May records.

Unsettled air in the Baltic Sea led to increasing storm activity during the afternoon. Turku was already hit around 1pm as storm cells developed and moved north. Jyväskylä escaped the worst of the storms, but did see some lightning strikes in the evening. A small amount of rain, 2.0mm, was also recorded at Jyväskylä Airport. Viitasaari and Pihtipudas, both north of Jyväskylä, received around 20mm each.

Storm clouds to the west of Jyväskylä just before 8:30pm on May 19

The long term monthly average for May of 8,500 ground strikes was overhauled in just one day. The Finnish Meteorological Institute reported a total of over 13,000 ground strikes yesterday. As seen in the article linked, the worst affected areas were to the west and north of Jyväskylä.

Cool start to May makes way for warm weather

Summer weather has arrived at last in Finland. Yesterday was the first official 'hellepäivä' as temperatures climbed above 25C in locations in southern Finland for the first time this year. A high pressure system is sitting east of the Finnish-Russian border and is generating warm south easterly winds across most of the country.

The highest temperature yesterday was recorded in both Turku and Heinola. It reached 25.7C in each city. Other locations to reach 25C included Hämeenlinna, Kokemäki, Kouvola and Lahti.

In Jyväskylä it hovered around 23C for a few hours in the afternoon, peaking at 23.6C. It was the first day above 20C since September 14 last year, ending a run of 243 consecutive days below that mark. The table below shows that this is actually the lowest such figure of the past 5 winter periods.

Last and first days above 20C and the number of consecutive days below 20C for the past 5 winter periods

The warm weekend in Jyväskylä was quite a change from Friday when it only reached 9.1C. It was 10C warmer on Saturday getting to 19.1C.

Today has been even warmer than yesterday with temperatures climbing above 25C in locations from Helsinki all the way up north to Oulu. Jyväskylä has reached around 29C, the first 25C+ temperature since August 8 last year. The all time record for May in Finland was close to being broken in Heinola. It got to 30.4C there, just off the record of 31.0C.

On the grounds of the University of Jyväskylä on May 18

Small plane over Jyväskylä on May 18

Sydney has also been enjoying some warm weather. The temperature reached 26.2C at the Airport this afternoon, the warmest in almost 3 weeks. Friday to Sunday saw tops of 25.4C, 25.7C and 24.2C. This heat is rather unusual for this time of year and it looks like it will continue, possibly all the way into early next week.

Minimums have also been higher than normal, hovering between 11.7C and 13.4C for the past 6 days. One observation worth pointing out is that it still hasn't dropped below 10C at the Airport yet this year. The past 5 years had all seen at least one minimum below 10C by May 15 and looking at Bureau of Meteorology records, this is the latest date since 2007, when it first dropped below 10C on May 23.

In fact, since temperature records began at the Airport in 1939, there have only been 4 years in which it hadn't dropped below 10C by May 19. Other than 2007, 2003 first saw a temperature below 10C on May 29, it was May 23 for 1989 and May 21 for 1974. The current weekly forecast for Sydney doesn't show any minimums below 13C, so breaking the 2003 record is definitely possible.

Warm change for Sydney, rain for Finland but warm weather on the way

Despite a cooler than normal start to May, Sydney has seen some warmer temperatures during the last few days. Finland, on the other hand, has seen cool weather continue this week. The highest daily rainfall totals of the year so far were also recorded in Jyväskylä and locations in Eastern Finland.

The last 7 days at Sydney Airport have all had a daily maximum above 20C. May 10's 24.4C is still the highest of the month but light northerly winds and temperatures in the low 20s have made the last few days fairly pleasant.

There were a few showers in coastal suburbs from late Monday to the early hours of Tuesday. The Airport received 8.4mm between 11pm and 4:30am. Observatory Hill got a little bit more with 11.2mm between 8:30pm and 4am. The 7.0mm total at the Airport for Tuesday was the highest daily total since April 15.

Warm temperatures for this time of year in the low to mid-20s are forecast to continue for the next week. It should also be dry and sunny.

May 10 also remains as Jyväskylä's warmest day of May so far. It reached 12.5C then. In comparison, the 5 previous years from 2009 to 2013 had seen much warmer maximums by the 15th day of the month. May 2009's highest temperature at May 15 was 20.0C. It was 27.4C in 2010, 22.4C in 2011, 16.4C in 2012 and 19.5C in 2013.

Tuesday evening and the early hours of Wednesday saw heavy falls throughout most of Finland's east. Some locations recorded more than 60mm. Mikkeli recorded the highest total across the evening of May 13 and morning of May 14 with 63.4mm. Varkaus got 62.9mm while Sulkava, west of Savonlinna, received 56.4mm.

Jyväskylä also recorded good falls. A total 13.3mm fell on the 13th with an additional 12.8mm coming on the 14th. The last 7 days have seen rain recorded at Jyväskylä Airport. This is the longest streak of the year so far and the monthly total now stands at 55.7mm, easily above any other monthly total of the year to date. After a rather dry March and April, rain has helped the landscape turn green a little more quickly despite the unusually low temperatures.

The coming week looks promising though for those hoping for warmer weather. Saturday is forecast to shoot above 15C for the first time in 2 and a half weeks before it goes above 20C on Sunday for the first time since last September. Early next week will be very different compared to the past couple of weeks. Tuesday is currently forecast to reach 29C.

Cold start to May

Both Sydney and Jyväskylä have experienced one of the coldest starts to May in recent years. Up until today, this is the coldest start to May in at least the last 6 years for Jyväskylä while Sydney is experiencing its second coldest start.

This weekend has seen some slightly warmer temperatures in both cities compared to the previous week, but the first 9 days were unusually low compared to the average. Sydney Airport hit a top of 24.4C yesterday. That was the highest in a week and a half. Jyväskylä also had its warmest temperature since late April with 12.5C yesterday.

The graphs below highlight the cold weather that has been seen recently. The lines show the progressive averages throughout the month of May since 2009. Sydney graphs also show the long term average.

Progressive average minimum for May at Sydney Airport in the period 2009-2014 plus the long term average

The average low for the month dipped to the lowest of the period in the 6 days of May 5 to May 10. However, the 14.4C minimum from today has helped it climb above 2011's value. 2014's figure is also below the long term average.

Progressive average maximum for May at Sydney Airport in the period 2009-2014 plus the long term average

2014's figure for the average maximum at the Airport has remained fairly consistent as the second lowest at this point in the month. It is also well below the long term average.

Progressive average minimum for May at Jyväskylä Airport in the period 2009-2014

In Jyväskylä, temperatures for May have been well below those of the previous 5 years. There have been 4 days with minimums below -5C, something that didn't occur once in all previous 5 editions of May.

Progressive average maximum for May at Jyväskylä Airport in the period 2009-2014

The graph above excludes the maximum for today. The average maximum for the month so far is also the lowest of the past 6 years. 2010, the second lowest line at this date, experienced unusually high temperatures (25C+) in the middle of May helping its average to climb as the month wore on. The current forecast for the coming week doesn't show temperatures anywhere close to that.

April 2014 Review - Jyväskylä

Once again Jyväskylä recorded an above average month in terms of temperature in April 2014. The Finnish Meteorological Institute's average for the month was 3.7C, compared to my recording of 3.3C. The 3.7C figure makes it the equal fifth warmest April since at least 1961. In the 16 years since 1998, only 3 Aprils have been below the 1981-2010 average. It was a rather dry month also with below average rainfall and plenty of sun.

April averages at Jyväskylä Airport for the period 2009-2014

The average maximum for April 2014 was almost as warm as that in 2011, but the average minimum was the third lowest since 2009. In the south, Helsinki recorded its fourth warmest April on record with an average of 5.9C. It wasn't quite as warm in the north, but Sodankylä still recorded a slightly above average reading.

Not one of the four extremes for April this year was the most extreme since 2009. The highest temperature of 17.3C came on April 26. This was one of 3 days above 17C, but still a few degrees off the 20.2C figure from 2011. The highest minimum of 4.2C came a few days earlier on the 21st. The lowest temperature of the month was recorded on the 10th, a chilly -10.3C, and April 1 was responsible for the coldest day when it only got as high as 2.0C.

April 4 saw the lowest temperature of the month in Finland when it dropped to -24.0C at Salla. Kemiönsaari, in the south west, recorded the month's highest temperature, 20.4C on the 21st.

As mentioned above, even though the average maximum was quite high, the average minimum was also quite low. The average difference between the daily minimum and maximum was 11.7C. This was the highest of the past 6 years. That meant cooler overnight temperatures, but warmer daytime temperatures. The graph below shows the number of days where the minimum was below 0C and also the number of days where the maximum climbed above 10C. 2014 has the second highest and highest respective values.

Number of April days in Jyväskylä with a minimum below 0C and a maximum above 10C

According to FMI, a total of 21mm fell at Jyväskylä Airport during the month. My total read 25.2mm. Either way, both are quite far below the 1981-2010 average of 35mm. In fact, most of Finland recorded below average totals. Only in the far north was the average met or exceeded.

Most of the rain for Jyväskylä fell across the 3 days of April 11, 13 and 14 when 7.0mm, 7.6mm and 7.5mm was respectively recorded. The month had 9 days on which rain was recorded and the longest streak without rain was the 9 days between the 19th and 27th.

This post is my 100th post on this blog. For the few people who read this, thanks!

Spring snow for Finland during the weekend, chilly temperatures and rain in Sydney

People throughout Finland were already wondering what happened to spring thanks to the low temperatures during last week, but the questioning grew during the weekend when snow fell on both Saturday and Sunday.

Rain, wet snow and snow affected most of the country. Snow was seen as far south as Helsinki and the precipitation radar was rather spotty as a result of isolated, and sometimes heavy, falls. In Jyväskylä there were a couple of brief periods when the ground turned white. Kivijärvi, 100km to the north, saw several centimetres. Driving conditions were especially dangerous in some areas due to the fact that most locals had already changed to summer tyres last month.

In Jyväskylä, May 1 was responsible for the coldest May temperature since at least 2009 when it dropped to -5.9C, but yesterday ended up being the coldest May day in that period. It only briefly popped above 5C in the afternoon, reaching a high of 5.2C. This was 1.5C lower than May 1's 6.7C, which had been the third coldest in the 6 year period. Yesterday's temperature beat the 5.9C recorded on May 8 in 2010 and the 5.8C from May 3 in 2011.

Sydney also saw unusually cold temperatures during the weekend. Saturday was especially cold. It only reached 15.9C at the Airport, a maximum not typically seen for another few weeks. To highlight how unusual this is, the table below shows the first dates with a maximum of 15.9C or lower since 2009.

First date for a daily maximum of 15.9C or below for the period 2009-2014

Including today, it still hasn't dropped below 10C yet this year at the Airport, but it came mighty close when it was 10.1C this morning. This isn't as unusual as the statistic above. Only 2009 and 2012 had recorded a temperature below 10C by this time of the year.

Showers accompanied the cooler temperatures also. The totals weren't that high, but 1.4mm fell on May 3 and 4.4mm on May 4. The rain also fell early in the morning and Sunday turned out to be a fairly clear day.

A couple of the past 6 years have still seen a day or two above 25C beyond this date, but going on current forecasts, it doesn't look like that will be happening this year. Potential showers and daily maximums between 19C and 22C are predicted for the next week.

April 2014 Review - Sydney

Sydney experienced a slightly warmer than normal April in 2014. The average minimum was the highest for several years while the average maximum was also among the highest in the past few years. Rainfall was below average at the Airport despite more than half of the days of the month recording rain.

The graph below shows the April averages at Sydney Airport during the last 6 years. The long term average is on the left.

April averages at Sydney Airport for the period 2009-2014 plus the long term average

The average minimum of 15.8C (Bureau of Meteorology recorded 16.0C) was the highest average April minimum since 2005. Only 3 days had a maximum below 20C. This helped keep the average maximum up despite there being only 8 days above 25C. For comparison, April 2011 had 14 days above 25C, but still had the same average.

The highest temperature of the month was recorded quite late; it hit 30.1C on April 24. That was only the 4th April day to hit 30C in the past 8 years, and it was the equal second highest in that period. The highest minimum of 19.6C came on the 3rd. The lowest monthly temperature of 12.3C on April 20 was the highest such figure since 2007. Finally, both April 14 and 27 recorded the lowest daily maximum of 19.1C. This was the second highest such figure since 2009.

The number of calendar days with rain for April was quite high. There was a total of 17 days on which rain was recorded. This is compared to the long term average of 11. Despite that, the total monthly rainfall of 72.6mm was far below the average of 106.9mm.

Daily rainfall totals during April 2014

April 6 was responsible for the greatest daily total with 19.6mm. As shown in the graph above over 15mm was recorded on April 15 also. Coastal falls were much greater than elsewhere in Sydney. Observatory Hill received a much greater amount of rain than many other locations. The monthly total there was 121.0mm, just below the average of 127.2mm. Western Sydney received even lower totals than the Airport. Only 49.0mm was recorded at Canterbury and Sydney Olympic Park only got 38.2mm.

The average of the strongest daily gusts for April of 43.3km/h was slightly higher than last April's 40.5km/h. Last month's average was 43.5km/h. The strongest gust of the month came on the 12th, a 72km/h south southwesterly gust, which was coincidentally the same speed as March's strongest. The calmest day was only a couple of days earlier on April 10. A strongest gust of only 20km/h was recorded then making it the lowest of the year so far and also the lowest since July 13 last year.

Cold May Day in Finland

Like it was for many other countries, yesterday was May Day in Finland, or, as the Finns call it, Vappu. This time of year can be a bit of lottery when it comes to temperatures. I don't have the exact records from before 2009, but I distinctly remember May Day Eve in 2008 getting to around 20C. In contrast, May Day Eve this year only reached 4.6C.

The graph below shows temperatures for April 30, represented by the orange lines, and May 1, dark green lines, between 2009 and 2014.

Temperatures for April 30 (orange) and May 1 (green) at Jyväskylä Airport for the period 2009-2014

Both May Day Eve and May Day were the coldest respective days during the last 6 years. Wednesday's top of only 4.6C was the first day with a maximum below 5C in almost 3 weeks. It felt especially cold after the 17C days at the end of last week too. It was also the latest date before summer for a maximum below 5C in the past 6 years, pipping 2010's April 29 recording of 3.6C by one day.

The minimum of -5.9C yesterday is actually the lowest May temperature recorded at Jyväskylä Airport since 2009. The lowest between 2009 and 2013 was -3.5C, recorded in 2012. Yesterday's low also set the latest date before summer for a temperature below -5C, beating April 26 from 2010. For further comparison, the last time below -5C in 2011 was April 1. This morning, however, reset that record when it dropped to -5.3C.

Although May Day's maximum of 6.7C was the lowest for that date, it was only the third lowest May maximum since 2009. May 8 2010 holds the current record when it only got to 5.7C.

The next week will see cooler temperatures continue in Jyväskylä. According to current forecasts, it looks like this will be the coldest start to May in at least the last 6 years.