October 2014 Review - Sydney

For the third year in a row, Sydney saw an above average October. The month started off with some very warm daily maximums, but the arrival of a large storm system in the middle of the month dropped temperatures sharply. The system also brought damaging winds as well as the highest 24 hours to 9am October rainfall total for Sydney Airport in 54 years. Warmth returned as the month ended though leading to it being the fourth warmest on record.

The averages for the previous six Octobers can be seen below alongside the long term average.

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

Both averages were comfortably above the long term figure. The average maximum of 25.0C ranked as the fourth warmest October figure since records began in 1939. The top three warmest begin with the 27.0C average recorded in 1988, followed by 2013 and 2007. The Bureau of Meteorology recorded an average minimum of 15.0C, slightly above mine. This was also the fourth warmest such figure of the past 76 years. 2005's figure of 15.5C is the record, followed by 2007 and 1999.

Five days during the month topped 30C. October 5 was the hottest of those with a top of 34.4C. This was, however, the second lowest such figure since at least 2009. October 2010 didn't see one day above 30C. The highest minimum came on October 7. The 18.4C recording then ranked as the second lowest such figure in the past six years.

The lowest maximum of 15.4C was recorded on the 15th. This was the lowest daily minimum for an October day since 2008. The coldest temperature of the month was recorded twice. October 14 and 16 saw it drop just below 10C to 9.9C. This was the second highest respective figure in the years since 2009.

Daily minimums and maximums (left axis) against rainfall (right) at Sydney Airport for October 2014

October 2014 was above average in terms of rainfall and the wettest since 2009. A total of 118.8mm fell during the calendar month. The Bureau of Meteorology recorded 118.6mm. This figure is well above the long term average of 70.7mm. It was the third wettest month seen so far this year after August and March.

The month saw a total of eight rain days. There were two streaks of three rain days. Eight was also the number for the longest dry streak; from the 16th onwards. The few days prior to that saw very heavy falls as a large storm and low pressure system affected the New South Wales coast. October 14 saw 86.0mm at the Airport, the highest daily total this year. BOM's 24 hours to 9am total on the 15th was 101.0mm. This was the highest such October total since 109.0mm was recorded on the morning of October 22 way back in 1960.

The storm system that struck Sydney across October 13, 14 and 15 also brought very strong and destructive winds. The maximum wind gust for the 13th measured 76km/h. The late evening of the 14th saw southerly winds increase, and a maximum gust of 107km/h was recorded at the Airport. This is the strongest since at least the start of last year. Winds continued into the early hours of the 15th with a 102km/h gust recorded then. The calmest day was the 23rd. A strongest gust of only 28km/h was measured on that day.