Monday, 2 October 2017 - Monthly Climate Summary for Greater Sydney - Product code IDCKGC15L0

Greater Sydney in September 2017: driest September on record

September 2017 was the driest start to spring observed in Sydney since observations began in 1858. A blast of warm air towards the end of the month set many temperature records for both hottest day and warmest night.

Sydney's driest month sets new records

• Little to no rain fell across the Greater Sydney region during September: the only falls of note came in the middle of the month when a passing cold front and associated trough caused localised totals above 5 mm in parts of the central coast and isolated showers elsewhere
• Many stations had their lowest September rainfall on record including Sydney's Observatory Hill which reported only 0.2 mm, the driest September in 159 years of observations and the driest month since August 1995
• It's been 59 days since at least 2 mm was recorded at Observatory Hill, making it the longest dry spell of its kind since 22 August to 24 October 1989
• The dry weather also meant more sunshine across the city: Sydney Airport recorded an average of 9.5 sunshine hours per day for September, the sunniest September since 1980 and the sunniest month since February last year

A very warm start to spring

• The pattern of warm days in winter has continued into spring; Observatory Hill reported its second warmest September on record for maximum temperatures, while the mean maximum temperature at Parramatta North was more than 2 °C above average
• Early season warm records were set across the city on the 13th, with many sites reporting temperatures above 33 °C, more than 12 °C above their monthly average
• High temperatures returned on the weekend of the 23rd as northerly winds drew hot air in from central Australia; many stations reported their highest September maximum and minimum temperatures on record, including the warmest September night on record for Observatory Hill
• The temperatures recorded across the city were the warmest ever recorded in Greater Sydney in September: Penrith Lakes (37.3 °C), Richmond (36.9 °C), Camden (36.5 °C), Parramatta North (36.5 °C) and Badgerys Creek (36.4 °C) all beat the previous September maximum of 36.1 °C recorded at Gosford on the 26th of September 1965
• Observatory Hill reached 33.8 °C on the 13th and 32.2 °C on the 23rd, two of only 22 September days to reach more than 32 °C in the station's history; 12 of the 22 days have been recorded since 2000 and the only other Septembers with two days above 32 °C have occurred since 2008
• Observatory Hill also reported 28.1 °C at 6am on 24 September, the warmest 6am temperature out of the summer months since April 1986 and the warmest September 6am temperature there since hourly observations began in 1955

Cool nights persist in the west

• Despite the warmth on the weekend of the 23rd and 24th, minimum temperatures were slightly below average for the month as a whole, particularly in the west: a couple of sites had their lowest September mean daily minimum temperature in at least 20 years
• Overnight temperatures dropped to less than 1 °C in parts of the outer suburbs on the 17th and 18th, the coldest temperature on record so late in the spring for some stations: Badgery Creek recorded 0.5 °C on the 17th, the coldest night since 23 July

Extremes Maps Records Summaries Daily observations Important notes the top

Extremes Maps Records Summaries Daily observations Important notes the top

* note: there are gaps in the historical record at this site, so it is possible a lower value has gone unreported

Extremes Maps Records Summaries Daily observations Important notes the top

Extremes Maps Records Summaries Daily observations Important notes the top

Extremes Maps Records Summaries Daily observations Important notes the top