Brisbane in autumn 2015: a wetter than normal season; warmer days and nights overall

  • Warmer than usual days and nights
  • Above average rainfall
  • Numerous heavy rainfall events throughout the season

Autumn rainfall in the metropolitan area was above average with all sites recording more than 290 mm of rainfall for the season, and some sites recording twice their average rainfall. Brisbane's 556.4 mm for the season was the wettest autumn at the current station (open in 1999) and the wettest autumn in the Brisbane CBD since 1990.
There were several heavy rainfall events during autumn. In March, a slow-moving trough and upper level system on the 21st brought widespread rainfall across the metropolitan area, with almost 150 mm received in Brisbane City in the 48 hours to 9am on 23rd. Some isolated, heavy falls were recorded at some sites due to thunderstorms on the 25th. 
In April, a slow-moving surface trough through the interior of Queensland, combining with an upper level disturbance over the south of the State at the start of the month, generated heavy rainfall in the Brisbane metropolitan area. Some daily rainfall totals exceeded 100 mm were recorded to 9am on the 1st - including Brisbane Airport with 126.2 mm, its highest daily rainfall on record for April. Rainfall continued across Brisbane until the 5th. More rain fell across Brisbane between the 18th and 20th as a surface trough extended along the east coast and southeast of Queensland. A surface trough and upper level disturbance over southern Queensland generated brought light rainfall to the Brisbane metropolitan area at the end of the month. Brisbane Airport also recorded its highest monthly April rainfall in 20 years.
In May, h
eavy rain fell across the metropolitan area at the start of the month, as a deepening surface trough and low pressure system developed near the border between Queensland and New South Wales. Flash flooding occurred in northern Brisbane suburbs and Caloundra, with some places recorded their highest daily May rainfall on record.
Autumn daytime and overnight temperatures were above average across the metropolitan area, with a mixture of hot days and cold nights. 

The warmest autumn day occurred on 5 March, and the coldest night was on 15 May. March was an exceptionally warm month in the Brisbane metropolitan area, with a particularly hot spell on the 5th, and more hot weather on 19th. 
In April, daytime temperatures were cool on the 1st, and then temperatures returned to near-average for the first half of the month. Very cold days were experienced on the 20th and 21st, as cold and dry southerly air entered the State, all metropolitans site recorded daytime temperature between 5 and 6 C below average. Cold days also occurred at the end of April. Overnight temperatures were warmer than average in the first week of April, before several days of cold nights between the 8th and 17th. Warm overnight conditions returned until the 20th, before a run of colder than usual nights to the end of the month. 
In May, daytime and overnight temperatures were both near-average, with some warmer days persisting during the first half of the month, but somewhat cooler from mid-month onwards. Overnight temperatures were generally  mild throughout the metropolitan area, with cooler than usual nights in the second week of the month.

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Extremes in autumn 2015
Hottest day 37.9 C at Amberley AMO on 5 Mar
Warmest days on average 27.1 C at Amberley AMO and at Archerfield Airport
Coolest days on average 25.9 C at Redcliffe
Coldest day 17.4 C at Amberley AMO on 30 Apr
Coldest night 1.1 C at Amberley AMO on 15 May
Coolest nights on average 14.1 C at Amberley AMO
Warmest nights on average 17.9 C at Redcliffe
Warmest night 25.2 C at Redcliffe on 21 Mar
Warmest on average overall 22.2 C at Brisbane
Coolest on average overall 20.6 C at Amberley AMO
Wettest overall 583.8 mm at Hilltop Gardens
Driest overall 292.4 mm at Amberley AMO
Wettest day 213.6 mm at Boondall on 2 May
Strongest wind gust 72 km/h at Redcliffe on 5 Mar and at Brisbane Aero on 26 Apr

Record highest autumn daily rainfall
New record
(mm)
Old
record
Years of
record
Boondall 213.6 on 2 May 182.4 on 2 May 1996 39



Record highest autumn temperature
New record
(C)
Old
record
Years of
record
Average for
autumn
Logan City Water Treatment Plant 37.5 on 5 Mar 35.5 on 22 Mar 2011 23 26.2



Record highest autumn daily minimum temperature
New record
(C)
Old
record
Years of
record
Average for
autumn
Logan City Water Treatment Plant 24.9 on 21 Mar = 24.9 on 26 Mar 2001 23 15.8
Brisbane Aero 25.0 on 21 Mar 24.7 on 26 Mar 2001 21 16.3



Summary statistics for autumn 2015
Maximum temperatures
(C)
Minimum temperatures
(C)
Rainfall
(millimetres)
Mean for
autumn
2015
Diff
from
average
Highest for
autumn
2015
Mean for
autumn
2015
Diff
from
average
Lowest for
autumn
2015
Total for
autumn
2015
Average
for
autumn
Rank of
autumn
2015
Fraction of
autumn
average
Amberley AMO 27.1 +0.3 37.9 5 Mar 14.1 +0.2 1.1 15 May 292.4 193.8 high 151%
Archerfield Airport 27.1 +0.7 36.9 5 Mar 16.0 +0.9 5.0 15 May 429.8 279.2 high 154%
Brisbane 26.9 +0.1 36.1 5 Mar 17.4 +0.5 8.1 15 May 556.4 250.5 v high 222%
Brisbane Aero 26.0 +0.2 31.2 5 Mar 16.9 +0.6 7.2 15 May 472.8 288.4 high 164%
Logan City Water Treatment Plant 26.6 +0.4 37.5 5 Mar 16.4 +0.6 6.6 15 May 575.7 316.1 v high 182%
Redcliffe 25.9 +0.3 33.8 5 Mar 17.9 +0.5 9.1 15 May 433.8 309.1 high 140%

Notes

A Seasonal Climate Summary is prepared to list the main features of the weather in Brisbane using the most timely and accurate information available on the date of publication; it will generally not be updated. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review, usually published in the fourth week of the month.

A Climate Summary is generally published on the first working day of each month.

This statement has been prepared based on information available at 10 am on Monday 1 June 2015. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

Averages for individual sites are long-term means based on observations from all available years of record, which vary widely from site to site. They are not shown for sites with less than 10 years of record, as they cannot then be calculated reliably.
The median is sometimes more representative than the mean of long-term average rain.

The Rank indicates how rainfall this time compares with the climate record for the site, based on the decile ranking (very low rainfall is in decile 1, low in decile 2 or 3, average in decile 4 to 7, high in decile 8 or 9 and very high is in decile 10).
The Fraction of average shows how much rain has fallen this time as a percentage of the long-term mean.

The ACORN-SAT dataset is used for temperature area averages.

Further information

Media
(03) 9669 4057
Enquiries