Tasmania in September 2011: Dry in the north and east

Rainfall was below average across the north and east of Tasmania in September 2011, in marked contrast to August.

  • Below average rainfall in the north and east
  • Warmer than normal days
  • Night time temperatures near average
  • Record high September temperature of 20 C at Devonport Airport on the 28th.

Dry in the north and east

Westerly winds prevailed for much of the month and several cold fronts crossed the state. This ensured monthly rainfall totals in the west were close to average. However, there were few rain-bearing systems that reached the north and east, so totals were well below average there. The wettest period was the 20th to the 23rd, with other wet periods including the 5th to the 11th, the 14th to the 18th, and the 29th to 30th. Mount Read had the state’s wettest day of the month on the 22nd when 50 mm was recorded. It was also the wettest location overall with a monthly total of 470 mm.

More mild days than cold

Average daytime temperatures were generally up to one degree warmer than normal. The warmest periods were around the first and third weeks of September and the 27th to 28th when milder northerly winds prevailed for much of the time. The warmest individual day was the 28th when temperatures at several locations exceeded 20 C, peaking at 23.9 C in Hobart. Devonport Airport recorded 20.0 C, its highest September temperature on record. The coolest period was around the 7th to the 12th and the 23rd to 25th when cold southwesterly winds prevailed. The coldest day was at Mount Wellington when the temperature only reached a maximum of -1.1 C on the 11th.

Near average night time temperatures

Cold nights and warm nights were interspersed throughout September. The warmest were around the 4th, 22nd and 29th under the influence of mild northerly winds, whilst the coldest were around the 2nd, 19th and the 24th to the 26th when conditions were generally still and clear. Nights were also cold around the 7th, 8th, 11th and 12th when southwesterly winds directed cold air over Tasmania. The lowest temperature of the month was -5.1 C recorded at Butlers Gorge on the 19th, whilst the mildest morning was 13.7 C at Flinders Island on the 29th. Overall, night time temperatures were up to a degree warmer than average in the south and west, and up to one degree cooler than average in the east.

Hobart: warm September days

September days were warmer than normal in Hobart, averaging 16.3 C (1.2 C above average). The warmest days were from the 2nd to the 6th, the 12th to the 22nd and the 26th to 29th in mild northerly winds. Every day from the 16th to the 22nd was warmer than 17 C; the last time Hobart had seven consecutive September days over 17 C was in 2000. In total, there were 14 days where the temperature was 17 C or more (almost double the average of 8 days), and only 2 days where the maximum temperature remained below 12 C (against an average of 5 such cold days).

Night time conditions were just warmer than normal for September, averaging 7.1 C. The coldest morning was on the 2nd when the temperature fell to 3.2 C and the warmest on the 22nd and 29th when the temperature only dropped to 12.0 C.

It was drier than average in Hobart for most of September. A cold front delivered 14 mm on the last two days which raised the monthly total to 46 mm, close to half the 88 mm received last year but only 8 mm below the long-term average. Days were generally sunnier due to the lack of cloud; Hobart Airport averaging 7 hours of bright sunshine per day which is about an hour more than normal for September.

Further information

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Extremes in September 2011
Hottest day 23.9 C at Hobart (Ellerslie Road) on the 28th
Warmest days on average 17.0 C at Friendly Beaches
Coolest days on average 5.4 C at Mount Wellington
Coldest day -1.1 C at Mount Wellington on the 11th
Coldest night -5.1 C at Butlers Gorge on the 19th
Coolest nights on average -0.6 C at Mount Wellington
Warmest nights on average 9.6 C at Hogan Island
Warmest night 13.7 C at Flinders Island Airport on the 29th
Warmest on average overall 12.4 C at Eddystone Point
Coolest on average overall 2.4 C at Mount Wellington
Wettest overall 470.4 mm at Mount Read
Driest overall 15.2 mm at Swansea (Francis Street)
Wettest day 49.6 mm at Mount Read on the 22nd
Highest wind gust 135 km/h at Cape Grim BAPS on the 23rd

Maps

ObservedAnomalyDecile rank
Total
rainfall
Map of Rainfall totals Map of Percentage of normal rainfall Map of Rainfall deciles
Mean
daily
maximum
temperatures
Map of Mean maximum temperature Map of Anomaly in mean maximum temperature Map of Decile rank of mean maximum temperature
Mean
daily
minimum
temperatures
Map of Mean minimum temperature Map of Anomaly in mean minimum temperature Map of Decile rank of mean minimum temperature

Click on a map to show it full size in a pop-up window


Record highest September temperature

Highest temperature
in September 2011 (C)
Previous warmest
for September
Years of
record
Average for
September
Devonport Airport 20.0 on the 28th 19.6 on the 20th in 2010 20 14.1



Record highest September mean daily maximum temperature

Mean daily maximum
temperature
for September 2011 (C)
Previous warmest
for September
Years of
record
Average for
September
Eddystone Point 16.8 16.7 in 2001 53 14.8
Wynyard Airport 15.6 = 15.6 in 2009 23 14.3


Summary statistics for September 2011

Maximum temperatures
for September
(C)
Minimum temperatures
for September
(C)
Rainfall
for September
(millimetres)
Mean for
September
2011
Diff
from
average
Highest for
September
2011
Mean for
September
2011
Diff
from
average
Lowest for
September
2011
Total for
September
2011
Average
for
September
Rank of
September
2011
Fraction of
September
average
Northern (district 91)
Bridport (Sea View Villas) 15.3 +0.6 19.6 28th     2.0 25th 40.1 74.3 v low 54%
Burnie (Round Hill) 15.6 +1.3 17.6 1st 7.7 +0.9 3.5 7th 73.2 87.4 average 84%
Cape Grim 13.6   17.2 22nd 9.0   5.0 24th 57.4


Cape Grim BAPS (Comparison) 13.8 +0.4 17.5 22nd 8.9 +0.3 5.2 24th 66.0 76.6 average 86%
Cressy Research Station 15.3 +0.7 20.2 28th 4.1 +0.2 -2.5 8th 35.8 61.7 v low 58%
Devonport Airport 15.5 +1.4 20.0 28th 6.4 +0.4 1.1 24th 48.2 74.4 low 65%
Launceston (Ti Tree Bend) 16.6 +1.1 22.5 28th 5.1 -0.1 0.1 8th 29.0 65.9 low 44%
Launceston Airport 15.7   22.2 28th 4.0   -0.7 1st 26.4


Low Head 14.6 +0.7 18.2 28th 8.8 +0.4 4.0 24th 52.8 65.7 low 80%
Luncheon Hill (Forestry) 13.3 +1.0 18.8 28th 5.6 +0.2 0.9 24th 112.2 175.4 low 64%
Marrawah 14.3 +0.7 18.3 22nd 7.9 +0.5 3.7 25th 77.2 105.1 low 73%
Scottsdale (West Minstone Road) 14.8 +0.6 20.6 28th 4.8 +0.1 -1.2 8th 52.2 98.4 low 53%
Sheffield School Farm 13.7 +0.7 18.4 28th 4.8 +0.1 -0.8 24th 52.6 123.6 v low 43%
Smithton Aerodrome 15.2 +0.4 18.4 28th 5.9 -0.3 -0.2 24th 61.8 104.0 low 59%
Wynyard Airport 15.6 +1.3 18.3 29th 4.6 -0.3 -0.7 24th 65.8 95.2 low 69%
East Coast (district 92)
Bicheno (Council Depot) 16.7 +0.6 21.6 4th 7.5 +0.2 2.3 2nd 36.6 44.3 average 83%
Eddystone Point 16.8 +2.0 21.5 28th 8.0 0.0 3.6 10th 41.8 63.3 average 66%
Fingal (Legge Street) 15.8 +0.6 19.5 3rd 2.2 -1.1 -3.7 8th 17.4 49.3 low 35%
Friendly Beaches 17.0 +0.4 22.1 4th 7.3 -0.2 1.4 25th 28.2 37.3 average 76%
Lake Leake (Elizabeth River) 12.0 +0.7 19.3 28th 1.7 -0.3 -3.2 25th 44.2 70.8 low 62%
Maria Island (Point Lesueur) 14.9   19.7 21st 8.3   5.3 8th 35.4


Orford (Aubin Court) 15.8 +0.1 21.4 4th 5.3 -0.2 0.0 8th 35.6 51.6 average 69%
Scamander 16.6 +0.3 20.8 16th 6.4 -0.3 1.5 12th 29.2 54.0 low 54%
St Helens Aerodrome 16.2 +0.4 19.6 16th 6.3 -0.3 0.7 12th 41.0 49.3 average 83%
Swan Island 15.2   18.2 22nd 9.3   6.4 7th 54.0


Swansea (Francis Street) 16.6   22.0 4th 5.6   -0.4 25th 15.2


Midlands (district 93)
Ross (The Boulevards) 14.8 +0.4 20.5 28th 3.3 -0.3 -2.9 25th 41.0 53.0 average 77%
Southeast (district 94)
Campania (Kincora) 16.1 0.0 23.7 28th 4.9 -0.3 -1.0 2nd 30.2 49.0 low 62%
Cape Bruny (Cape Bruny) 14.4 +0.1 21.1 28th 7.4 0.0 4.9 25th 61.0 70.1 average 87%
Cape Bruny Lighthouse 14.0 +0.8 20.3 28th 6.9 -0.1 1.6 10th 70.2 81.3 average 86%
Dover 14.7 +0.1 21.7 22nd 5.2 +0.3 0.0 2nd 70.8 84.0 average 84%
Geeveston (Cemetery Road) 15.0 +0.3 22.1 28th 5.3 +0.9 -1.1 2nd 80.8 93.5 average 86%
Grove (Research Station) 15.3   22.7 28th 4.5   -2.1 2nd 55.4


Hobart (Ellerslie Road) 16.3 +1.2 23.9 28th 7.1 +0.7 3.2 2nd 45.6 53.4 average 85%
Hobart Airport 15.9 +0.6 22.3 28th 6.4 +0.4 1.9 2nd 30.2 42.2 average 72%
Maatsuyker Island Lighthouse 12.6 +0.4 21.7 28th 7.5 +0.7 4.0 7th 135.8 109.7 high 124%
Melton Mowbray (North Stockman) 14.5 0.0 20.1 28th 4.2 -0.2 -1.4 25th 26.6 53.4 v low 50%
Mount Wellington 5.4 +1.1 12.4 28th -0.6 +0.8 -3.8 24th 53.6 71.3 average 75%
Tasman Island 12.5   18.0 22nd 7.1   3.5 10th 74.4 87.3 average 85%
Tunnack Fire Station 12.5 +0.1 18.8 28th 3.3 0.0 -3.4 25th 35.0 65.6 low 53%
Derwent Valley (district 95)
Bushy Park (Bushy Park Estates) 16.2 +0.8 23.4 28th 4.0 +0.1 -1.4 2nd 43.2 54.2 average 80%
Maydena Post Office 13.3 -0.3 21.2 28th 3.7 +0.3 -1.5 25th 137.3 142.3 average 96%
Ouse Fire Station 15.7 +0.1 22.8 28th 4.2 +0.4 -2.0 2nd 42.6 73.4 low 58%
Tarraleah Village 11.5 +0.4 19.0 28th 3.0 +1.2 -1.5 19th 140.0 120.8 average 116%
Central Plateau (district 96)
Butlers Gorge 10.4 +0.4 19.4 28th 1.8 +0.9 -5.1 19th 182.4 169.3 average 108%
Lake St Clair National Park 10.5 +0.5 18.3 28th 1.5 +0.7 -3.1 2nd 237.6 217.2 average 109%
Liawenee 8.9 +0.2 14.8 28th -0.1 +0.6 -3.9 24th 87.0 123.8 low 70%
West Coast (district 97)
Cape Sorell 14.4 +1.3 20.0 28th 8.7 +0.9 5.0 25th 108.6 123.2 average 88%
Hartz Mountain (Keoghs Pimple) 8.2 -0.3 16.4 28th 2.0 +0.3 -1.0 9th 96.8 101.7 average 95%
Mount Read 5.6 +0.3 13.7 28th 0.6 +0.3 -2.5 7th 470.4 379.2 average 124%
Scotts Peak Dam 12.1 0.0 22.4 28th 4.3 0.0 1.3 24th 252.0 222.1 average 113%
Strahan Aerodrome 15.3 +1.1 23.5 28th 6.8 +0.6 0.9 2nd 170.8 155.1 average 110%
Strathgordon Village 11.8 +0.3 21.4 28th 4.3 -0.1 0.0 2nd 314.1 281.9 average 111%
Warra 11.4   19.4 28th 3.3   -1.5 25th 213.2


King Island (district 98)
King Island Airport 15.5 +1.0 21.5 22nd 8.5 +0.2 3.1 24th 56.8 87.7 low 65%
Flinders Island (district 99)
Flinders Island Airport 16.0 +1.0 21.4 28th 8.2 +0.7 -1.0 25th 36.0 63.6 low 57%
Hogan Island 14.7   20.4 19th 9.6   5.7 7th 52.2


Antarctica and Macquarie Island (district 300)
Macquarie Island 5.9 +0.6 8.3 29th 1.7 +0.2 -3.3 1st 82.0 74.6 average 110%

Notes

A Monthly Climate Summary is prepared to list the main features of the weather in Tasmania 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.

This statement has been prepared based on information available at 9 am on Monday 3 October 2011. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

Averages 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.

Further information

Media
(03) 9669 4057
Enquiries