Thursday, 1 September 2011 - Monthly Climate Summary for Tasmania - Product code IDCKGC27R0

Tasmania in August 2011: Record warmth, more flooding in the northeast

Nights were much warmer than average in August 2011, with several sites setting records. Heavy rain and flooding was experienced on two occasions in the northeast, whilst the west of the state was comparatively dry.

• Record high minimum temperatures
• Hobart nights record 2.9 °C above average
• Heavy rain and major flooding in the northeast
• 153 mm in a day at Cornwall

A summary for all of winter has also been prepared.

Extremes Maps Records Summaries Important notes the top

Record warm August nights

Average minimum temperatures were generally 2 to 3 °C warmer than usual, with many sites, including Hobart and Launceston recording their highest August mean daily minimum temperature on record. Most locations had no more than a handful of nights that were cooler than average. This was due largely to slow moving high pressure systems in the Tasman Sea directing mild northerly winds over Tasmania, and reducing the strength of cold fronts reaching the state.

On the 4th, Flinders Island Airport had a record warm night. The 6 am temperature (20.5 °C) and 9 am temperature (21.1 °C) were August records for those times of the day. The 6 am temperature was also a Tasmanian state record for 6 am in August. It is unusual to get such high morning temperatures that early in August: most of the high August temperatures are later in the month. Some other sites had record warm temperatures on the 10th and around the 18th.

One or two very cold nights

Despite the record warmth, there were a few very cold nights around the 11th and 12th, when subzero temperatures were observed at a number of locations. Strahan recorded its coldest August night on record on the 11th when the temperature dropped to -1.8 °C and the coldest night overall was at Liawenee with -7.5 °C on the 12th.

Many warm days

On the 4th, temperatures at several locations approached 20 °C, and Flinders Island reached 22.2 °C on both the 4th and 5th. This is very close to the August state record of 25.0 °C at Campania, but this occurred on the 31st in 2006: it is very unusual to have such warm weather so early in August.

The last two weeks of August were also warm as mild northerly winds maintained above average temperatures. A few locations across Tasmania experienced their highest August mean daily maximum temperature on record.

Record warm overall

On many measures, Tasmania had its warmest August on record. Several individual sites had their highest August mean temperature on record. Averaged across the state, maximum temperatures, minimum and mean temperatures were highest on record. The state-wide mean temperature was 9.1 °C, which is 2.5 °C warmer than average. The previous warmest August was in 1982, when the mean temperature was 8.3 °C.

Heavy rain and major flooding in the northeast

August saw major flooding in the northeast of Tasmania, with the region experiencing its fourth significant flooding event for the year from the 7th to the 10th, and then its fifth significant event from the 16th to the 20th.

The 7th to the 10th saw heavy rain fall across the northeast of the state. Rainfall totals for the four days exceeded 100 mm at several sites, resulting in major flooding of the South Esk and Macquarie Rivers, peaking at 9.13 m at Llewellyn, and moderate flooding of the North Esk and St Pauls Rivers. Mount Victoria received 261 mm over the four days, 141 mm of that in one day on the 9th.

From the 16th to the 19th four-day rainfall totals again exceeded 100 mm; Cornwall receiving 153 mm in one day on the 18th. This led to major flooding of the South Esk River, peaking at 9.75 m at Llewellyn, and moderate flooding of the North Esk and Macquarie Rivers.

Several roads were closed with both events, and hundreds of thousands of dollars worth of damage was made to infrastructure. The second event was exacerbated by already wet ground and a high water table following the first flooding event, with landslips and some roads washing away.

Dry in the west

In contrast to the northeast of Tasmania, August rainfall was below average in the west of the state as slow moving high pressure systems kept rain bearing cold fronts at bay. There were still some rain events, with cold fronts delivering rainfall in the first week, and up to 90 mm between the 26th to the 29th.

Hobart: Warmest August nights on record

Minimum temperatures were 2.9 °C above average in Hobart this August. The average minimum temperature of 8.1 °C is the highest August mean daily minimum temperature on record in Hobart (where standard instruments were installed in 1895), beating the previous record set in 2009 by 0.9 °C. There was a distinct lack of cold nights, with the temperature only falling to 5 °C or below on 2 days, compared to the average of 15.

Days were noticeably warm too. The maximum temperature exceeded 20 °C twice (21.7 °C on the 24th and 20.2°C on the 25th); this does not normally happen at all in August.  The overall average maximum temperature was 14.7 °C which is 1.7 °C above the August average.

Hobart received 53.2 mm of rain for the month, which is almost right on the August average, and almost exactly half the amount of rain received in August last year. The wettest day was on the 6th when a cloud band delivered 12.6 mm.

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Extremes in August 2011
Hottest day	22.2 °C at Flinders Island Airport on the 4th and 5th
Warmest days on average	15.8 °C at Flinders Island Airport
Coolest days on average	5.4 °C at Mount Wellington
Coldest day	0.4 °C at Mount Wellington on the 14th
Coldest night	-7.5 °C at Liawenee on the 12th
Coolest nights on average	0.7 °C at Mount Wellington
Warmest nights on average	9.9 °C at Swan Island
Warmest night	13.7 °C at Cape Sorell on the 25th
Warmest on average overall	12.3 °C at Eddystone Point
Coolest on average overall	3.1 °C at Mount Wellington
Wettest overall	510.4 mm at Mount Victoria (Una Plain)
Driest overall	35.8 mm at Hobart Airport
Wettest day	141.4 mm at Mount Victoria (Una Plain) on the 9th
Highest wind gust	126 km/h at Maatsuyker Island Lighthouse on the 25th and at Scotts Peak Dam on the 28th

Extremes Maps Records Summaries Important notes the top

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Maps
	Observed	Anomaly	Decile rank
Total rainfall
Mean daily maximum temperatures
Mean daily minimum temperatures

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

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Record highest August daily rainfall
	Highest daily rainfall in August 2011 (mm)		Previous wettest for August		Years of record
Memana (Babel Farm)	50.0	on the 7th	48.3	on the 16th in 1965	49

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Record highest total August rainfall
	Total rainfall for August 2011 (mm)	Previous wettest for August		Years of record	Average for August
Fingal (Legge Street)	198.0	189.6	in 1984	116	60.6
Scamander	188.6	180.4	in 1984	28	65.3
Mount Wellington	272.6	263.6	in 2010	25	89.2
Mount Victoria (Una Plain)	510.4	466.4	in 1970	20	269.8

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Record highest August mean daily maximum temperature
	Mean daily maximum temperature for August 2011 (°C)	Previous warmest for August		Years of record	Average for August
Eddystone Point	15.4	15.0	in 2007	53	13.6
Flinders Island Airport	15.8	15.2	in 1982	49	13.7
Marrawah	13.9	13.7	in 1993	40	12.7
Mount Wellington	5.4	5.3	in 2006	30	2.7
Strathgordon Village	12.3	11.1	in 1999	29	9.9
Wynyard Airport	14.3	= 14.3	in 2009	24	13.2
Dover	14.2	= 14.2	in 1993	21	13.1
Lake St Clair National Park	10.3	9.8	in 1999	20	8.1

Highest August mean daily maximum temperature for at least 20 years
	Mean daily maximum temperature for August 2011 (°C)	Most recent August at least this warm		Years since warmer	Average for August
Maatsuyker Island Lighthouse	12.6	12.7	in 1977	34	11.2
Cape Bruny Lighthouse	13.7	14.0	in 1982	29	11.9
Burnie (Round Hill)	14.4	15.1	in 1982	28	13.1
Tarraleah Village	11.1	11.6	in 1982	28	9.4
Launceston (Ti Tree Bend)	14.8	15.1	in 1982	26	13.8

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Record highest August daily minimum temperature
	Highest daily minimum temperature in August 2011 (°C)		Previous warmest for August		Years of record	Average for August
Bushy Park (Bushy Park Estates)	11.9	on the 18th	10.6	on the 25th in 1970	50	2.3
Burnie (Round Hill)	13.3	on the 10th	12.7	on the 30th in 2005	46	6.1
Launceston (Ti Tree Bend)	11.5	on the 18th	= 11.5	on the 17th in 1995	29	3.6
Fingal (Legge Street)	11.4	on the 19th	11.1	on the 10th in 2007	26	1.2
Wynyard Airport	12.9	on the 10th	12.4	on the 30th in 2005	25	4.0

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Record lowest August temperature
	Lowest temperature in August 2011 (°C)		Previous coolest for August		Years of record	Average for August
Strahan Aerodrome	-1.8	on the 11th	-1.5	on the 15th in 2004	20	5.8

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Record highest August mean daily minimum temperature
	Mean daily minimum temperature for August 2011 (°C)	Previous warmest for August		Years of record	Average for August
Hobart (Ellerslie Road)	8.1	7.2	in 2009	116*	5.2
Bushy Park (Bushy Park Estates)	5.4	4.7	in 2009	75	2.3
Maatsuyker Island Lighthouse	8.5	8.1	in 1980	74	6.4
Burnie (Round Hill)	8.6	7.8	in 2009	61	6.1
Eddystone Point	9.1	8.6	in 2009	53	7.2
Hobart Airport	7.4	7.1	in 2009	53	4.7
Orford (Aubin Court)	7.1	6.7	in 2009	43	4.2
Bicheno (Council Depot)	8.2	8.1	in 2007	36	6.3
Scottsdale (West Minstone Road)	6.2	5.6	in 2009	31	3.8
Mount Wellington	0.7	0.2	in 1999	30	-1.8
Strathgordon Village	5.9	5.6	in 1982	29	3.6
Tarraleah Village	3.7	2.8	in 2005	29	0.8
Launceston (Ti Tree Bend)	6.7	6.6	in 2009	28	3.6
Scamander	7.5	= 7.5	in 2009	27	5.2
Fingal (Legge Street)	4.8	4.5	in 2009	25	1.2
Geeveston (Cemetery Road)	5.8	= 5.8	in 2009	24	2.8
Dover	6.7	5.8	in 2009	21	3.9
Lake Leake (Elizabeth River)	4.3	3.2	in 2009	21	0.7
Lake St Clair National Park	2.6	1.9	in 2009	20	0.1

*Note: Hobart's temperature record extends back to 1882, but a standard Stevenson screen was not installed until 1895.

Highest August mean daily minimum temperature for at least 20 years
	Mean daily minimum temperature for August 2011 (°C)	Most recent August at least this warm		Years since warmer	Average for August
Marrawah	8.5	8.6	in 1980	31	7.0
Cape Bruny Lighthouse	7.9	8.0	in 1983	28	6.3

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Record highest August mean temperature
	Mean daily temperature for August 2011 (°C)	Previous warmest for August		Years of record	Average for August
Hobart (Ellerslie Road)	11.4	11.3	in 1982	116	9.1
Bushy Park (Bushy Park Estates)	10.3	9.4	in 1982	75	7.7
Maatsuyker Island Lighthouse	10.6	10.2	in 1980	74	8.8
Burnie (Round Hill)	11.5	11.0	in 1982	61	9.6
Eddystone Point	12.3	11.7	in 2009	53	10.4
Hobart Airport	11.0	= 11.0	in 1982	53	9.1
Flinders Island Airport	12.0	11.9	in 1982	49	10.2
Marrawah	11.2	11.0	in 2009	40	9.8
Scottsdale (West Minstone Road)	9.9	9.6	in 1999	31	8.2
Mount Wellington	3.0	2.6	in 2006	30	0.4
Strathgordon Village	9.1	8.4	in 1982	29	6.8
Tarraleah Village	7.4	6.7	in 1982	29	5.1
Launceston (Ti Tree Bend)	10.8	10.5	in 2009	28	8.7
Fingal (Legge Street)	9.4	9.1	in 2009	25	7.2
Geeveston (Cemetery Road)	10.0	9.7	in 2005	24	7.9
Dover	10.5	10.0	in 2005	21	8.5
Lake Leake (Elizabeth River)	7.2	6.6	in 2009	21	5.1
Lake St Clair National Park	6.4	5.2	in 1999	20	4.1

Highest August mean temperature for at least 20 years
	Mean daily temperature for August 2011 (°C)	Most recent August at least this warm		Years since warmer	Average for August
Orford (Aubin Court)	10.8	10.9	in 1982	29	9.1

Extremes Maps Records Summaries Important notes the top

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Summary statistics for August 2011
	Maximum temperatures for August (°C)				Minimum temperatures for August (°C)				Rainfall for August (millimetres)
	Mean for August 2011	Diff from average	Highest for August 2011		Mean for August 2011	Diff from average	Lowest for August 2011		Total for August 2011	Average for August	Rank of August 2011	Fraction of August average
Northern (district 91)
Bridport (Sea View Villas)	14.3	+0.6	16.2	25th	6.6	+0.8	2.0	30th	93.0	87.6	average	106%
Burnie (Round Hill)	14.4	+1.3	16.9	9th	8.6	+2.5	3.4	12th	123.1	109.9	average	112%
Cape Grim	13.3		15.6	19th	9.3		4.3	11th	123.8
Cape Grim BAPS (Comparison)	13.6	+0.9	16.2	22nd	9.1	+0.8	4.3	11th	121.8	91.6	high	133%
Cressy Research Station	13.6	+0.6	18.4	19th	5.6	+3.2	-1.6	12th	67.2	72.8	average	92%
Devonport Airport	13.9	+0.8	17.3	19th	7.4	+2.4	2.6	12th	90.8	90.4	average	100%
Launceston (Ti Tree Bend)	14.8	+1.0	18.5	19th	6.7	+3.1	1.8	26th	87.4	86.8	average	101%
Launceston Airport	13.6		17.8	19th	6.1		0.8	26th	72.2
Low Head	13.4	+0.3	15.9	19th	9.1	+1.9	5.6	22nd	98.2	81.8	high	120%
Luncheon Hill (Forestry)	12.6	+1.3	17.5	22nd	6.8	+1.8	2.8	30th	180.0	202.7	average	89%
Marrawah	13.9	+1.2	17.5	22nd	8.5	+1.5	3.5	11th	155.6	131.9	average	118%
Scottsdale (West Minstone Road)	13.6	+1.0	16.9	19th	6.2	+2.4	-0.5	11th	118.0	120.6	average	98%
Sheffield School Farm	12.4	+0.8	14.9	24th	5.7	+1.8	-1.8	11th	136.8	130.9	average	105%
Smithton Aerodrome	14.4	+0.7	17.1	24th	6.1	+0.7	-0.6	11th	133.0	117.1	average	114%
Wynyard Airport	14.3	+1.1	16.8	9th	5.9	+1.9	-1.4	11th	145.0	113.6	high	128%
East Coast (district 92)
Bicheno (Council Depot)	15.4	+0.7	22.0	4th	8.2	+1.9	3.2	12th	88.6	51.5	high	172%
Eddystone Point	15.4	+1.8	18.7	24th	9.1	+1.9	4.3	12th	133.2	72.1	high	185%
Fingal (Legge Street)	14.1	+0.8	19.8	4th	4.8	+3.6	-1.5	30th	198.0	60.4	highest	328%
Friendly Beaches	15.0	+0.3	21.4	4th	8.2	+2.0	1.2	12th	107.4	61.0	high	176%
Lake Leake (Elizabeth River)	10.2	+0.8	14.1	4th	4.3	+3.6	-0.9	26th	190.2	79.3	v high	240%
Maria Island (Point Lesueur)	13.8		18.8	4th	9.2		4.8	12th	50.8
Orford (Aubin Court)	14.4	+0.4	19.4	4th	7.1	+2.9	1.8	12th	83.6	62.3	high	134%
Scamander	15.0	+0.2	21.5	4th	7.5	+2.3	3.0	12th	188.6	65.3	highest	289%
St Helens Aerodrome	14.9	+0.6	19.9	4th	7.8	+2.6	1.9	12th	179.8	74.2	v high	242%
Swan Island	14.0		16.3	2nd	9.9		6.8	12th	147.6
Midlands (district 93)
Ross (The Boulevards)	13.4	+0.8	18.6	19th	5.4	+3.1	-2.8	12th	56.8	49.3	average	115%
Southeast (district 94)
Bull Bay (Lauriston)	13.9	+0.6	20.0	24th	8.0	+2.1	2.5	12th	52.5	56.6	average	93%
Campania (Kincora)	15.4	+1.1	21.3	24th	6.4	+2.4	1.8	15th
Cape Bruny (Cape Bruny)	13.8	+1.0	19.8	25th	8.2	+1.6	3.8	12th	54.6	91.3	low	60%
Cape Bruny Lighthouse	13.7	+1.8	19.1	25th	7.9	+1.6	3.9	12th	49.9	93.1	v low	54%
Dover	14.2	+1.1	20.2	25th	6.7	+2.8	0.0	12th	104.4	89.8	average	116%
Geeveston (Cemetery Road)	14.1	+1.2	20.1	25th	5.8	+3.0	0.6	12th	125.0	104.1	average	120%
Grove (Research Station)	14.5		21.0	24th	5.9		-0.5	12th	77.8
Hobart (Ellerslie Road)	14.7	+1.7	21.7	24th	8.1	+2.9	1.7	12th	53.2	53.6	average	99%
Hobart Airport	14.6	+1.2	21.4	24th	7.4	+2.7	2.0	12th	35.8	46.9	average	76%
Maatsuyker Island Lighthouse	12.6	+1.4	16.8	16th	8.5	+2.1	4.7	29th	75.2	123.2	low	61%
Melton Mowbray (North Stockman)	13.4	+0.8	19.4	24th	5.6	+3.0	-3.8	12th	60.4	51.8	average	117%
Mount Wellington	5.4	+2.7	10.8	19th	0.7	+2.5	-3.7	30th	272.6	89.2	highest	306%
Tasman Island	11.9		17.6	4th	7.6		4.0	29th	61.6	81.0	average	76%
Tunnack Fire Station	11.4	+0.8	15.8	19th	4.8	+2.8	-2.6	12th	99.8	66.2	high	151%
Derwent Valley (district 95)
Bushy Park (Bushy Park Estates)	15.2	+2.1	21.5	24th	5.4	+3.1	-1.3	12th	49.0	54.0	average	91%
Maydena Post Office	13.3	+1.4	19.0	25th	5.1	+2.6	-1.5	12th	119.4	153.1	low	78%
Ouse Fire Station	14.6	+1.0	20.8	24th	5.3	+3.3	-1.5	12th	54.2	63.4	average	85%
Tarraleah Village	11.1	+1.7	16.5	24th	3.7	+2.9	-1.9	12th	132.0	127.1	average	104%
Central Plateau (district 96)
Butlers Gorge	10.4	+2.5	16.7	19th	2.7	+2.7	-5.0	12th	154.2	182.5	average	84%
Lake St Clair National Park	10.3	+2.2	16.2	20th	2.6	+2.5	-3.7	12th	163.4	246.7	low	66%
Liawenee	8.2	+1.6	14.2	19th	1.0	+2.2	-7.5	12th	132.0	142.5	average	93%
West Coast (district 97)
Cape Sorell	14.5	+2.4	17.2	21st	9.6	+2.3	4.9	11th
Hartz Mountain (Keoghs Pimple)	8.2	+1.6	14.9	19th	3.1	+1.7	-0.5	30th	136.0	118.1	average	115%
Mount Read	6.3	+2.3	11.2	19th	2.0	+2.0	-2.1	29th	241.5
Scotts Peak Dam	12.6	+2.3	20.4	19th	5.7	+2.3	0.9	29th	163.2	210.8	low	77%
Strahan Aerodrome	14.7	+1.6	18.4	16th	7.4	+1.6	-1.8	11th	92.6	170.4	low	54%
Strathgordon Village	12.3	+2.4	16.2	23rd	5.9	+2.3	-0.4	11th	215.1	290.9	low	74%
Warra	10.8		17.0	25th	4.6		-0.4	12th	206.4
King Island (district 98)
King Island Airport	14.7	+1.1	18.4	3rd	8.5	+0.7	3.3	12th	95.6	117.2	average	82%
Flinders Island (district 99)
Flinders Island Airport	15.8	+2.1	22.2	5th	8.1	+1.5	0.8	8th	77.4	76.1	average	102%
Hogan Island	14.5		20.3	4th	9.7		7.1	30th	40.8
Antarctica and Macquarie Island (district 300)
Macquarie Island	4.9	-0.1	7.7	23rd	1.3	-0.3	-4.6	14th	72.8	73.1	average	100%

Extremes Maps Records Summaries Important notes the top

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