Monday, 1 September 2008 - Monthly Climate Summary for Tasmania - Product code IDCKGC17R0

Tasmania in August 2008: Cool with below-average rain

August 2008 was drier and cooler than usual, and also markedly cooler than August 2007. Although a number of fronts crossed the state, rainfall was below average in most areas, especially in the east and through the Midlands. Snow fell somewhere in the state on about half the days in August, and settled to low levels on two occasions.

A separate summary covering all of winter 2008 has also been prepared. An archive of previous monthly summaries for Tasmania is also available, as are summaries for other states and many other climate summaries and diagnostics.

Details

Very cold nights: Light winds and very cold air masses following cold fronts led to cooler than normal nights during August. At many locations, overnight temperatures were 2 degrees or more colder than for the same period last year, and 1 to 2 degrees below the long term average. The 10th to 13th, 18th and 22nd to 25th were especially cold. Mount Wellington dropped to −7.5°C early on the 13th, the coldest temperature recorded there since September 1994. Launceston had its lowest August mean daily minimum temperature on record, and a few other sites in the east had their lowest August mean daily minimum temperature for at least 20 years. Cloud and winds associated with a front early on the 31st meant that the last morning of the month was the warmest for most locations.

Cool days: Although not as extraordinary as the overnight temperatures, days during August were also cooler than usual. Averaged across the month, maxima were generally about half a degree below the long term average, and a degree below those of August 2007. The coldest days occurred in southwest to southerly winds on the 1st, around the 21st, and for a long run of days from the 10th to the 17th. Most locations in the north struggled to reach 10°C on the 10th, with southern locations recording similarly cold temperatures from the 12th to the 16th. Warmer conditions returned on the last few days of the month, with temperatures reaching the high teens in many areas on the 30th and 31st.

Fronts fail to deliver: Although fronts crossed the state regularly during August, rainfall totals were not impressive and most areas received below average rainfall. It was particularly dry in the east and through the Midlands where many sites received only around a quarter of their normal August rain and a few locations had their lowest total August rainfall since 1982. The highest daily totals fell in the 24 hours to 9am on the 14th when Warra recorded 69 mm and a number of locations in the west and on the Central Plateau received in excess of 40 mm.

Many falls of snow: The cold fronts which crossed Tasmania during August dragged very cold air over the state. As a result, snow fell somewhere in Tasmania on at least 14 days of the month, including on 10 consecutive days from the 8th to the 17th when a cold air mass persisted over the state due to an extended period of southwest to southerly winds. Cold fronts on the 12th and 21st caused the most significant snow events, with snow settling below 100 metres in the south and 400 metres in the north on the 12th, and almost as low again on the 21st.

Further information

Ian Barnes-Keoghan
Meteorologist
Tasmania and Antarctica Climate Services Centre
Bureau of Meteorology
Phone (03) 6221 2043
Email climate.tas@bom.gov.au

Extremes

Hottest day
Highest temperature
19.5°C at Hobart (Ellerslie Road)
and Swansea Post Office on the 31st
Warmest days on average
Highest mean daily maximum temperature
14.4°C at Eddystone Point
Coolest days on average
Lowest mean daily maximum temperature
2.2°C at Mount Wellington
Coldest day
Lowest daily maximum temperature
−2.4°C at Mount Wellington on the 15th
Coldest night
Lowest temperature
−7.9°C at Liawenee on the 22nd
Coolest nights on average
Lowest mean daily minimum temperature
−2.9°C at Liawenee
Warmest nights on average
Highest mean daily minimum temperature
8.3°C at Hogan Island
Warmest night
Highest daily minimum temperature
12.3°C at Flinders Island Airport on the 31st
Wettest overall
Highest total rainfall
259.2 mm at Lake Margaret Power Station
Driest overall
Lowest total rainfall
9.4 mm at Mount Morriston (Macquarie River)
Wettest day
Highest daily rainfall
69.0 mm at Warra on the 14th
Highest wind gust
144 km/h at Mount Wellington on the 19th

Records


Lowest total August rainfall for at least 20 years
Total rainfall
for August 2008 (mm)
Most recent lower
for August
Years since
lower
Normal for
August
Lake Leake (Elizabeth River) 21.6 8.0 in 1982 26 75.9
Rotherwood 17.4 8.2 in 1982 26 54.9
Oatlands Post Office 11.2 6.0 in 1982 25 44.7




Record lowest August mean daily minimum temperature
Mean daily minimum
temperature
for August 2008 (°C)
Previous lowest
for August
Years of
record
Normal for
August
Launceston (Ti Tree Bend) 1.7 1.9 in 1994 26 3.6


Lowest August mean daily minimum temperature for at least 20 years
Mean daily minimum
temperature
for August 2008 (°C)
Most recent lower
for August
Years since
lower
Normal for
August
Launceston Airport Comparison 1.7 1.6 in 1944 64 3.0
Flinders Island Airport 5.1 4.9 in 1976 32 6.6
Scottsdale (West Minstone Road) 2.5 1.8 in 1978 21 3.8
Swansea Post Office 3.4 3.3 in 1987 21 4.4


Summaries

In this table, key sites have been highlighted to make them easier to find. This table is very wide and may not fit if printed.


Summary statistics for August 2008
Maximum temperatures
for August
(°C)
Minimum temperatures
for August
(°C)
Rainfall
for August
(millimetres)
Mean for
August
2008
Diff
from
normal
Highest for
August
2008
Mean for
August
2008
Diff
from
normal
Lowest for
August
2008
Total for
August
2008
Normal
for
August
Rank of
August
2008
Fraction of
August
normal
Northern (district 91)
Bridport 13.3 −0.4 15.2 30th 4.9 −0.9 1.0 16th 73.4 78.5 average 94%
Burnie 13.1 0.0 16.0 27th 6.2 +0.1 2.8 22nd 69.8 109.8 low 64%
Cape Grim BAPS 12.1 −0.6 14.1 4th 7.6 −0.8 4.2 22nd 121.4 87.9 high 138%
Cressy Research Station 12.6 −0.5 16.5 30th 0.8 −1.5 −5.2 23rd 26.6 64.5 low 41%
Devonport Airport 12.9 −0.1 15.3 30th 4.0 −1.0 −1.3 22nd 44.6 88.9 low 50%
Launceston 13.7 0.0 17.6 30th 1.7 −1.9 −1.8 23rd 36.4 83.2 low 44%
Launceston Airport 12.6   16.7 30th 1.3   −3.5 13th 28.0
Launceston Airport Comparison 11.9 −0.1 15.7 30th 1.7 −1.3 −2.8 23rd
Low Head 12.7 −0.4 14.7 7th 6.1 −1.0 2.3 17th 64.0 70.5 average 91%
Luncheon Hill 10.3 −1.1 16.3 28th 3.9 −1.2 −1.3 22nd 143.4 186.7 low 77%
Marrawah 12.2 −0.5 14.8 31st 6.3 −0.6 2.3 22nd 159.4 128.5 high 124%
Powranna 12.5 −0.1 16.0 30th 0.6 −2.4 −3.5 23rd 27.2 60.4 low 45%
Scottsdale 12.3 −0.3 14.7 30th 2.5 −1.3 −2.4 13th 82.8 118.1 low 70%
Sheffield School Farm 11.1 −0.6 14.3 27th 2.9 −1.0 −2.1 22nd 87.6
Smithton Aerodrome 13.1 −0.6 15.9 30th 4.2 −1.1 −1.9 18th 87.2 104.8 low 83%
Wynyard Airport 13.2 0.0 16.6 27th 3.5 −0.4 −1.1 23rd 113.8 108.7 average 105%
East Coast (district 92)
Bicheno 14.3 −0.3 18.9 31st 5.5 −0.8 3.4 22nd 64.8 49.8 high 130%
Eddystone Point 14.4 +0.9 17.1 29th 6.3 −0.8 2.2 13th 39.4 71.3 low 55%
Fingal 12.9 −0.4 16.7 28th −0.1 −1.1 −5.6 23rd 10.4 58.1 very low 18%
Friendly Beaches 13.8 −1.0 18.6 31st 4.8 −1.4 1.3 22nd 47.8
Lake Leake 9.3 −0.2 13.4 28th −1.3 −1.9 −5.8 25th 21.6 75.9 very low 28%
Maria Island 12.8   16.9 19th 6.6   3.1 13th 28.4
Orford 13.4 −0.6 17.5 19th 3.8 −0.3 0.5 25th 48.4 59.9 average 81%
Scamander 13.7 −1.1 17.6 31st 4.4 −0.7 −0.2 13th 24.6 56.1 low 44%
St Helens Aerodrome 13.5   16.0 31st 3.8   0.0 13th 22.2
Swan Island 13.1   15.3 30th 7.2   3.5 23rd 64.2
Swansea Post Office 13.7 −0.5 19.5 31st 3.4 −1.0 0.2 22nd 22.6 43.6 average 52%
Midlands (district 93)
Ross 12.5 −0.1 18.1 30th 0.8 −1.3 −4.3 22nd 14.0 43.9 low 32%
Southeast (district 94)
Bull Bay 12.5 −0.9 18.0 31st 5.0 −1.0 0.2 13th 61.0 57.6 average 106%
Campania 13.6   18.5 31st 3.0   −1.9 10th 27.2
Cape Bruny 12.3 −0.5 16.9 31st 5.9 −0.8 2.1 13th 76.8 92.8 low 83%
Cape Bruny Lighthouse 11.8 −0.1 16.0 31st 6.1 −0.2 3.3 11th 102.4 93.0 high 110%
Dover 12.6 −0.5 17.0 31st 2.2 −1.8 −1.5 11th 87.4 89.0 average 98%
Geeveston 12.6 −0.3 17.0 30th 1.5 −1.3 −2.9 10th 82.2 99.5 average 83%
Grove 13.1 0.0 17.5 30th 1.2 −1.5 −2.7 11th 65.0 76.7 average 85%
Grove 12.8   17.5 30th 0.6   −3.4 10th 68.2
Hobart 13.7 +0.7 19.5 31st 4.6 −0.6 1.2 18th 39.0 52.8 average 74%
Hobart Airport 13.4 0.0 19.0 31st 4.0 −0.7 1.0 10th 25.8 46.4 low 56%
Maatsuyker Island Lighthouse 10.6 −0.6 16.8 30th 6.6 +0.2 1.0 13th 115.2 123.5 average 93%
Melton Mowbray 12.0 −0.7 16.6 30th 1.5 −1.0 −3.4 22nd 12.2 45.7 very low 27%
Mount Wellington 2.2 −0.5 6.2 5th −2.3 −0.5 −7.5 13th
Tasman Island 10.7   14.7 31st 5.9   0.4 13th 93.2
Tunnack Fire Station 10.4 −0.3 15.3 31st 0.7 −1.4 −3.9 22nd 20.4 54.2 low 38%
Derwent Valley (district 95)
Bushy Park 13.4 +0.4 16.5 19th 0.2 −2.1 −3.7 11th 35.2 53.4 average 66%
Maydena Post Office 11.1 −1.0 15.2 28th 1.5 −1.0 −3.2 22nd 98.4 148.5 low 66%
Ouse Fire Station 13.1 −0.7 17.0 31st 0.9 −1.0 −3.9 22nd 30.8 56.7 low 54%
Tarraleah Village 8.8 −0.7 13.1 28th 0.6 −0.2 −3.1 22nd 113.8 123.6 average 92%
Central Plateau (district 96)
Butlers Gorge 7.8 −0.1 13.4 28th −0.5 −0.4 −6.6 22nd 153.4 177.3 average 87%
Lake St Clair National Park 7.6 −0.6 13.4 28th −0.8 −0.9 −6.5 22nd 183.5 238.6 low 77%
Liawenee 5.9   11.1 28th −2.9   −7.9 22nd 55.8
West Coast (district 97)
Hartz Mountain 6.1 −0.7 12.1 28th 0.7 −0.9 −3.6 13th
Mount Read 2.7 −1.5 7.8 28th −0.6 −0.8 −4.9 22nd
Scotts Peak Dam 9.9 −0.5 17.1 30th 2.9 −0.6 −0.6 13th 198.4
Strahan Aerodrome 12.4 −0.7 18.0 30th 4.7 −1.1 −1.2 22nd 128.8 168.4 low 76%
Strathgordon Village 9.3 −0.6 15.8 30th 2.9 −0.6 0.0 10th 219.8 286.8 low 77%
Warra 8.9   13.6 30th 2.0   −2.3 22nd 172.2
King Island (district 98)
King Island Airport 13.1 −0.5 15.3 4th 7.1 −0.6 2.8 23rd 141.6 114.3 average 124%
Flinders Island (district 99)
Flinders Island Airport 13.3 −0.4 16.2 30th 5.1 −1.5 −2.1 23rd 36.6 74.0 low 49%
Hogan Island 12.4   14.8 30th 8.3   4.3 13th 38.4
Antarctica and Macquarie Island (district 300)
Macquarie Island 4.8 −0.2 7.0 31st 1.5 0.0 −1.3 22nd 90.0 72.2 high 125%


Notes

This statement has been prepared based on information available at 11 am on Monday 1 September 2008. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

Normals 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 ("normal") 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, normal in decile 4 to 7, high in decile 8 or 9 and very high is in decile 10).
The Fraction of normal shows how much rain has fallen this time as a percentage of the long-term mean.

Further information

Ian Barnes-Keoghan
Meteorologist
Tasmania and Antarctica Climate Services Centre
Bureau of Meteorology
Phone (03) 6221 2043
Email climate.tas@bom.gov.au