Monday, 1 September 2008 - Monthly Climate Summary for Tasmania - Product code IDCKGC17R0
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.
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.
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|
Lowest daily maximum temperature
−2.4°C at Mount Wellington on the 15th|
−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|
Highest daily minimum temperature
12.3°C at Flinders Island Airport on the 31st|
Highest total rainfall
|259.2 mm at Lake Margaret Power Station|
Lowest total rainfall
|9.4 mm at Mount Morriston (Macquarie River)|
Highest daily rainfall
69.0 mm at Warra on the 14th|
|Highest wind gust||
144 km/h at Mount Wellington on the 19th|
|Lowest total August rainfall for at least 20 years|
for August 2008 (mm)
|Most recent lower
|Lake Leake (Elizabeth River)||21.6||8.0||in 1982||26||75.9|
|Oatlands Post Office||11.2||6.0||in 1982||25||44.7|
|Record lowest August mean daily minimum temperature|
|Mean daily minimum|
for August 2008 (°C)
|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|
for August 2008 (°C)
|Most recent lower
|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|
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|
|Northern (district 91)|
|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%|
|Launceston Airport Comparison||11.9||−0.1||15.7||30th||1.7||−1.3||−2.8||23rd|
|Sheffield School Farm||11.1||−0.6||14.3||27th||2.9||−1.0||−2.1||22nd||87.6|
|East Coast (district 92)|
|Lake Leake||9.3||−0.2||13.4||28th||−1.3||−1.9||−5.8||25th||21.6||75.9||very low||28%|
|St Helens Aerodrome||13.5||16.0||31st||3.8||0.0||13th||22.2|
|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)|
|Southeast (district 94)|
|Cape Bruny Lighthouse||11.8||−0.1||16.0||31st||6.1||−0.2||3.3||11th||102.4||93.0||high||110%|
|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%|
|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)|
|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%|
|Central Plateau (district 96)|
|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%|
|West Coast (district 97)|
|Scotts Peak Dam||9.9||−0.5||17.1||30th||2.9||−0.6||−0.6||13th||198.4|
|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%|
|Antarctica and Macquarie Island (district 300)|
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
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
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.