Monday, 1 June 2009 - Monthly Climate Summary for Tasmania - Product code IDCKGC17R0
Several cold fronts crossed the state in May, delivering over 500 mm of rain to Mount Read. In contrast, several sites in the east received less than 10 mm. Night time temperatures ranged from very cold to very warm, but days were mostly near or slightly warmer than usual until the end of the month.
Wet in the west and dry in the east: A
with several cold fronts ensured that most of the rain in May fell in
the west, and resulted in a stark contrast between the highest rainfall
(over 500 mm at Mount Read) and the lowest (just 6 mm at St Helens).
for some sites in the central east and northeast were
less than 10 mm (although it is not uncommon to have such a dry month
there; similar May totals have typically occurred once
or so years).
The heaviest rain fell with cold fronts on the 14th and 15th. Mount
Read received 140.6 mm in the 24 hours to 9 am on the
highest daily total since records began there in 1996, and 232.2 mm
over the two days, also a record. For
the whole month, it was drier
usual in the east, central north, Bass Strait and on the west coast but
rainfall was near or above average over the remainder.
Some very cold nights, and some very warm: Minimum temperatures during the month varied widely. The coldest temperature was −5.2°C, recorded at Liawenee on the 5th and Lake Leake on the 20th. Several other sites had sub-zero temperatures on these nights and also on the 18th and 19th, with very frosty conditions were reported around Ross and Cressy. In contrast, many overnight temperatures remained in the mid-teens between the 24th and 26th. Minima were up to ten degrees above average and several sites in the north and west had their warmest May night in over ten years. Tarraleah has its warmest May night on record on the 25th, beating the previous record by almost a degree. Mean minima for the month were mostly slightly above average, but were around a degree warmer than usual at a few sites in the Huon Valley and a little below average at a handful of sites.
No extreme daytime temperatures: The last few days of May were quite cold, and there were a few warm days around the 24th, but otherwise most daytime temperatures in May were near average. Mean maxima for the month were near average in the west, south and Bass Strait but half to one degree above average elsewhere. The last four days were below 15°C in Launceston, but these were the only cold days in a city that would normally have about 11 May days below 15°C; this ensured that Launceston had its warmest mean daily maximum for May. Hobart was also mild until the last four days when there were three days below 12°C; before that there were none. The cold conditions were caused by a slow moving high pressure system over the Bight which directed a cold southerly airflow over the state.
Wild and windy between the 14th and 17th: Though most of the weather in May was fairly benign, the period between the 14th and 17th was wild, windy and wet in most areas as a series of active cold fronts crossed the state. The first front crossed in the early hours of the 14th, bringing heavy falls to the western highlands, including around 50 mm to upper parts of the Huon River catchment which led to minor flooding in some parts of the Huon River. More heavy rain fell in the west and south on the following days, with plenty of snow on the 15th and 16th falling to as low as 350 metres. On the 16th swells reached over 6 metres on the south coast as a deep low pressure system crossed waters to the south of Tasmania. It was also very windy for the whole period, but especially so early on the 17th when gusts reached 139 km/h at Droughty Hill and 109 km/h in Hobart, causing extensive damage to trees and houses around Lenah Valley and West Hobart and some power outages. Conditions moderated on the 18th as a high pressure system moved near the state.
|20.6°C at Swansea Post Office on the 8th
|Warmest days on average
Highest mean daily maximum temperature
|17.4°C at Bicheno (Council Depot)|
|Coolest days on average
Lowest mean daily maximum temperature
|5.7°C at Mount Wellington|
Lowest daily maximum temperature
|1.0°C at Mount Wellington on the 30th
|−5.2°C at Liawenee on the 5th and
Lake Leake (Elizabeth River) on the 20th
|Coolest nights on average
Lowest mean daily minimum temperature
|0.9°C at Liawenee|
|Warmest nights on average
Highest mean daily minimum temperature
|11.6°C at Hogan Island|
Highest daily minimum temperature
|15.9°C at Bicheno (Council Depot) on the 26th
Highest total rainfall
|528.8 mm at Mount Read
Lowest total rainfall
|6.0 mm at St Helens Aerodrome|
Highest daily rainfall
|140.6 mm at Mount Read on the 15th
|Highest wind gust
||139 km/h at Cape Grim BAPS on the 16th
|Record highest May mean daily maximum temperature|
Mean daily maximum
for May 2009 (°C)
|Launceston (Ti Tree Bend)||16.8||16.6||in 2007||27||15.8|
|Record highest May daily minimum temperature|
Highest daily minimum
in May 2009 (°C)
|Tarraleah Village||11.9||on the 25th||11.0||on the 2nd in 1997||26||2.4|
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 May 2009|
|Northern (district 91)|
|Cape Grim BAPS||14.5||−0.2||16.8||11th||10.4||+0.2||6.4||29th||48.8||75.4||average||65%|
|Cressy Research Station||15.7||+0.9||19.1||8th||3.2||−0.3||−4.7||18th||21.4||39.2||low||55%|
|Devonport Airport||15.9||+0.6||18.6||23rd||7.7||+0.9||1.1||18th||16.4||74.3||very low||22%|
|Launceston Airport Comparison||14.8||+0.8||17.7||25th||4.6||0.0||−1.4||19th||16.4||60.0||low||27%|
|Low Head||15.5||+0.1||17.8||4th||9.7||+0.2||5.4||18th||10.6||56.6||very low||19%|
|Sheffield School Farm||14.5||+0.9||18.6||8th||5.4||−0.2||0.4||29th||60.0||84.0||low||71%|
|East Coast (district 92)|
|Eddystone Point||17.3||+1.5||19.7||4th||10.2||+0.5||6.4||19th||9.8||66.2||very low||15%|
|St Helens Aerodrome||16.9||20.2||8th||7.8||2.4||19th||6.0|
|Swansea Post Office||16.3||+0.3||20.6||8th||6.2||−0.1||0.2||20th||10.4||46.1||low||23%|
|Midlands (district 93)|
|Southeast (district 94)|
|Cape Bruny Lighthouse||13.6||+0.1||17.3||23rd||8.6||+0.4||3.3||17th||70.6||84.0||average||84%|
|Maatsuyker Island Lighthouse||12.7||−0.1||19.1||23rd||9.1||+0.7||4.2||16th||96.0||115.2||average||83%|
|Tunnack Fire Station||12.3||−0.2||15.7||3rd||4.1||+0.4||−1.2||19th||41.4||39.6||average||105%|
|Derwent Valley (district 95)|
|Maydena Post Office||13.0||−0.1||17.6||23rd||5.4||+1.1||−0.7||1st||107.4||96.3||average||112%|
|Ouse Fire Station||14.5||−0.5||18.7||23rd||4.3||+0.5||−1.7||20th||37.8||32.0||high||118%|
|Central Plateau (district 96)|
|Lake St Clair National Park||10.2||−0.2||14.4||21st||2.0||+0.4||−3.8||19th||179.2||167.7||average||107%|
|West Coast (district 97)|
|Scotts Peak Dam||11.7||+0.2||18.0||23rd||5.6||0.0||2.0||19th||161.6|
|King Island (district 98)|
|King Island Airport||15.6||0.0||17.3||24th||9.7||+0.4||3.2||5th||36.0||85.1||very low||42%|
|Flinders Island (district 99)|
|Flinders Island Airport||16.3||+0.1||19.1||21st||8.8||−0.2||−0.1||19th||26.0||79.5||very low||33%|
|Antarctica and Macquarie Island (district 300)|
This statement has been prepared based on information available at 9 am on Monday 1 June 2009. 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
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.