Monday, 5 January 2009 - Monthly Climate Summary for Tasmania - Product code IDCKGC17R0

Tasmania in December 2008: A cool end to the year

It was cool end to the year with most temperatures in December cooler than normal and only a few warm days. Nights were also cold, especially near the start of the month when Liawenee dropped to −4.5°C, the third coldest December temperature for Tasmania. A low pressure system on the 13th brought flooding rain to the northeast and led to above average rainfall there and in the northwest, but rainfall for the rest of the state was mostly near average.

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

Few warm days: It was a cool start to summer with temperatures for the first three weeks generally below average and struggling to reach into the low 20s. There were even snowfalls on the higher peaks for a number of days in the first week. The coldest days were behind cold fronts on the 1st to 3rd and 10th, and in easterly winds with cloud and rain on the 13th. It finally warmed up on the 21st and 22nd as a northerly pattern developed. Temperatures reached into the low 30s in the southeast on the 22nd, and this combined with very strong winds gusting over 100 km/h to produce some extreme fire dangers. The following week was mild, but a series of cold fronts on the final three days saw a return to cooler conditions with highland snow. Average daytime temperatures for the month were mostly 1 to 2 degrees below normal, and most places had their coolest December since 2001.

Cool nights too: There were several cold nights in the first half of the month, especially on the 4th and 10th when light winds and a cold, clear airmass allowed temperatures to drop below 2°C across much of the state. On these mornings, temperatures were up to 10 degrees below average and several sites had their coldest December night in over 10 years. Liawenee fell to −4.5°C early on the 10th, the third coldest December temperature recorded in Tasmania and the coldest since 1969. Overnight temperatures were milder in the last part of the month, but mean minima for December were still around a degree below normal. Many locations had their coolest December nights since 1996 or 2001.

Flooding in the northeast: A low pressure system to the northwest of Tasmania on the 12th intensified as it moved near Flinders Island on the 13th and brought rainfalls in excess of 80 mm to many sites in the northeast. St Marys was the wettest location, receiving 173 mm over 2 days, including 103 mm in the 24 hours to 9am on the 14th. The rain caused moderate flooding of the South Esk River at Fingal and flooding of several buildings on Flinders Island. Wind gusts reached 113 km/h at Swan Island, but Flinders Island bore the brunt of the strong and gusty southeasterly winds which accompanied the low, and significant damage was reported.

Rainfall mostly around average: Apart from a few sites in the southeast, rainfall for December was average or above. The rain event on the 13th led to wetter than normal conditions in the northeast and northwest, and a series of thunderstorms on the 9th, 16th, 18th and 20th pushed totals above average for a few sites in the lower east. Many sites in the east had their wettest December since 1993 or 1995. Most of the rainfall in the west came from a series of cold fronts near the start and end of the month, each of which saw falls in the order of 15 to 25 mm. These fronts were not strong enough to bring much rainfall to the southeast, and a number of sites there had below average rainfall. Hobart Airport and Ross were the driest locations in the state, receiving only 25.6 mm for the month.

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
31.0°C at Dover and Geeveston on the 22nd
Warmest days on average
Highest mean daily maximum temperature
21.7°C at Bushy Park (Bushy Park Estates)
Coolest days on average
Lowest mean daily maximum temperature
9.4°C at Mount Read
Coldest day
Lowest daily maximum temperature
3.6°C at Mount Read on the 7th
Coldest night
Lowest temperature
−4.5°C at Liawenee on the 10th
Coolest nights on average
Lowest mean daily minimum temperature
1.0°C at Mount Wellington
Warmest nights on average
Highest mean daily minimum temperature
12.1°C at Swan Island
Warmest night
Highest daily minimum temperature
16.2°C at Hobart (Ellerslie Road) on the 23rd
Wettest overall
Highest total rainfall
355.6 mm at Mount Read
Driest overall
Lowest total rainfall
25.6 mm at Hobart Airport and Ross
Wettest day
Highest daily rainfall
102.6 mm at St Marys (Clive Street) on the 14th
Highest wind gust
128 km/h at Mount Wellington on the 22nd

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 December 2008
Maximum temperatures
for December
(°C)
Minimum temperatures
for December
(°C)
Rainfall
for December
(millimetres)
Mean for
December
2008
Diff
from
average
Highest for
December
2008
Mean for
December
2008
Diff
from
average
Lowest for
December
2008
Total for
December
2008
Average
for
December
Rank of
December
2008
Fraction of
December
average
Northern (district 91)
Bridport 18.5 −1.7 22.6 23rd 10.1 −1.1 4.5 4th 79.1 42.4 very high 187%
Burnie 18.7 −0.7 24.0 27th 10.8 −0.2 5.5 10th 59.4 65.0 average 91%
Cape Grim BAPS 16.0 −1.2 20.6 22nd 10.9 −1.0 8.4 10th 83.4 44.5 very high 187%
Cressy Research Station 21.0 27.8 23rd 7.0 −2.2 4th 51.6
Devonport Airport 18.8 −0.7 23.7 27th 9.3 −1.2 2.1 10th 46.4 53.4 average 87%
Launceston 20.8 −1.6 27.7 23rd 9.6 −1.1 2.2 4th 50.0 46.1 average 108%
Launceston Airport 20.3 26.6 22nd 7.6 0.8 4th 44.6
Launceston Airport Comparison 19.7 −1.5 26.0 22nd 8.1 −0.7 1.6 4th 51.8 50.7 average 102%
Low Head 17.5 −1.3 21.0 27th 11.7 −1.1 8.4 11th 49.2 44.6 average 110%
Luncheon Hill 14.8 −3.7 20.8 21st 5.8 −2.8 1.0 10th 122.4 94.3 high 130%
Marrawah 16.9 −1.4 22.0 22nd 9.8 −0.7 6.2 10th 87.8 64.6 high 136%
Scottsdale 18.7 −2.1 24.3 22nd 8.0 −1.1 0.8 4th 83.6 68.2 high 123%
Sheffield School Farm 17.7 −1.9 23.7 27th 7.1 −2.0 1.2 4th 61.6 61.7 average 100%
Smithton Aerodrome 18.2 −1.2 22.3 14th 8.6 −1.1 1.1 10th 118.6 63.2 very high 188%
Wynyard Airport 19.1 −0.3 24.5 27th 8.3 −1.2 1.5 4th 62.2 64.2 average 97%
East Coast (district 92)
Bicheno 19.6 −0.3 26.2 28th 11.1 −0.3 6.0 10th 73.0 68.7 average 106%
Eddystone Point 19.6 +0.3 25.5 27th 11.3 −1.0 6.1 4th 107.6 60.2 high 179%
Fingal 19.5 −2.0 26.6 27th 7.9 −0.8 0.4 4th 71.2 49.8 high 143%
Friendly Beaches 20.3 −1.6 24.9 6th 10.6 −1.2 5.5 10th
Lake Leake 16.4 −1.2 24.8 22nd 5.4 −1.6 −2.7 4th 71.0 73.1 average 97%
Maria Island 19.0 25.8 28th 11.1 7.3 4th 71.6
Orford 19.6 −0.8 29.2 22nd 9.7 −0.9 5.4 10th 75.2 63.9 high 118%
Scamander 19.3 −1.0 27.3 27th 10.6 −0.7 6.1 4th 117.2 62.4 high 188%
St Helens Aerodrome 19.7 26.1 27th 10.6 4.3 4th 140.8
Swan Island 18.2 23.2 22nd 12.1 7.6 4th 89.4
Swansea Post Office 20.1 −0.6 29.4 22nd 9.4 −1.1 3.7 10th 66.2 59.9 average 111%
Midlands (district 93)
Ross 21.0 −1.7 28.4 22nd 7.7 −0.8 −0.6 4th 29.4 37.8 average 78%
Southeast (district 94)
Bull Bay 18.9 −0.9 29.7 22nd 9.7 −0.9 5.5 4th 30.0 63.4 low 47%
Campania 21.1 30.5 22nd 8.9 2.6 10th 36.8
Cape Bruny 17.4 −0.8 30.9 22nd 9.5 −1.2 6.5 4th 32.0 61.3 very low 52%
Cape Bruny Lighthouse 16.6 −0.3 29.9 22nd 9.7 −0.7 7.0 4th 44.8 76.9 low 58%
Dover 18.4 −0.6 31.0 22nd 7.8 −1.2 2.6 4th
Geeveston 18.9 −1.0 31.0 22nd 8.2 −0.5 2.0 10th 54.6 73.0 average 75%
Grove 19.5 −0.7 30.5 22nd 7.8 −0.8 1.1 4th 63.0 62.9 average 100%
Grove 19.6 30.4 22nd 7.1 0.3 4th 72.6
Hobart 20.2 −0.2 29.9 22nd 10.2 −0.6 5.0 4th 38.6 56.9 average 68%
Hobart Airport 20.2 −0.4 30.3 22nd 9.9 −0.8 4.3 10th 25.6 53.6 low 48%
Maatsuyker Island Lighthouse 14.2 −1.5 26.9 22nd 8.7 −0.8 5.4 2nd 66.0 90.4 average 73%
Melton Mowbray 20.0 −2.0 28.9 22nd 8.0 −1.1 1.0 10th 29.6 37.8 average 78%
Mount Wellington 9.8 −1.2 18.8 22nd 1.0 −1.8 −3.6 4th 121.0 88.6 high 137%
Tasman Island 15.5 23.0 28th 9.2 6.5 4th 43.8
Tunnack Fire Station 17.8 −1.9 24.4 27th 6.4 −1.1 −1.0 4th 75.8 52.0 high 146%
Derwent Valley (district 95)
Bushy Park 21.7 −0.3 30.9 22nd 8.4 −0.7 1.1 10th 28.8 50.8 low 57%
Maydena Post Office 17.6 −2.2 28.2 22nd 7.2 −0.2 1.6 10th 97.5 89.6 average 109%
Ouse Fire Station 21.0 −2.1 30.3 21st 7.9 −0.7 1.4 10th 33.6 37.1 average 91%
Tarraleah Village 15.9 −1.9 25.4 21st 5.5 −0.6 −0.4 10th 94.6 91.9 average 103%
Central Plateau (district 96)
Butlers Gorge 14.7 −1.9 24.3 21st 4.7 −0.8 −1.1 10th 143.4 127.5 average 112%
Lake St Clair National Park 15.0 −2.4 24.8 21st 4.2 −0.9 −1.0 10th 139.4 134.6 average 104%
Liawenee 14.0 21.3 21st 2.5 −4.5 10th 39.4
West Coast (district 97)
Hartz Mountain 13.1 −1.8 25.4 22nd 3.7 −1.5 −0.1 10th 101.0 81.0 high 125%
Mount Read 9.4 −2.4 20.2 21st 2.6 −1.3 −1.6 10th 355.6 298.2 high 119%
Scotts Peak Dam 17.1 −1.3 28.6 22nd 6.5 −1.5 2.7 10th
151.3
Strahan Aerodrome 17.7 −2.1 28.0 22nd 8.8 −0.8 4.4 10th 93.6
Strathgordon Village 15.8 −1.4 27.0 22nd 7.7 −0.6 3.0 4th 219.5 201.2 average 109%
Warra 15.5 27.7 22nd 5.8 1.1 10th 137.8
King Island (district 98)
King Island Airport 17.4 −1.2 26.3 22nd 10.2 −0.7 2.8 11th 63.6 50.9 high 125%
Flinders Island (district 99)
Flinders Island Airport 18.8 −1.3 25.5 5th 11.3 −0.4 4.5 11th 134.4 58.0 very high 232%
Antarctica and Macquarie Island (district 300)
Macquarie Island 7.6 −0.3 9.3 29th 4.1 −0.1 0.7 5th 81.2 77.3 average 105%


Notes

This statement has been prepared based on information available at 9 am on Monday 5 January 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 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

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