Wednesday 1 August 2012 - Monthly Climate Summary for Tasmania - Product code IDCKGC27R0
Tasmania in July 2012: a relatively dry and mild month, despite some cold and wet weather
Despite a cold and wet end to the month, Tasmania in July 2012 was drier than usual and the days were milder than usual.
- Mostly dry weather, but the western highlands still wet
- Not many cold days, and a few mild ones
- Some cold nights
- Generally warmer than July 2011 but cooler than July 2010
Dry weather dominates
Dry days were more common than wet during July 2012. High pressure systems deflected many of the rain-bearing systems away from Tasmania. Almost the entire state had below-average total rain for the month, with some areas well below average and pockets in the southern Midlands and on Flinders Island nudging records. Below Craigbourne Dam (on the Coal River) reported just 7.0 mm, whilst Memana's 10.6 mm and Rotherwood's 9.4 mm were their lowest total July rainfalls on record.
A complex area of low pressure moving in from Victoria brought rain to many areas from the 11th to the 13th. It was followed by a string of cold fronts and troughs up to the 20th. This period saw a few wet days in the north, with some daily totals over 20 mm at a few sites. It also ensured that even in a relatively dry month Mount Read in the western highlands received a total of 363.4 mm. A marked cold outbreak from the 28th brought snow to the highlands but not especially high precipitation totals (more fell after 9 am on the 31st, and will be counted in August's totals).
Not many cold days, and a few mild ones
July is winter, so cold weather is expected in Tasmania. But this July there were less cold days than usual, and a few relatively mild days. Temperatures over 17 °C were reported on several occasions: the mildest day was at Friendly Beaches with 17.4 °C on the 17th, but Campania reached 17.1 °C on the 12th, as did Eddystone Point with on the 20th, and Hobart reached 17.0 °C on the 6th.
There were some cold days, especially early and late in the month: Ouse stayed below 8 °C from the 7th to the 10th, and Mount Wellington only reached -1.7 °C on the 29th.
Some cold nights
With high pressure systems close to the state ensuring clear skies and light winds, some low overnight temperatures were inevitable. This was especially true from the 1st to the 9th, and from the 19th to the 24th. The coldest nights were at Butlers Gorge with -6.7 °C on the 8th, followed by Liawenee with -6.6 °C on the 24th. Flinders Island Airport dipped below 3.5 °C every night from the 2nd to the 9th, their longest recorded run of July nights that cold.
There were some relatively mild nights, especially from the 10th to the 18th; Flinders Island Airport's minimum on the 17th was 12.5 °C.
Overall, overnight temperatures were within half a degree of average at most sites. It was a little cooler than average in some areas, but slightly above average at several sites (especially on the West Coast). As with daytime temperatures, it was generally warmer than July 2011, but cooler than July 2010
Hobart: mild and dry weather predominates
The month ended cold and wet for Hobart, but relatively mild and dry weather predominated through July.
There were three days over 16 °C (17.0 °C on the 6th, 16.5 °C on the 12th and 16.4 °C on the 17th), but the 9.2 °C on the 29th was the only day less than 10 °C. In a typical July, Hobart has only one day over 16 °C and seven days less than 10 °C. The maximum temperature averaged across the month was 12.9 °C, which is 1.2 °C above the long-term average and more typical of the mean for August.
There were several below-average nights (dipping down to 1.1 °C on the morning of the 8th and 1.7 °C on the 9th), but these were balanced out by some mild ones (notably 8.9 °C on the 13th and 9.1 °C on the 17th). Hobart's average daily minimum temperature for the month was 4.7 °C , just 0.1 °C above the long-term average.
Hobart's rainfall for the month added up to 18.2 mm, which is just 35% of the long-term average of 51.8 mm. By comparison, last July the city received 50.2 mm, but in 2010 it had only 7.4 mm. Much of the rain came around the 16th (when wind gusts to 74 km/h were also reported), or in the last few days of the month (and continued into August).
The year to date
With a very wet May in many parts of the state, rainfall totals over the last three months were above average. Totals for the first 7 months of 2012 are close to average: wetter than usual in some areas (notably the far southeast), but drier than usual in a few pockets. Daytime temperatures have been slightly above normal, with overnight temperatures much warmer than usual, especially around the southeast and the Derwent Valley.
|Extremes in July 2012|
|Hottest day||17.4 °C at Friendly Beaches on the 17th|
|Warmest days on average||14.3 °C at Eddystone Point|
|Coolest days on average||3.2 °C at Mount Wellington|
|Coldest day||-1.7 °C at Mount Wellington on the 29th|
|Coldest night||-6.7 °C at Butlers Gorge on the 8th|
|Coolest nights on average||-1.6 °C at Liawenee|
|Warmest nights on average||8.7 °C at Cape Grim|
|Warmest night||12.5 °C at Flinders Island Airport on the 17th|
|Warmest on average overall||10.8 °C at Swan Island|
|Coolest on average overall||1.2 °C at Mount Wellington|
|Wettest overall||363.4 mm at Mount Read|
|Driest overall||7.0 mm at Below Craigbourne Dam (Coal River)|
|Wettest day||51.2 mm at Mount Read on the 20th|
|Highest wind gust||131 km/h at Maatsuyker Island Lighthouse on the 15th|
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|Record lowest total July rainfall|
for July 2012 (mm)
|Memana (Babel Farm)||10.6||21.8||in 1976||49||78.9|
|Lowest total July rainfall for at least 20 years|
for July 2012 (mm)
Most recent July
at least this dry
|Waddamana Field Study Centre||21.2||18.8||in 1957*||52||77.6|
|York Plains (Handroyd)||14.8||11.5||in 1971||41||46.2|
|Devonport Airport||35.8||30.0||in 1977*||34||94.4|
|Latrobe (Coal Road)||43.8||40.4||in 1977*||34||121.5|
* note: there are gaps in the historical record at this site, so it is possible a lower value has gone unreported.
|Summary statistics for July 2012|
|Northern (district 91)|
|Bridport (Sea View Villas)||13.4||+0.2||15.5||20th||5.3||-0.1||1.3||29th|
|Cape Grim BAPS (Comparison)||12.8||+0.3||14.9||13th||8.6||+0.4||5.5||31st||98.8||102.1||average||97%|
|Cressy Research Station||11.6||-0.2||14.6||13th||1.7||+0.2||-3.3||4th||30.6||56.5||v low||54%|
|Devonport Airport||13.0||+0.3||14.9||28th||4.2||-0.4||-0.4||30th||35.8||94.4||v low||38%|
|Launceston (Ti Tree Bend)||12.9||+0.3||16.0||6th||2.5||+0.3||-2.3||4th||37.2||74.4||v low||50%|
|Luncheon Hill (Forestry)||10.8||+0.2||13.8||22nd||5.1||+0.2||1.0||31st||142.4||182.6||low||78%|
|Scottsdale (West Minstone Road)||12.1||+0.1||14.7||13th||3.6||-0.1||-0.1||4th||63.4||116.1||low||55%|
|Sheffield School Farm||11.7||+0.9||14.6||6th||2.8||-0.5||-0.9||22nd||69.8||114.4||low||61%|
|Smithton Aerodrome||13.4||+0.3||15.3||21st||4.1||-0.5||-0.7||4th||69.4||108.0||v low||64%|
|Wynyard Airport||13.5||+0.9||15.9||6th||2.6||-0.8||-1.8||4th||38.4||129.3||v low||30%|
|East Coast (district 92)|
|Bicheno (Council Depot)||14.2||+0.2||16.5||17th||6.4||+0.3||3.2||8th||15.7||52.2||low||30%|
|Eddystone Point||14.3||+1.2||17.1||20th||6.9||-0.2||2.5||29th||22.4||75.2||v low||30%|
|Fingal (Legge Street)||12.4||+0.3||15.3||21st||0.6||+0.1||-4.0||5th||18.6||55.2||low||34%|
|Lake Leake (Elizabeth River)||8.8||+0.3||11.6||10th||0.1||0.0||-4.5||29th||27.8||77.0||v low||36%|
|Maria Island (Point Lesueur)||12.6||15.4||6th||7.5||4.2||29th||28.2|
|Orford (Aubin Court)||13.0||0.0||16.0||17th||3.5||0.0||-0.6||21st||21.4||56.5||low||38%|
|St Helens Aerodrome||13.7||+0.3||15.8||6th||4.4||-0.4||1.1||19th||15.4||46.2||v low||33%|
|Swan Island||13.5||+0.4||15.5||26th||8.1||-0.2||3.2||29th||14.0||55.5||v low||25%|
|Swansea (Francis Street)||13.4||16.8||6th||3.5||0.0||8th||23.7|
|Midlands (district 93)|
|Ross (The Boulevards)||11.1||-0.1||14.1||13th||1.2||-0.2||-3.8||5th||17.8||38.0||v low||47%|
|Southeast (district 94)|
|Campania (Kincora)||13.4||+0.3||17.1||12th||2.8||-0.4||-1.6||8th||15.6||32.3||v low||48%|
|Cape Bruny (Cape Bruny)||12.0||0.0||14.2||16th||3.6||29th||42.2||72.3||v low||58%|
|Cape Bruny Lighthouse||11.9||+0.7||14.2||16th||6.6||+0.4||3.7||29th||72.3||95.4||average||76%|
|Dunalley (Stroud Point)||12.6||16.7||17th||5.6||2.8||21st||24.4|
|Geeveston (Cemetery Road)||12.3||+0.3||15.0||6th||1.9||-0.3||-2.6||8th||48.8||90.7||low||54%|
|Grove (Research Station)||12.2||16.3||12th||1.1||-3.5||8th||43.4|
|Hobart (Ellerslie Road)||12.9||+1.2||17.0||6th||4.7||+0.1||1.1||8th||18.2||51.8||v low||35%|
|Maatsuyker Island Lighthouse||11.2||+0.2||15.1||10th||7.7||+1.1||4.3||29th||133.2||128.5||average||104%|
|Melton Mowbray (North Stockman)||11.4||+0.1||15.0||12th||1.0||-1.0||-3.3||23rd||15.2||29.4||low||52%|
|Tunnack Fire Station||9.9||+0.4||13.0||6th||0.7||-0.9||-4.1||23rd||15.2||42.8||v low||36%|
|Derwent Valley (district 95)|
|Bushy Park (Bushy Park Estates)||11.8||+0.7||16.4||12th||1.1||-0.3||-2.4||21st||21.6||49.3||low||44%|
|Maydena Post Office||10.6||0.0||13.8||17th||2.3||+0.1||-0.9||8th||69.2||107.1||low||65%|
|Ouse Fire Station||11.3||-0.3||15.7||21st||0.4||-0.6||-4.8||8th||24.6||46.1||low||53%|
|Tarraleah Village||8.7||+0.4||11.1||21st||0.9||+0.5||-3.1||8th||53.2||115.7||v low||46%|
|Central Plateau (district 96)|
|Lake St Clair National Park||7.4||+0.2||9.7||27th||-0.3||-0.2||-4.6||8th||129.8||202.0||low||64%|
|West Coast (district 97)|
|Hartz Mountain (Keoghs Pimple)||6.2||+0.2||10.4||26th||1.8||+0.4||-1.7||29th|
|Low Rocky Point||12.6||15.5||10th||7.5||5.2||21st||95.8||136.5||low||70%|
|Scotts Peak Dam||9.2||0.0||12.9||24th||3.7||+0.6||0.3||29th||171.8||189.4||low||91%|
|King Island (district 98)|
|King Island Airport||13.3||+0.1||15.0||17th||7.5||0.0||2.8||5th||76.4||111.9||low||68%|
|Flinders Island (district 99)|
|Flinders Island Airport||13.8||+0.5||16.5||12th||5.6||-0.7||-0.9||4th||20.0||82.6||v low||24%|
A Monthly Climate Summary is prepared to list the main features of the weather in Tasmania using the most timely and accurate information available on the date of publication; it will generally not be updated. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review, usually published in the fourth week of the month.
This statement has been prepared based on information available at 9:30 am on Wednesday 1 August 2012. 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
(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.