Sunday, 1 September 2013 - Monthly Climate Summary for Tasmania - Product code IDCKGC27R0
August rainfall was well above average across most of Tasmania, and record wet in some parts of the north. Frequent rain throughout the month led to flooding in the north when falls were heavy. Maximum temperatures were close to average. Minimum temperatures were up to 2 °C above average in the north, and up to 1 °C elsewhere.
A summary for all of winter has also been prepared.
August saw the passage of cold fronts and low pressure troughs on most days, and in combination with warmer than usual sea surface temperatures surrounding Tasmania led to frequent rain across the north and west of the state. The rain was heavy at times, notably around the 6th, 14th and 19th, which resulted in flooding as catchments were already saturated. The flooding caused damage to property, landslips and a rock falls. Several roads were closed across the north of the state, with railway lines also affected.
On the evening of the 5th, a short but intense heavy rain event produced daily totals of around 20 to 60 mm across the north and west. Three Hummock Island recorded 36 mm, its highest August daily rainfall on record. The rainfall caused minor flooding in the Meander, Mersey, North Esk, upper South Esk and lower Macquarie river basins, as well as minor flash flooding in the Railton area.
A cold front brought heavy rain to the north and west overnight on the 13th. Daily rainfall totals generally ranged from 30 to 60 mm, peaking at 78 mm at Mount Victoria. Cape Grim BAPS recorded its wettest August day on record with 39.4 mm. There was moderate flooding in the North Esk, Lower Meander and Upper South Esk river basins, and minor flooding in the Mersey and Forth rivers with this event. The heavy rain caused flash flooding around Launceston (Launceston recorded 52 mm over the 24 hours to 9am on the 14th), and in Smithton.
Another cold front crossed overnight on the 16th, followed by a second during the day on the 18th. Daily rainfall totals of around 20 to 40 mm were observed across the north and west on each of those three days. Mount Victoria recorded the highest daily total with 87 mm over the 24 hours to 9am on the 19th. There was moderate flooding in the North Esk, Mersey, Lower Meander, Lower Macquarie, and Upper South Esk river basins, and minor flooding in the Forth river basins. The Launceston area also flooded for a second time in a week.
August rainfall totals were two to three times the long-term average across northern Tasmania. Sites including Launceston, Scottsdale, Marrawah and Wynyard all had their highest total August rainfall on record, with several other sites observing their wettest August in more than 20 years. Launceston's 233.0 mm is its highest total for any month. This beats the previous monthly record of 183.6 mm set at the current Ti Tree site in August 2005, but is around 35 mm short of the all-time record set at the Launceston City site in August 1936 (254.4 mm).
It rained on almost every day in August across the north and west, with only a handful of rain-free days. Daily rainfall amounts were not as high in the east, resulting in near-average August rainfall totals in the east compared to well-above-average totals elsewhere. Across Tasmania, more than 20 dams were spilling in August due to the above-average rain.
Mount Read was the wettest site overall with at least 740.6 mm (the true total is not known as snow was blown away on some days), whilst Swansea on the east coast was the driest with 21.0 mm.
A series of cold fronts brought snow showers and strong winds between the 18th and 21st. The cold front on the 18th produced damaging winds across the north, with wind gusts reaching 83 km/h in Launceston, 93 km/h in Wynyard and 98 km/h in Devonport. Cape Grim recorded a wind gust of 157 km/h that evening, followed by a wind gust of 161 km/h in the early hours of the 19th. Thousands of premises lost power in the Launceston area due to downed power lines, including South Launceston, Trevallyn, Kings Meadows and Riverside. Hundreds of premises also lost power around Burnie, Boat Harbour, and Pipers River.
Snow settled down to around 400 m on the 20th, resulting in a number of road closures in the northwest. This followed earlier snow showers between the 12th to 14th, with reports of thick snow in the northwest around the 13th which closed the Anthony Road between Tullah and Queenstown.
Maximum temperatures were generally on the cool side of average over the first 3 weeks of August due to increased cloud cover and above-average rainfall. The coldest day was on the 20th when maxima remained below 12 °C in a cold southwesterly flow, and there were reports of snow down to 400 m and small hail. Mount Wellington's maximum of −2.6 °C was the coldest day of the month.
The last 9 days of August were warmer than average, maxima rising into the mid to high teens every day. Most sites had their warmest day of the month on the 30th or 31st, Hobart's 19.7 °C on the 30th the highest temperature observed.
Overall, mean maximum temperatures were within one degree of the August average in most areas.
The morning of the 21st was particularly cold, with temperatures dropping below zero in many areas and approaching −7 °C in central regions. Several sites had their coldest August morning in several years: Burnie's minimum of −1.3 °C was its coldest August morning in 18 years and Launceston's −2.5 °C its coldest August morning in 7 years. Liawenee's −7.6 °C that morning was the lowest temperature of the month.
Nights were warmer than average around the 25th, 26th, 30th and 31st due to milder northwest winds and overnight cloud cover. Devonport equalled its warmest August night on record on the 30th with a minimum of 12 °C. The highest minimum temperature of the month was 12.9 °C at Cape Sorell and Flinders Island Airport on the 30th.
Overall, mean minimum temperatures were warmer than average, by up to 2 °C in the north, and up to 1 °C elsewhere.
Hobart had a few cold nights in August, the coldest of which was on the 21st when the temperature dropped to −0.4 °C. This was Hobart's coldest morning in 18 years (since −1.0 °C on 6 June 1995) and its coldest August morning in 41 years (since −1.8 °C on 5 August 1962). There were also a few mild nights, Hobart's minimum of 10.2 °C on the morning of the 25th was the warmest of the month. Overall, minimum temperatures were 0.5 °C above average.
The temperature rose to 16 degrees or higher on 10 days, more than double the August average of 4 days. The warmest day was 19.7 °C on the 30th. The coldest day was on the 20th when the temperature only reached 9.8 °C. This was the only day the temperature remained below 10 °C; a typical August sees an average of 4 days. Overall, day-time temperatures were 1.1 °C above average for Hobart.
Hobart recorded 61.0 mm of rain, slightly more than the long-term average of 53.6 mm. The wettest day was on the 13th when a cold front delivered 15 mm over the 24 hours to 9am on the 14th.
|Extremes in August 2013|
|Hottest day||19.7 °C at Hobart (Ellerslie Road) on the 30th|
|Warmest days on average||15.4 °C at Bicheno (Council Depot)|
|Coolest days on average||2.8 °C at Mount Wellington|
|Coldest day||-2.6 °C at Mount Wellington on the 20th|
|Coldest night||-7.6 °C at Liawenee on the 21st|
|Coolest nights on average||-2.1 °C at Mount Wellington|
|Warmest nights on average||9.2 °C at King Island Airport|
|Warmest night||12.9 °C at Cape Sorell and at Flinders Island Airport on the 30th|
|Warmest on average overall||11.8 °C at King Island Airport|
|Coolest on average overall||0.4 °C at Mount Wellington|
|Wettest overall||740.6 mm at Mount Read*|
|Driest overall||21.0 mm at Swansea (Francis Street)|
|Wettest day||87.0 mm at Mount Victoria (Una Plain) on the 19th|
|Highest wind gust||161 km/h at Cape Grim BAPS (Comparison) on the 19th|
* The true total at Mount Read is probably higher, as it is likely some snow was lost.
Click on a map to show it full size in a pop-up window
|Record highest August daily rainfall|
Highest daily rainfall
in August 2013 (mm)
|Cape Grim BAPS (Comparison)||39.4||on the 14th||38.8||on the 2nd in 2007||27|
|Three Hummock Island||36.2||on the 6th||35.6||on the 12th in 1947||22|
|Low Rocky Point||43.6||on the 12th||34.0||on the 10th in 2007||20|
|Record highest total August rainfall|
for August 2013 (mm)
|City of Melbourne Bay||350.2||335.4||in 1936||81||140.0|
|Burnie (Round Hill)||253.5||244.0||in 1955||70||112.3|
|Forthside Research Station||245.0||239.0||in 1970||47||119.7|
|Scottsdale (West Minstone Road)||298.6||269.4||in 1991||43||124.6|
|Wynyard Airport||334.6||273.1||in 1955||42||120.5|
|Launceston (Ti Tree Bend)||233.0||183.6||in 2005||34||90.7|
|Cape Grim BAPS (Comparison)||252.0||208.6||in 2009||27||99.3|
|Strahan Aerodrome||329.6||324.6||in 1996||26||179.8|
|Deviot Jetty||255.6||216.2||in 2009||23||108.5|
|Mount Victoria (Una Plain)||554.0||510.4||in 2011||22||278.9|
|Three Hummock Island||275.6||196.0||in 2009||22||128.3|
|Highest total August rainfall for at least 20 years|
for August 2013 (mm)
Most recent August
at least this wet
|Frankford (Rossville)||315.8||337.7||in 1939||74||128.3|
|Latrobe (Coal Road)||291.4||410.0||in 1939*||73||116.9|
|Ringarooma (Charles Street)||379.0||401.2||in 1936*||71||151.7|
|Northdown (Hamley)||211.8||292.6||in 1939*||70||91.0|
|Yolla (Sea View)||368.8||409.5||in 1955||58||183.9|
|Mole Creek||288.2||293.2||in 1970*||42||146.4|
|Barrington Post Office||293.7||319.1||in 1970*||41||146.6|
|Maatsuyker Island Lighthouse||228.2||255.0||in 1991||22||124.1|
|Lilydale Post Office||217.0||236.3||in 1991*||21||114.8|
* note: there are gaps in the historical record at this site, so it is possible a higher value has gone unreported.
|Record highest August daily minimum temperature|
Highest daily minimum
in August 2013 (°C)
|Devonport Airport||12.0||on the 30th||= 12.0||on the 30th in 2005||22||5.1|
|Summary statistics for August 2013|
|Northern (district 91)|
|Bridport (Sea View Villas)||13.5||-0.2||16.7||29th||5.2||-0.6||-1.1||21st||232.9||95.8||v high||243%|
|Burnie (Round Hill)||13.6||+0.5||17.3||26th||7.2||+1.1||1.3||21st||253.5||112.3||highest||226%|
|Burnie NTC AWS||13.1||16.0||27th||7.4||2.4||21st|
|Cape Grim BAPS (Comparison)||13.1||+0.4||16.0||31st||8.5||+0.2||4.8||21st||252.0||99.3||highest||254%|
|Cressy Research Station||12.9||-0.1||16.5||26th||3.5||+0.9||-4.1||21st||144.0||76.1||high||189%|
|Launceston (Ti Tree Bend)||14.0||+0.2||17.8||29th||4.5||+0.8||-2.5||21st||233.0||90.7||highest||257%|
|Low Head||13.2||+0.1||16.0||31st||8.3||+0.9||0.5||21st||192.2||89.5||v high||215%|
|Scottsdale (West Minstone Road)||12.2||-0.4||15.7||31st||4.3||+0.4||-2.0||21st||298.6||124.6||highest||240%|
|Sheffield School Farm||11.1||-0.6||14.9||26th||4.0||+0.1||-2.4||21st||309.6||144.7||v high||214%|
|Smithton Aerodrome||13.5||-0.2||16.2||31st||5.9||+0.5||-1.6||21st||286.6||129.2||v high||222%|
|East Coast (district 92)|
|Bicheno (Council Depot)||15.4||+0.7||19.5||30th||6.9||+0.5||2.6||5th||40.5||51.0||average||79%|
|Fingal (Legge Street)||13.3||0.0||17.8||31st||2.0||+0.7||-4.9||21st||85.4||60.6||high||141%|
|Lake Leake (Elizabeth River)||9.6||+0.1||13.9||31st||0.9||+0.1||-6.6||21st||104.4||79.3||high||132%|
|Larapuna (Eddystone Point)||14.3||+0.6||17.3||31st||7.6||+0.4||1.9||21st||95.4||72.1||high||132%|
|Maria Island (Point Lesueur)||13.8||17.3||31st||7.5||3.7||21st||48.4||43.7||average||111%|
|Orford (Aubin Court)||14.3||+0.3||19.4||31st||4.0||-0.2||-2.1||21st||61.2||62.1||average||99%|
|Spring Bay NTC AWS||13.8||17.6||31st||6.4||2.0||5th|
|St Helens Aerodrome||14.5||+0.2||18.1||31st||5.5||+0.1||-0.9||21st|
|Swansea (Francis Street)||15.2||19.4||31st||4.9||-1.1||21st||21.0|
|Midlands (district 93)|
|Ross (The Boulevards)||12.4||-0.2||16.3||25th||3.1||+0.7||-5.4||21st||85.0||50.1||high||170%|
|Southeast (district 94)|
|Bull Bay (Lauriston)||13.7||+0.4||18.0||31st||6.0||0.0||2.5||5th||40.6||56.0||low||73%|
|Cape Bruny (Cape Bruny)||12.8||-0.1||18.1||31st||6.4||-0.3||2.2||21st||99.0||90.7||average||109%|
|Cape Bruny Lighthouse||12.5||+0.6||17.2||31st||6.4||+0.1||2.3||21st||106.0||93.1||high||114%|
|Dunalley (Stroud Point)||13.7||18.8||30th||6.8||1.7||5th||54.0|
|Geeveston (Cemetery Road)||12.9||-0.1||18.0||30th||3.6||+0.6||-2.7||21st||158.4||105.5||high||150%|
|Grove (Research Station)||13.4||18.4||29th||2.7||-4.0||21st||101.8||89.3||average||114%|
|Hobart (Ellerslie Road)||14.2||+1.1||19.7||30th||5.7||+0.5||-0.4||21st||61.0||53.7||high||114%|
|Maatsuyker Island Lighthouse||11.5||+0.3||17.8||31st||6.6||+0.1||3.2||20th||228.2||124.1||v high||184%|
|Melton Mowbray (North Stockman)||12.7||+0.1||17.6||31st||3.2||+0.5||-3.5||5th||59.6||52.3||average||114%|
|Tunnack Fire Station||10.3||-0.3||14.4||31st||1.8||-0.3||-5.2||5th||58.0||65.7||average||88%|
|Derwent Valley (district 95)|
|Bushy Park (Bushy Park Estates)||13.6||+0.5||18.4||31st||2.1||-0.3||-3.8||21st|
|Maydena Post Office||10.8||-1.2||16.3||31st||2.6||-0.1||-3.1||21st||244.0||157.2||v high||155%|
|Ouse Fire Station||13.0||-0.7||18.8||31st||2.3||+0.1||-3.0||21st||93.2||64.1||average||145%|
|Central Plateau (district 96)|
|Butlers Gorge||7.8||-0.1||13.5||31st||0.3||+0.2||-6.6||21st||377.8||185.3||v high||204%|
|Lake St Clair National Park||7.6||-0.6||13.7||31st||0.3||0.0||-6.6||21st|
|West Coast (district 97)|
|Hartz Mountain (Keoghs Pimple)||5.5||-1.2||11.3||29th||0.5||-1.0||-2.8||21st|
|Low Rocky Point||12.8||18.3||31st||6.8||2.6||21st||231.2||153.8||v high||150%|
|Scotts Peak Dam||9.8||-0.6||15.7||29th||3.0||-0.6||0.0||20th||379.4||224.3||v high||169%|
|King Island (district 98)|
|King Island Airport||14.2||+0.5||19.6||31st||9.2||+1.4||3.9||21st|
|Flinders Island (district 99)|
|Flinders Island Airport||14.4||+0.6||17.8||31st||8.3||+1.7||-1.6||21st||152.2||77.6||v high||196%|
|Antarctica and Macquarie Island (district 300)|
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 11 am on Sunday 1 September 2013. 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.
The ACORN-SAT dataset is being used for temperature area averages from December 2012 onwards. The major change from earlier datasets is that the ACORN-SAT dataset commences in 1910, rather than 1950, and hence rankings are calculated using a larger set of years.