Northern Territory in August 2012: Cold start with a warm end

The first signs of transition from the dry season were evident in August. Early in the month, a typical dry season synoptic pattern brought cold, dry air across the Northern Territory. Indicative of this were several stations recording record low temperatures. Later in the month, increased temperatures across northern Australia encouraged the southern pre-frontal troughs to extend further north. These interrupted the sub tropical ridge, a persistent area of high pressure across the southern half of the continent, bringing more humid easterly winds across the Top End and north easterlies to the Alice Springs district. Morning fogs were present along the Top End coasts and valleys on 7 days, while the hotter winds kept minimum temperatures higher in the Alice. The sub tropical ridge was still the major influence, bringing fresh and dry southeasterly winds across the Top End.

  • Darwin Airport records lowest August temperature in 22 years
  • Alice Springs' second longest dry spell on record
  • Bradshaw sets new record for lowest August temperature

Darwin experiences a change

The transition out of the dry season can bring some very interesting weather, particularly the effect on temperatures. Early in the month, a typical dry season synoptic pattern still influenced the weather and cooler, dry southeasterly winds allowed Darwin airport to record the lowest ever August temperature of 13.1C on the 13th. The previous record of 13.2C on the 2 August 1990 had stood for 22 years. Toward the end of the month warmer temperatures returned to northern Australia. Darwin airport recorded 35.6C on the 27th, the hottest day since 27 November 2011 the previous year.

Top End feels low temperatures

Under the influence of a high pressure system in the south, the 13th and 14th saw new August minimum temperature records across the Top End. On the 13th, Darwin Airport's minimum temperature dropped to 13.1 C. Middle point measured a record 5.0 C also on the 13th. On the 14th Bradshaw dropped to 6.9 C, which broke the old record of 9.0 C set on 3 August 2003.

Morning fogs obscure the previous record at Darwin Airport

The more humid easterly winds brought low level moisture to much of the Top End. This resulted in morning fogs on a record 9 days in August, beating the previous number of 7 days back in 2004. The average number of days for fog in August is 1.9 days.

Record dry in southern NT

A strong sub tropical ridge, especially a persistent area of high pressure over southern WA, maintained very dry conditions across the Territory all winter which persisted throughout August. Alice Springs, Yulara, Territory Grape Farm, and Walungurru did not record any rainfall this month and have tied 2002 as the driest winter (June-August) on record.

Alice Springs Airport has not record any rainfall since 24 April this year. This is the second longest dry spell at Alice Springs Airport with 129 days so far this year (to 31 August). The record longest dry spell was in 1972 when no rain was recorded as Alice Springs Airport for 147 days.

Rainfall

Throughout most of August, the strong sub tropical ridge maintained cool and dry conditions across the Territory. Easterly winds brought shallow moisture across the Top End, which resulted in a few isolated showers. The same high pressure systems blocked cold fronts from reaching the Alice Springs district. Stations which would usually record 5 to 10 mm during August were left dry this month. The wettest overall was 12.2 mm at Conways, followed by North East Island with 5.0 mm, and then Gove Airport with 2.0 mm. The wettest single days were all at Conways with 6.0 mm on the 19th, followed by 2.6 mm on the 20th, 1.6mm falling on the 3rd and on the 10th.

Temperature

When averaged across the Territory the mean temperature for the NT this month was 19.89 °C which was 0.31 °C below average.

The warmest on average was Cape Don with 26.2 °C, followed by Cape Wessel with 26.0 °C, and then Jabiru Airport with 25.6 °C.

The coolest on average was Arltunga with 13.6 °C, and then Kulgera with 14.5 °C, followed by Alice Springs Airport with 14.6 °C.

Maximum temperature

The mean maximum temperature for August was 28.98 °C which is 1.18 °C above the long term average. Most of the territory was at least one degree above the long term average, except for the Darwin-Daly and Roper river catchment areas which were around one degree cooler than the long term average. Afternoon seabreezes combined with light, moist easterly winds were major mitigating factors which assisted in reducing temperatures along the coast.

The hottest days were at Middle Point with 38.1 °C on the 26th, followed by Noonamah and Middle Point with 38.0 °C on the 26th and 28th respectively, then Bradshaw and Middle Point with 37.9 °C both on the 24th.

The warmest days on average were at Middle Point with 34.5 °C, followed by Noonamah with 34.4 °C, and then Jabiru Airport with 34.0 °C.

The coolest days on average were at Kulgera with 23.3 °C, followed by Arltunga with 23.7 °C, and then Alice Springs Airport with 24.9 °C.

The coldest days in August were all recorded at Arltunga with 16.9 °C on the 11th, 17.0 °C on the 12th, and 17.2 °C on the 18th.

Three sites had their highest August temperature on record, including Pirlangimpi, Batchelor Aero and Middle Point. McCluer Island had their coldest August day (lowest maximum temperature) on record. Channel Point had their lowest August mean daily maximum temperature on record.

Minimum temperature

Cool, dry southeasterly winds were the main contributing factor to the below average minimum temperatures. The mean minimum temperature for August was 10.72 °C which was 1.8 °C below the long term mean minimum. Minimum temperatures were below across the Territory this month. With a mean daily minimum temperature of 17.8 C, Darwin Airport tied with the record lowest August mean daily minimum temperature, a record set in 2002. Middle Point, Mango Farm, and Dum-in-Mirrie also had their lowest August mean daily minimum temperature on record. Five sites had their lowest August temperature on record, including Darwin Airport and Bradshaw.

The coldest nights were at Arltunga with -4.7 °C on the 2nd, -3.7 °C on the 3rd and -3.6 °C on the 13th. Alice Springs Airport also recorded -3.6 °C on the 1st.

The coolest nights on average were at Arltunga with 3.5 °C, followed by Alice Springs Airport with 4.3 °C, and then Yulara Aero with 4.7 °C.

The warmest nights on average were at Cape Wessel with 22.7 °C, followed by McCluer Island with 22.5 °C, and then Cape Don with 22.0 °C.

The warmest night was at McCluer Island with 24.4 °C on the 27th, and then 24.3 °C at Cape Don on the 25th, and Darwin NTC and McCluer Island on the 26th, followed by McCluer Island with 24.1 °C on the 25th.

Wind

Fresh southeastly winds, resulting from a strong sub tropical ridge, dominated the Territory during August. The strongest wind gust was at Darwin NTC with 83 km/h on the 17th, followed by McCluer Island with 69 km/h on the 12th. Darwin NTC also registered 69 km/h on the 18th, Yulara Aero with 69 km/h on the 24th, and then Centre Island with 67 km/h on the 19th.

Further information

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Extremes in August 2012
Hottest day 38.1 °C at Middle Point on the 26th
Warmest days on average 34.4 °C at Middle Point
Coolest days on average 23.3 °C at Kulgera
Coldest day 16.9 °C at Arltunga on the 11th
Coldest night -4.7 °C at Arltunga on the 2nd
Coolest nights on average 3.5 °C at Arltunga
Warmest nights on average 22.7 °C at Cape Wessel
Warmest night 24.4 °C at McCluer Island on the 27th
Warmest on average overall 26.1 °C at Cape Don
Coolest on average overall 13.5 °C at Arltunga
Wettest overall 12.2 mm at Conways
Wettest day 6.0 mm at Conways on the 19th
Highest wind gust 83 km/h at Darwin NTC on the 17th

Maps
Observed Anomaly Decile rank
Total
rainfall
Map of Rainfall totals Map of Percentage of normal rainfall Map of Rainfall deciles
Mean
daily
maximum
temperatures
Map of Mean maximum temperature Map of Anomaly in mean maximum temperature Map of Decile rank of mean maximum temperature
Mean
daily
minimum
temperatures
Map of Mean minimum temperature Map of Anomaly in mean minimum temperature Map of Decile rank of mean minimum temperature

 


Record highest August temperature
Highest temperature
in August 2012 (°C)
Previous warmest
for August
Years of
record
Average for
August
Pirlangimpi 35.6 on the 28th = 35.6 on the 26th in 1998 30 32.0
Batchelor Aero 36.6 on the 26th = 36.6 on the 25th in 2010 16 33.3
Middle Point 38.1 on the 26th 37.5 on the 31st in 2009 12 33.9



Record lowest August daily maximum temperature
Lowest daily maximum
temperature
in August 2012 (°C)
Previous coolest
for August
Years of
record
Average for
August
McCluer Island 24.5 on the 13th 25.0 on the 16th in 1999 12 27.8



Record lowest August mean daily maximum temperature
Mean daily maximum
temperature
for August 2012 (°C)
Previous coolest
for August
Years of
record
Average for
August
Channel Point 28.6 28.7 in 1997 17 29.5



Record lowest August temperature
Lowest temperature
in August 2012 (°C)
Previous coolest
for August
Years of
record
Average for
August
Darwin Airport 13.1 on the 13th 13.2 on the 2nd in 1990 72 20.4
Yuendumu -1.4 on the 6th -1.2 on the 4th in 2003 44 8.5
Bradshaw 6.9 on the 14th 9.0 on the 3rd in 2003 14 16.6
Arltunga -4.7 on the 2nd -4.5 on the 16th in 2002 12 5.2
Middle Point 5.0 on the 13th 7.4 on the 5th in 2006 12 15.1



Record lowest August mean daily minimum temperature
Mean daily minimum
temperature
for August 2012 (°C)
Previous coolest
for August
Years of
record
Average for
August
Darwin Airport 17.8 = 17.8 in 2002 71 20.4
Daly Waters 8.6 9.4 in 2011 42 13.0
Mango Farm 11.5 12.4 in 2002 32 15.9
Elliott 10.0 10.4 in 2002 30 13.3
Lajamanu 8.5 = 8.5 in 2002 17 11.1
Dum In Mirrie 17.2 17.4 in 2002 13 19.3
McCluer Island 22.5 22.7 in 2007 11 23.2
Middle Point 12.3 13.5 in 2002 11 15.1

Summary statistics for August 2012
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean Diff
from
average
Highest Mean Diff
from
average
Lowest Total Average
Rank Fraction of
average
Darwin-Daly (district 14GA)
Batchelor Aero 33.2 -0.1 36.6 26th 14.5 -2.7 9.8 2nd 0.6 2.8 average 21%
Black Point 30.2 -0.3 32.6 25th 20.0 -1.2 17.0 13th 0 1.3 lowest 0%
Bradshaw 33.7 +0.3 37.9 24th 13.7 -2.9 6.9 14th 0 0.1 lowest 0%
Cape Don 30.3   32.0 26th 22.0   19.9 13th 0 1.2 lowest 0%
Central Arnhem Plateau 30.8   34.5 24th 13.8   8.8 13th 0
Channel Point 28.6 -0.9 32.4 20th 16.1 -2.3 11.5 14th 0 4.8 lowest 0%
Darwin Airport 31.4 0.0 35.6 27th 17.8 -2.6 13.1 13th 0 5.0 lowest 0%
Delamere Weapons Range 32.1 +0.5 36.6 26th 14.7 -1.3 9.6 14th 0 0.4 lowest 0%
Douglas River 33.8 +0.3 37.8 24th 11.3 -2.9 5.6 2nd 0 1.4 lowest 0%
Dum In Mirrie 29.8 -0.8 32.6 10th 17.2 -2.1 12.9 1st 0.4 3.5 average 11%
Jabiru Airport 34.0 +0.3 37.4 26th 17.2 -2.0 14.0 13th 0 2.8 lowest 0%
Katherine Country Club 32.8   36.8 24th 11.8   7.0 13th 0
Mango Farm 33.2 -0.2 37.5 25th 11.5 -4.4 7.0 13th 0 2.1 lowest 0%
McCluer Island 27.2 -0.6 29.9 23rd 22.5 -0.7 20.5 14th 0 0.4 lowest 0%
Middle Point 34.5 +0.6 38.1 26th 12.3 -2.8 5.0 13th 0 0.8 lowest 0%
Noonamah 34.4   38.0 26th 13.5   8.6 13th 0.6
Oenpelli 33.7 0.0 36.1 24th 15.6 -2.9 12.5 13th 0 1.0 lowest 0%
Pirlangimpi 32.8 +0.8 35.6 28th 18.0 -1.1 14.1 14th 0 6.6 lowest 0%
Port Keats Aero 31.6 -0.3 34.1 26th 14.7 -2.8 11.0 14th 0.6 0.3 high 200%
Tindal RAAF 32.5 +0.4 36.6 26th 11.5 -3.9 4.7 12th 0 1.3 lowest 0%
Arnhem (district 14BC)
Cape Wessel 29.4   30.9 25th 22.7   21.1 12th 0 7.8 lowest 0%
Gove Airport 28.6 0.0 30.9 22nd 17.6 -1.6 13.7 17th 2.2 5.5 average 40%
Groote Eylandt Airport 29.6 -0.5 33.1 26th 13.9 -1.3 8.4 13th 0.8 1.0 high 80%
Maningrida Aero 31.3   35.1 27th 16.1   12.2 12th 0
Milingimbi 30.7   33.7 27th 17.7   12.4 13th 0 3.5 lowest 0%
Ngayawili 30.4 0.0 33.3 28th 18.7 -0.6 15.8 12th 1.0 1.2 high 83%
North East Island 26.5   28.8 25th 20.8   18.6 16th 5.0 1.4 high 357%
Warruwi 29.5 +0.3 32.8 31st 20.6 -1.1 16.9 13th 0 0.5 lowest 0%
Roper-Mcarthur (district 14DE)
Bulman 32.4   36.0 24th 10.9   6.0 12th 0 0.9 lowest 0%
Centre Island 27.6 -0.2 30.9 29th 18.1 -1.4 15.2 3rd 1.6 1.6 average 100%
Daly Waters 32.5 +1.5 36.8 26th 8.6 -4.4 3.3 13th 0 0.4 lowest 0%
McArthur River Mine 32.7 +0.8 37.0 25th 10.6 -2.8 4.4 13th 0 0.4 lowest 0%
Ngukurr 31.7   35.1 23rd 12.6   6.8 12th 0
Wollogorang 31.5 +0.4 34.8 24th 9.6 -2.6 3.3 13th 0 0.6 lowest 0%
Victoria (district 14F)
Lajamanu 30.5 +0.9 36.1 30th 8.5 -2.6 2.5 14th 0 0.8 lowest 0%
Timber Creek 33.2 +0.3 37.7 26th 12.5 -3.5 8.3 21st 0 0.6 lowest 0%
Victoria River Downs 32.5 +0.6 37.5 26th 9.4 -3.9 3.2 1st 0 1.0 lowest 0%
Barkly (district 15A)
Brunette Downs 29.8 +0.2 35.7 23rd 10.2 -2.3 4.8 14th 0 1.4 lowest 0%
Elliott 30.9 -0.4 35.4 30th 10.0 -3.3 5.0 3rd 0 1.1 lowest 0%
Tennant Creek Airport 27.9 +0.4 33.8 22nd 13.2 -1.2 8.6 2nd 0 1.6 lowest 0%
Alice Springs (district 15B)
Alice Springs Airport 24.9 +2.2 33.0 22nd 4.3 -1.8 -3.6 1st 0 9.2 lowest 0%
Arltunga 23.7 +0.9 31.5 29th 3.5 -1.7 -4.7 2nd 0 6.8 lowest 0%
Curtin Springs 25.0 +2.0 32.5 28th 5.0 -0.7 -1.9 2nd 0 8.3 lowest 0%
Jervois 25.5 +0.5 34.5 29th 6.0 -1.1 -1.5 2nd 0 7.6 lowest 0%
Kulgera 23.3 +1.3 31.8 28th 6.0 -0.7 -2.7 12th 0 8.9 lowest 0%
Papunya     32.0 29th 7.0   0.9 2nd 0 6.1 lowest 0%
Rabbit Flat 30.0 +0.7 36.0 30th 6.6 -1.9 -0.7 1st 0 1.5 lowest 0%
Territory Grape Farm 26.2 +1.0 33.2 29th 5.1 -2.0 -1.2 1st 0 5.0 lowest 0%
Walungurru 28.3   34.3 29th 11.3   3.9 2nd 0 5.9 lowest 0%
Yulara Aero 25.1 +1.6 33.0 28th 4.7 -1.3 -2.0 1st 0 4.8 lowest 0%

Notes

A Monthly Climate Summary is prepared to list the main features of the weather in Northern Territory 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 1 pm on Thursday 30 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 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

Media
(03) 9669 4057
Enquiries