Monday, 3 October 2011 - Seasonal Climate Summary for Northern Territory - Product code IDCKGC12R0

Northern Territory in Dry Season 2011: Cool and Dry

  • Darwin Airport
    • Coolest dry season nights on record
    • 94 nights below 20 °C
  • 3rd driest May-Sept in Alice Springs District
  • Record cool temperatures and across the Territory
  • Bushfires burn across the Territory

Extremes Records Summaries Important notes the top

Darwin Airport sets 2 minimum temperature records

This dry season has been extraordinarily cool with a mean dry season minimum temperature at Darwin Airport of 19.2 °C. The previous record for coolest dry season was 19.4 °C set in 2006. The long-term average dry season minimum temperature at Darwin Airport (period of 1 May to 30 September) is 21.0 °C. The coolest night was on June 14th when the mercury fell to 12.7 °C. This was the coolest night since 27 June 2008. (The record coolest dry season night still stands at 10.4 °C set on 29 July 1942.)

Darwin Airport recorded 94 nights below 20 °C. In an average dry season the overnight temperature will drop below 20 °C about 50 times. The previous highest number nights below 20 °C was 92 nights set in 1976. Last year's dry season only saw 24 nights below 20 °C.

Arltunga breaks 113 year old record in May

On the 28 May the minimum temperature at Arltunga dropped to −3.8 °C breaking the long-held Northern Territory record for the coldest May minimum temperature of −3.0 °C set at Alice Springs Post Office on 27 May 1898. This new record was then broken again on the 31 May when the minimum temperature at Arltunga dropped to −4.2 °C. While not an all-time record, Arltunga felt the coldest temperature this dry season with -6.1 °C on 25 July 2011. The record lowest dry season temperature still stands at -7.5 °C set at Alice Springs Airport on 17 July 1976.

Bushfires

The Northern Territory has had several dry months following a record-setting wet season. The lush biota has now become ample fuel for bushfires in the NT. In addition to a high fuel load, dry and gusty southeast winds raised the fire danger index (FDI) across the Territory. The FDI reached "catastrophic" levels 9 times in the NT this dry season. Significant fires were reported in every month of the dry season but August and September were especially bad in the Top End and throughout the red centre. A total of 22 fire ban days were issued by fire authorities during August and September for various Fire Protection Zones across the Territory. Several thousands of square kilometers have burned across the Territory but especially around the Alice Springs area. Local media at Alice Springs reported that an area greater than Tasmania has been burned by bushfires durring September.

Rainfall: Dry in the Alice

The Alice Springs District usually gets between 55 mm and 70 mm in the May through September period from frontal passages along the southern border. This season, however, persistent high pressure over central Australia prevented most of the cold fronts from moving into the Territory. Several locations, including Alice Springs Airport, did not receive any rainfall in August or September. By the end of the dry season Alice Springs Airport had recorded only 17.6 mm. This is only 27% of their average and marks the third driest May through September period on record.

The wettest overall was Yulara with 91.4 mm, followed by Curtin Springs with 71.8 mm, and then Walungurru with 61.8 mm. The wettest single day was at Tobermorey with 29.0 mm on 15 Jul, followed by Yulara with 26.8 mm on 8 Jun, and then Walungurru with 26.4 mm on 9 Jun.

Temperatures: Record cool dry season

The dry season 2011 came after one of the wettest wet seasons on record. As the monsoon retreated and the winds shifted to a south-southeasterly direction cool, dry air moved across the wet terrain and brought below average temperatures to the Top End. May and June saw record low minimum temperatures at Darwin Airport, Tennant Creek Airport, Alyangula Victoria River Downs, and Katherine Aviation Museum. Twelve locations around the Territory saw record low mean monthly temperatures in May when both the maximum and minimum temperatures were below average for most of the NT.

By July temperatures were returning to normal. Darwin Airport recorded above average monthly maximum temperatures for the first time since October 2010. Only one new temperature record was set in July, that was at McCluer Island when they reached 30.2 °C on the 31 July. It exceeded the previous record highest July temperature of 29.9 set on the 28th 2009.

The warmest on average was Jabiru Airport with 26.2 °C, followed by Warruwi with 25.5 °C, and then Pirlangimpi with 25.3 °C. The coolest on average was Arltunga with 12.9 °C, followed by Alice Springs Airport with 14.0 °C, and then Yulara with 14.6 °C.

Maximum temperature

The hottest days were at Bradshaw with 39.7 °C on 30 Sep and then 39.2 °C on 27 Sep. This was followed by Jabiru Airport with 39.1 °C on 22 Sep, and then Timber Creek with 39.0 °C on 19 Sep, and again on the 26 Sep. The warmest days on average were at Noonamah with 33.2 °C, followed by Jabiru Airport with 33.0 °C, and then Middle Point with 32.7 °C.

The coolest days on average were at Arltunga with 22.2 °C, followed by Kulgera with 22.4 °C, and then Alice Springs Airport and Yulara with 22.9 °C.

The coldest day was at Kulgera with 10.2 °C on 13 Jul, followed by Alice Springs Airport with 10.5 °C on 14 Jul, and then Arltunga with 10.8 °C on 9 Jun. Curtin Springs also recorded 10.8 °C on 13 Jul.

Alyangula Police had their lowest May to September mean daily maximum temperature on record with an average maximum temperature of 28.5 °C, this breaks the record of 28.6 °C set in 2006.

Minimum temperature

Several sites across the Territory saw record cool nights this dry season. The stations with more than 20 years of record are included in the records table below. Other stations, with shorter records include Lajamanu where the average minimum temperature for the May through September period was 9.4 °C which is 2.6 below the average and 0.6 °C below the record set in 2006. Groote Eylandt Airport also set a new minimum temperature record with a seasonal average minimum temperature of 15.2 °C--this is 1.3 °C below average for them and 0.4 below the record set in 2006. Point Fawcett, Delamere Weapons Range and Borroloola also set new records. Among the sites that had their lowest May to September mean daily minimum temperature on record and with greater than 20 years of record were Darwin Airport and Katherine Aviation Museum.

The coldest nights in the NT for the May to September period were at Arltunga with -6.1 °C on 25 Jul, -6.0 °C on 24 Jul, and then -5.0 °C on 1 Jun.

The coolest nights on average were at Arltunga with 3.6 °C, followed by Alice Springs Airport with 5.1 °C, and then Territory Grape Farm with 5.8 °C.

The warmest nights on average were at North East Island with 22.5 °C, followed by Warruwi with 21.6 °C, and then Gove Airport and Ngayawili with 19.5 °C.

The warmest night was at McCluer Island with 27.3 °C on 8 May.

Wind

The strongest wind gust was at Yulara with 78 km/h on 27 Sep, followed by Walungurru with 69 km/h on 8 Sep, and then Jervois with 65 km/h on 28 Sep.

Further information

NT Climate Services Centre
Bureau of Meteorology
Phone (08) 8920 3813
Email climate.nt@bom.gov.au
Extremes in May to September 2011
Hottest day 39.7 °C at Bradshaw on 30 Sep
Warmest days on average 33.2 °C at Noonamah
Coolest days on average 22.2 °C at Arltunga
Coldest day 10.2 °C at Kulgera on 13 Jul
Coldest night -6.1 °C at Arltunga on 25 Jul
Coolest nights on average 3.6 °C at Arltunga
Warmest nights on average 22.5 °C at North East Island
Warmest night 27.3 °C at McCluer Island on 8 May
Warmest on average overall 26.2 °C at Jabiru Airport
Coolest on average overall 12.9 °C at Arltunga
Wettest overall 91.4 mm at Yulara
Wettest day 29.0 mm at Tobermorey on 15 Jul
Highest wind gust 78 km/h at Yulara on 27 Sep

Extremes Records Summaries Important notes the top


Record lowest May to September mean daily maximum temperature
Mean daily maximum
temperature
for May to September 2011 (°C) 		Previous coolest
for May to September		 Years of
record		 Average for
May to September
Alyangula Police 28.5 28.6 in 2006 27 29.5


Record lowest May to September mean daily minimum temperature
Mean daily minimum
temperature
for May to September 2011 (°C) 		Previous coolest
for May to September		 Years of
record		 Average for
May to September
Darwin Airport 19.2 19.4 in 2006 68 21.0
Larrimah 11.6 12.0 in 1976 44 14.9
Daly Waters 10.3 11.8 in 2006 40 14.3
Timber Creek 14.7 14.9 in 2006 29 17.0
Katherine Aviation Museum 13.5 13.6 in 2006 24 15.6


Extremes Records Summaries Important notes the top

Summary statistics for May to September 2011
Maximum temperatures
(°C)		 Minimum temperatures
(°C)		 Rainfall
(millimetres)
Mean Diff
from
average		 Highest Mean Diff
from
average		 Lowest Total Average
for
May
to September		 Rank Fraction
average
Darwin-Daly (district 14GA)
Batchelor 32.0 -1.1 37.4 26 Sep 16.6 -1.2 8.0 16 Jun 0 25.0 v low 0%
Bradshaw 32.2   39.2 27 Sep 15.7   6.7 13 Jun 1.0
Darwin Airport 31.1 -0.3 34.9 27 Sep 19.2 -1.8 12.7 14 Jun 3.8 44.3 low 9%
Delamere Weapons Range 30.1 -1.4 37.4 19 Sep 14.8 -2.0 6.6 18 Jun 0 10.4 v low 0%
Douglas River 32.1 -1.1 38.7 27 Sep 14.0 -1.0 4.1 16 Jun 0 19.7 lowest 0%
Jabiru Airport 33.0 -0.4 39.1 22 Sep 19.4 -0.6 10.7 14 Jun 4.0 22.8 average 18%
Katherine Aviation Museum 30.7 -1.5 37.4 27 Sep 13.4 -2.2 5.5 16 Jun 0 12.1 lowest 0%
Mango Farm 31.9 -1.2 38.2 27 Sep 15.3 -1.6 5.1 14 Jun 20.8 21.0 high 99%
Middle Point 32.7   37.9 25 Sep 14.8   6.3 17 Jun 0
Noonamah 33.2   38.2 5 Sep 15.6   8.4 20 Jun 0
Pirlangimpi 31.7 -0.2 35.5 5 Sep 18.8 -0.9 11.1 14 Jun 20.8 65.9 low 32%
Point Fawcett 30.0 -0.6 32.8 30 Aug 16.8 -3.1 8.2 15 Jun 5.4 44.3 average 12%
Port Keats 31.5   36.3 30 Aug 17.0   8.6 14 Jun 0.6
Tindal RAAF 31.0 -0.9 37.7 23 Sep 14.0 -2.1 6.0 15 Jun 0 13.8 lowest 0%
Arnhem (district 14BC)
Alyangula Police 28.5 -1.0 32.8 27 Sep 17.9 -1.3 11.5 13 Jun 41.6 51.8 average 80%
Gove Airport 29.0 +0.1 33.3 21 Sep 19.5 -1.1 13.1 11 Aug 26.6 152.7 v low 17%
Groote Eylandt Airport 29.6 -0.7 36.1 27 Sep 15.2 -1.3 7.1 14 Jun 5.8 32.2 low 18%
Maningrida 31.1   35.4 30 Aug 18.3   8.8 15 Jun 0.2
Milingimbi 30.9   34.6 31 Aug 19.2   11.0 15 Jun 4.8
Ngayawili 30.1 -0.3 33.8 29 Aug 19.5 -0.7 10.5 15 Jun 2.2 51.8 low 4%
North East Island 27.3   31.4 1 May 22.5   19.7 13 Jun 24.6 37.4 average 66%
Warruwi 29.3 -0.4 33.6 19 Sep 21.6 -0.9 15.5 15 Jun
Roper-Mcarthur (district 14DE)
Borroloola 30.5 -1.4 36.5 22 Sep 12.0 -2.4 4.6 13 Jun 2.0 7.7 average 26%
Bulman 31.4   38.2 27 Sep 14.3   5.5 15 Jun 6.4
Centre Island 27.2 -0.9 32.8 29 Sep 19.2 -1.2 13.2 11 Jun 4.6 22.4 low 21%
Daly Waters 30.1 -0.7 37.8 26 Sep 10.3 -4.0 2.0 14 Jun 0 14.6 lowest 0%
Larrimah 30.3 -1.2 36.7 27 Sep 11.6 -3.3 3.4 13 Jun 0 18.9 lowest 0%
McArthur River Mine 31.2 -0.6 38.0 24 Sep 12.8 -1.6 4.8 19 Jun 0.4 17.4 low 2%
Ngukurr 30.4 -1.3 37.9 26 Sep     9.5 15 Jun 0.7 17.1 average 4%
Wollogorang 30.2 -0.8 37.7 22 Sep 11.3 -2.2 4.1 18 Jun 0.7 11.5 average 6%
Victoria (district 14F)
Lajamanu 28.6 -0.8 38.6 27 Sep 9.4 -2.6 1.7 14 Jun 4.0 19.7 average 20%
Timber Creek 31.8 -0.8 39.0 26 Sep 14.7 -2.3 6.0 19 Jun 0 17.9 lowest 0%
Victoria River Downs 30.9 -0.6 38.7 19 Sep 11.2 -2.9 3.9 15 Jun 0 16.6 lowest 0%
Wave Hill 29.3 -1.5 37.8 27 Sep 11.1 -2.4 2.8 2 Jun 1.0 27.3 low 4%
Barkly (district 15A)
Tennant Creek Airport 26.1 -1.1 36.5 28 Sep 13.1 -1.8 5.7 11 Jun 10.4 27.3 average 38%
Alice Springs (district 15B)
Alice Springs Airport 22.9 +0.4 35.8 27 Sep 5.1 -1.7 -3.4 15 Jun 17.6 64.8 low 27%
Arltunga 22.2   35.4 28 Sep 3.6   -6.1 25 Jul 20.4 55.8 low 37%
Curtin Springs 23.4 +0.4 37.0 26 Sep     -1.0 24 Jul 71.8 61.2 average 117%
Jervois 24.0 -0.9 36.6 28 Sep 6.8 -1.2 -0.3 1 Jun 15.0 56.1 low 27%
Kulgera 22.4 +0.5 36.4 27 Sep 6.7 -0.8 -2.1 30 May 54.4 63.6 average 86%
Papunya 24.7   36.5 27 Sep 8.5   0.7 19 Jun 11.2 59.5 low 19%
Rabbit Flat 27.7 -1.3 38.8 27 Sep 7.9 -1.9 0.7 16 Jun 11.0 27.1 average 41%
Territory Grape Farm 25.0 -0.4 37.3 28 Sep 5.8 -2.3 -2.1 1 Jun 17.0 52.6 low 32%
Walungurru 26.0   38.0 26 Sep 12.4   4.7 13 Jun 61.8
Yulara 22.9 -0.7 35.7 26 Sep 6.3 -1.0 -0.7 16 Jun 91.4 57.9 high 158%

Extremes Records Summaries Important notes the top

Notes

This statement was prepared before all data for the period were available. This may affect some of the statistics presented.

A Seasonal 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 Friday 30 September 2011. 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 the years 1800 to 2009. They are not shown for sites with less than 10 years of record in that time, 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

NT Climate Services Centre
Bureau of Meteorology
Phone (08) 8920 3813
Email climate.nt@bom.gov.au