Northern Territory in September 2020: record heat and average rainfall

September was notable for the very warm days and nights observed across all of the Northern Territory. Territory-wide, the mean night-time temperature was the highest on record, while the mean daytime temperature was the second-highest ever recorded for September. Rainfall across the NT was very near to the long-term average for the month.

Days and nights more than 3 °C above average

Above average rain across much of the northern NT

  • For the first September since 2016, NT rainfall was above average in 2020; Territory-wide, rainfall was 16% above the long-term average.
  • Above average rainfall was mostly confined to the northern two-thirds of the Territory, with only small rainfall totals observed across most of the south.
  • Parts of the northwestern Top End had totals in excess of 50 mm during the month, with many locations recording rainfall totals in the highest 10% of all historical observations.
  • Many sites in the northern NT had either their highest September daily rainfall on record, their highest total September rainfall on record or their highest total September rainfall for at least 20 years.
  • For the year to date, Territory-wide rainfall was 11% below the long-term average.

Darwin Airport

  • Total rainfall for Darwin Airport was 86.8 mm, which is 526% of the long-term average of 16.5 mm.
  • The mean daily maximum temperature for Darwin Airport was 33.9 °C, which is 1.3 °C above the long-term average of 32.6 °C
  • The warmest day was 37.0 °C on the 8th, and the coolest day was on the 20th when the temperature reached 31.9 °C.
  • The mean daily minimum temperature for Darwin Airport was 23.7 °C, which is 0.7 °C above the long-term average of 23.0 °C
  • The coldest morning was 21.1 °C on the 13th, and the warmest morning was on the 24th when the minimum temperature was 25.5 °C.
  • Darwin Airport did not have any minimum temperatures below 20 °C in September; in an average year, there are between 1 and 2 nights this cool.

Alice Springs Airport

  • Total rainfall for Alice Springs Airport was 0.2 mm, which is 2% of the long-term average of 8.6 mm.
  • The mean daily maximum temperature for Alice Springs Airport was 31.7 °C, which is 4.3 °C above the long-term average of 27.4 °C. The warmest day was 35.9 °C on the 20th, and the coolest day was on the 26th when the temperature reached 26.4 °C.
  • The mean daily minimum temperature for Alice Springs Airport was 13.8 °C, which is 3.5 °C below the long-term average of 10.3 °C. The coldest morning was 6.7 °C on the 1st, and the warmest morning was on the 17th, when the minimum temperature was 24.3 °C.

Further information

Media
(03) 9669 4057

Extremes in September 2020
Hottest day 40.8 °C at Victoria River Downs on the 20th
Warmest days on average 38.4 °C at Bradshaw - Angallari Valley (Defence)
38.4 °C at Bradshaw - Koolendong Valley (Defence)
Coolest days on average 29.0 °C at McCluer Island
Coldest day 25.0 °C at Arltunga on the 26th
Coldest night 5.0 °C at Arltunga on the 2nd
Coolest nights on average 13.2 °C at Arltunga
Warmest nights on average 25.7 °C at McCluer Island
Warmest night 28.4 °C at Wave Hill on the 21st
Warmest on average overall 31.4 °C at Bradshaw
Coolest on average overall 21.8 °C at Arltunga
Wettest overall 118.2 mm at Charles Darwin University
Wettest day 77.6 mm at Dum In Mirrie Airstrip on the 25th
Strongest wind gust 83 km/h at Walungurru Airport on the 17th

Maps
ObservedAnomalyDecile 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

Click on a map to show it full size in a pop-up window


Record highest September daily rainfall
New record
(mm)
Old
record
Years of
record
Darwin River Dam 58.0 on the 26th 45.4 on the 29th in 1981 50
Timber Creek 31.0 on the 23rd 29.4 on the 28th in 1981 40
Keep River Rangers 18.0 on the 25th 12.0 on the 30th in 1988 36
Mount Sanford 29.0 on the 27th 23.0 on the 19th in 2016 32
Dum In Mirrie Airstrip 77.6 on the 25th 40.0 on the 16th in 2002 23
Killarney 12.5 on the 22nd 9.3 on the 24th in 1998 22



Record highest September total rainfall
New record
(mm)
Old
record
Years of
record
Average for
September
Timber Creek 34.7 32.4 in 1981 40 6.0
Keep River Rangers 25.0 13.8 in 1988 36 2.4
Mount Sanford 41.0 32.1 in 2016 32 4.2
Karama 69.0 59.0 in 2009 31 11.5
Darwin Hospital 97.6 78.2 in 2015 25 16.8
Dum In Mirrie Airstrip 108.4 65.0 in 2010 23 17.1
Killarney 22.5 9.3 in 1998 22 2.3
Port Keats Airport 49.4 43.6 in 2018 22 6.9
Bradshaw 12.0 11.0 in 2001 21 2.3
Middle Point 48.6 42.0 in 2002 20 16.9

Highest September total rainfall for at least 20 years
Observed
(mm)
Most recent
higher
Average for
September
Darwin Airport 86.8 129.8 in 1981 16.5
Darwin River Dam 76.6 107.2 in 1981 16.7
Tipperary 39.0 44.5 in 1943* 6.3
Brunette Downs 18.6 19.4 in 1992 5.8
Nightcliff Pool 75.7 84.2 in 1981* 18.7

* note: there are gaps in the historical record at this site, so it is possible a higher value has gone unreported




Record highest September temperature
New record
(°C)
Old
record
Years of
record
Average for
September
Victoria River Downs 40.8 on the 20th 40.7 on the 28th in 2016 55 35.7
Point Fawcett 36.0 on the 8th 35.5 on the 16th in 2017 23 32.2
Dum In Mirrie Airstrip 37.5 on the 8th 37.0 on the 26th in 2001 21 31.8



Record highest September mean daily maximum temperature
New record
(°C)
Old
record
Years of
record
Average for
September
Jabiru Airport 37.6 37.4 in 2017 42 36.3
McArthur River Mine Airport 37.1 37.0 in 2017 41 35.4
Tindal RAAF 37.5 37.3 in 2012 32 35.9
Delamere Weapons Range 36.8 36.7 in 2009 23 35.7
Point Fawcett 33.6 = 33.6 in 2017 22 32.2
Groote Eylandt Airport 33.3 = 33.3 in 2009 21 32.5
Dum In Mirrie Airstrip 33.6 33.0 in 2017 20 31.8



Record highest September daily minimum temperature
New record
(°C)
Old
record
Years of
record
Average for
September
Brunette Downs 25.9 on the 20th 25.8 on the 28th in 1997 53 16.7
Wave Hill 28.4 on the 21st = 28.4 on the 29th in 1992 47 17.9
Elliott 27.4 on the 21st 27.3 on the 20th in 1986 39 17.4
Delamere Weapons Range 27.3 on the 20th 27.1 on the 22nd in 2013 24 20.6
Rabbit Flat 25.9 on the 29th 25.3 on the 28th in 2005 24 14.1
Middle Point 25.5 on the 21st 25.1 on the 18th in 2016 20 18.9



Highest September mean daily minimum temperature for at least 20 years
Observed
(°C)
Most recent
higher
Average for
September
Tennant Creek Airport 21.2 21.4 in 1997 18.4
Yulara Airport 13.3 =13.3 in 1998 10.7



Record highest September mean temperature
New record
(°C)
Old
record
Years of
record
Average for
September
Yulara Airport 22.7 22.5 in 2013 32 19.7
Bradshaw 31.4 = 31.4 in 2010 21 29.7

Highest September mean temperature for at least 20 years
Observed
(°C)
Most recent
higher
Average for
September
Wave Hill 29.3 29.8 in 1992 26.5
Elliott 28.6 28.8 in 1997* 26.4

* note: there are gaps in the historical record at this site, so it is possible a higher value has gone unreported




Summary statistics for September 2020
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
September
2020
Diff
from
average
Highest for
September
2020
Mean for
September
2020
Diff
from
average
Lowest for
September
2020
Total for
September
2020
Average
for
September
Rank of
September
2020
Fraction of
September
average
Darwin-Daly (district 14GA)
Batchelor Airport 36.7 +0.7 38.3 6th 21.6 +1.1 18.0 7th 6.0 7.7 average 78%
Central Arnhem Plateau 34.9 +1.1 37.4 21st 20.9 +1.9 16.4 12th 4.8 5.0 high 96%
Channel Point 31.7 +0.6 35.5 7th     20.0 7th 45.3 11.3 v high 401%
Charles Point 30.8   35.1 8th 24.3   22.0 13th 48.8
Croker Island Airport 32.6   34.0 26th 24.3   22.8 5th 0
Darwin Airport 33.9 +1.3 37.0 8th 23.7 +0.7 21.1 13th 86.8 16.5 v high 526%
Delamere Weapons Range 36.8 +1.1 38.9 22nd 22.7 +2.1 18.4 12th 1.2 3.4 average 35%
Douglas River Research Farm 38.1 +1.3 39.9 28th 21.1 +2.6 16.7 8th 15.6 5.3 v high 294%
Dum In Mirrie Airstrip 33.6 +1.8 37.5 8th 23.0 +0.1 20.4 13th 108.4 17.1 highest 634%
Jabiru Airport 37.6 +1.3 39.4 22nd 23.0 +1.4 20.1 13th 10.4 11.7 high 89%
Kangaroo Flats (Defence) 37.3   39.0 6th 23.1   19.8 13th 17.0
McCluer Island 29.0 -0.1 31.0 25th 25.7 +1.0 24.7 5th 0 1.3 lowest 0%
Middle Point 36.9 +0.4 38.5 6th 20.8 +1.9 15.9 13th 48.6 16.9 highest 288%
Mount Bundey North (Defence) 37.3   38.7 5th 23.5   21.5 6th 40.6
Mount Bundey South (Defence) 37.4   39.4 22nd 22.8   19.5 7th 34.8
Murganella Airstrip 33.2   36.5 25th 21.6   18.3 7th 7.4
Noonamah Airstrip 36.4   38.4 5th 23.1   18.9 13th 59.0
Oenpelli Airport 37.6   39.2 27th 21.4   15.4 7th 0.4
Pirlangimpi Airport 34.2 +0.8 36.2 23rd 22.6 +1.3 19.5 13th 35.2 27.2 high 129%
Point Fawcett 33.6 +1.4 36.0 8th 21.6 +0.6 17.0 13th 8.4 8.8 high 95%
Point Stuart 34.2   36.2 9th 22.3   19.3 7th 38.0 11.1 v high 342%
Port Keats Airport 33.7 +0.1 35.7 7th 22.8 +2.0 19.8 8th 49.4 6.9 highest 716%
Tindal RAAF 37.5 +1.6 39.3 29th 21.4 +1.6 15.7 12th 5.6 8.3 high 67%
Arnhem (district 14BC)
Cape Wessel 31.9   33.4 24th 24.7   23.2 3rd 5.2 6.3 high 83%
Gove Airport 31.2 +0.8 32.9 25th 21.6 +1.9 18.1 12th 7.8 6.5 high 120%
Groote Eylandt Airport 33.3 +0.8 36.0 28th 18.6 +0.8 14.8 12th 0 7.2 lowest 0%
Maningrida Airport 32.9 +0.6 34.6 25th 21.4 +1.1 18.3 5th 0 6.2 v low 0%
Milingimbi Airport 32.8 +0.9 33.9 26th 22.6 +1.3 19.6 10th 0 3.7 v low 0%
Warruwi Airport 31.4 +0.5 35.0 25th 24.9 +1.3 23.2 5th 1.8 1.4 high 129%
Roper-Mcarthur (district 14DE)
Borroloola Airport 36.0 +0.9 38.7 27th 18.9 +1.4 16.0 11th 7.2 3.4 high 212%
Bulman 37.1 +0.8 39.3 22nd 20.4 +2.5 16.2 12th 0 14.9 v low 0%
Centre Island 31.7 +1.1 34.1 23rd 23.6 +1.4 21.3 2nd 0.4 1.8 average 22%
Daly Waters Airstrip 36.9 +2.0 38.9 21st 18.7 +2.0 14.2 12th 2.6 1.9 high 137%
McArthur River Mine Airport 37.1 +1.7 39.8 27th 19.3 +2.0 15.9 5th 0 4.7 lowest 0%
Ngukurr Airport 36.8   40.1 21st 20.8   17.4 12th 0
Victoria (district 14F)
Bradshaw 38.3 +0.8 40.4 20th 24.5 +2.6 21.5 9th 12.0 2.3 highest 522%
Bradshaw - Angallari Valley (Defence) 38.4   40.6 28th 24.0   21.2 12th 5.0
Bradshaw - Koolendong Valley (Defence) 38.4   40.5 28th 20.6   14.2 10th 18.0
Lajamanu Airport 36.9 +2.2 39.3 21st 19.7 +3.1 15.9 9th 17.0 4.6 v high 370%
Victoria River Downs 37.7 +2.0 40.8 20th 21.2 +3.1 16.9 8th 20.6 4.4 v high 468%
Wave Hill 37.3 +2.1 40.2 21st 21.4 +3.5 16.4 10th 3.8 12.4 average 31%
Barkly (district 15A)
Elliott 36.5 +1.2 39.7 21st 20.6 +3.2 15.7 2nd 8.4 5.5 high 153%
Tennant Creek Airport 34.7 +3.0 38.2 21st 21.2 +2.8 18.3 2nd 9.6 7.4 high 130%
Alice Springs (district 15B)
Alice Springs Airport 31.7 +4.3 35.9 20th 13.8 +3.5 6.7 1st 0.2 8.6 low 2%
Arltunga 30.5 +2.9 35.3 20th 13.2 +3.2 5.0 2nd 1.4 7.5 average 19%
Curtin Springs 31.8 +3.9 37.6 7th 13.4 +3.4 6.2 22nd 5.0 9.8 average 51%
Jervois 33.0 +3.3 38.5 20th 14.4 +3.1 8.3 7th 0 10.3 lowest 0%
Rabbit Flat 36.5 +2.1 40.1 30th 16.0 +1.9 8.8 1st 3.6 5.1 high 71%
Territory Grape Farm 33.1 +2.8 36.8 20th 14.6 +2.8 8.3 2nd 0 9.8 lowest 0%
Walungurru Airport 34.1 +2.3 37.7 8th 19.3 +2.6 9.8 19th 3.4 7.1 average 48%
Yulara Airport 32.0 +3.2 36.8 8th 13.3 +2.6 6.9 22nd 1.6 8.3 average 19%

Notes

The Monthly climate summary, generally published on the first working day of each month, lists 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. More extensive discussion of significant weather events, along with later information and data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review.

This statement has been prepared based on information available at 11 am on Thursday 1 October 2020. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

In some situations, some or all of the rainfall is in the form of hail or snow. In these cases the totals given are for the water equivalent: the depth of liquid water that results from melting any frozen precipitation. There can be significant 'undercatch' of snow in strong winds, meaning the true precipitation can be higher than that reported.

Averages for individual sites 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.

Where temperature area averages are mentioned, they are derived from the ACORN-SAT dataset.

Further information

Media
(03) 9669 4057

Climate