Northern Territory in October to April 2020-21: highest rainfall since 2016-17

Most parts of the Northern Territory recorded above average rainfall during the wet-season months of October to April. Temperatures were generally warmer than average in the north and near or below average in the southern Territory, with cool days observed in the south-west. For the first wet season since 2015–16, no tropical cyclones passed over Northern Territory waters.

Rainfall generally above average

  • Apart from areas across the central Territory and eastern border region, rainfall totals during the wet season were generally above average; Territory-wide, rainfall was 21% above the long-term average, and the highest since the wet season of 2016-17.
  • Four of the 7 months of the wet season saw above average rainfall across the Territory, starting with an unusually wet October as La Niña became established in the Pacific Ocean.
  • December saw an early monsoon onset at Darwin on the 19th, and the associated rain saw the Territory have its fifth-wettest December on record.
  • A relatively dry start to January 2021 was followed by a monsoon burst late in the month, although rainfall was 20% below average overall for the month.
  • Monsoonal conditions continued into early February, leading to above average rainfall.
  • While rainfall in the northern half of the Territory was below average during March, tropical low activity affected southern and western areas, leading to slightly above average rainfall for the month.
  • The final month of the wet season saw mostly dry conditions during April, with no monsoonal activity affecting the Territory.
  • Two sites had their highest total October to April rainfall on record; several other sites had their highest October to April daily rainfall on record.

Warm days and nights in the north

  • Overall, both daytime and night-time temperatures across the Territory were marginally above the long-term average; the mean maximum temperature was 0.34 °C above average while the mean minimum temperature was 0.78 °C above average.
  • Daytime temperatures were somewhat above average across the Top End and over the eastern half, south of the Top End; elsewhere it was close to average, although parts of the south-west had cooler than average days.
  • Much of the northern and eastern Territory had above average night-time temperatures, with the south-west region seeing close to average night-time temperatures.
  • Several sites in the south-western Territory had their coldest October to April day on record, associated with widespread rainfall in early October.
  • Temperatures for the individual months of the wet season were generally close to average, apart from November and December.
  • The influence of La Niña was weaker during November 2020, contributing to the warmest November on record for the Territory for maximum, minimum and mean temperature.
  • December was much cooler than average, related to the widespread rainfall, with the mean maximum temperature 1.70 °C below average, the lowest for December since 2000.
  • Some sites had their lowest October to April temperature on record.

Darwin Airport

  • Total rainfall for Darwin Airport was 1857.8 mm, which is 111% of the long-term average of 1676.4 mm.
  • Darwin's wet-season rainfall total was the highest since 2017–18 when 2038.6 mm was recorded.
  • The highest daily rainfall total was 119.4 mm on 8 October; this was the first time a daily rainfall total above 100 mm was observed at Darwin Airport since 30 January 2018, when 155.2 mm was recorded.
  • The mean daily maximum temperature for Darwin Airport was 32.8 °C, which is 0.3 °C above the long-term average of 32.5 °C.
  • The warmest day was 37.0 °C on 20 November, and the coolest day was on 28 January when the temperature reached 27.1 °C.
  • The mean daily minimum temperature for Darwin Airport was 25.1 °C, which is 0.3 °C above the long-term average of 24.8 °C.
  • The coldest morning was 18.9 °C on 25 April, the earliest sub-20 °C April temperature since 2017, and the warmest morning was on 4 January when the minimum temperature was 29.3 °C.

Alice Springs Airport

  • Total rainfall for Alice Springs Airport was 275.6 mm, which is 127% of the long-term average of 217.6 mm.
  • Alice Spring's wet-season rainfall total was the highest since 2010–11 when 491.4 mm was recorded.
  • The highest daily rainfall total was 49.8 mm on 22 March.
  • The mean daily maximum temperature for Alice Springs Airport was 33.1 °C, which is 0.2 °C below the long-term average of 33.3 °C.
  • The warmest day was 43.7 °C on 28 November, and the coolest day was on the 5 October when the temperature reached 13.0 °C.
  • The mean daily minimum temperature for Alice Springs Airport was 18.2 °C, which is 0.3 °C above the long-term average of 17.9 °C.
  • The coldest morning was 3.9 °C on 19 April, and the warmest morning was on 11 November when the minimum temperature was 30.7 °C.

Further information

Media
(03) 9669 4057

Extremes in October to April 2020-21
Hottest day 46.0 °C at Jervois on 5 Dec 2020
Warmest days on average 37.0 °C at Elliott
Coolest days on average 31.1 °C at McCluer Island
Coldest day 12.5 °C at Arltunga on 5 Oct 2020
12.5 °C at Watarrka on 5 Oct 2020
12.5 °C at Watarrka on 6 Oct 2020
Coldest night 3.9 °C at Alice Springs Airport on 19 Apr 2021
Coolest nights on average 18.2 °C at Alice Springs Airport
Warmest nights on average 26.7 °C at McCluer Island
Warmest night 32.7 °C at Walungurru Airport on 29 Nov 2020
Warmest on average overall 30.9 °C at Bradshaw
30.9 °C at Bradshaw - Angallari Valley (Defence)
Coolest on average overall 25.7 °C at Alice Springs Airport
Wettest overall 2328.4 mm at Labelle Downs
Wettest day 327.4 mm at King Ash Bay on 19 Feb 2021
Strongest wind gust 115 km/h at Bradshaw on 11 Nov 2020

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 October to April daily rainfall
New record
(mm)
Old
record
Years of
record
Mount Denison 151.0 on 22 Dec 2020 135.0 on 16 Jan 1979 56
Daly Waters Airstrip 163.8 on 22 Feb 2021 156.8 on 30 Jan 2009 54
Humbert River 250.0 on 22 Feb 2021 148.1 on 12 Mar 1964 21



Record highest October to April total rainfall
New record
(mm)
Old
record
Years of
record
Average for
October to April
Territory Grape Farm 464.6 441.6 in 2009 29 243.9
Bullo River 1193.7 1110.4 in 2017 24 741.4



Record lowest October to April daily maximum temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Curtin Springs 13.0 on 5 Oct 2020 13.7 on 21 Apr 2000 57 34.4
Yulara Airport 12.6 on 6 Oct 2020 13.7 on 21 Apr 2000 35 34.9
Watarrka 12.5 on 5 Oct 2020 13.2 on 21 Apr 2000 30 35.2
Arltunga 12.5 on 5 Oct 2020 15.8 on 30 Apr 2014 21 33.2
Walungurru Airport 17.2 on 5 Oct 2020 19.0 on 13 Nov 2001 20 37.3



Record lowest October to April temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Channel Point 15.5 on 25 Apr 2021 16.5 on 30 Apr 2012 27 24.6
Dum In Mirrie Airstrip 16.3 on 25 Apr 2021 18.0 on 30 Apr 2012 23 25.5
Walungurru Airport 8.9 on 7 Oct 2020 10.3 on 3 Oct 2016 20 23.8



Summary statistics for October to April 2020-21
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
October
to April
2020-21
Diff
from
average
Highest for
October
to April
2020-21
Mean for
October
to April
2020-21
Diff
from
average
Lowest for
October
to April
2020-21
Total for
October
to April
2020-21
Average
for
October
to April
Rank of
October
to April
2020-21
Fraction of
October
to April
average
Darwin-Daly (district 14GA)
Batchelor Airport 34.0 -0.2 39.9 2 Nov 2020 23.5 0.0 13.2 25 Apr 2021 1127.0 1449.6 low 78%
Central Arnhem Plateau 33.0 -0.5 39.1 2 Nov 2020 22.9 0.0 15.3 25 Apr 2021 1366.0 1108.8 average 123%
Channel Point 32.2 0.0 35.0 4 Dec 2020 24.7 +0.1 15.5 25 Apr 2021 1921.6 1751.1 average 110%
Charles Point 31.9   35.5 10 Nov 2020 25.5   21.5 9 Mar 2021 1666.4
Croker Island Airport 32.3   37.3 2 Nov 2020 25.5   21.2 25 Apr 2021 1690.8
Darwin Airport 32.8 +0.3 37.0 17 Nov 2020 25.0 +0.2 18.9 25 Apr 2021 1857.8 1678.4 average 111%
Delamere Weapons Range 35.5 -0.1 42.1 3 Nov 2020 23.8 +0.1 14.1 14 Apr 2021 912.8 856.2 average 107%
Douglas River Research Farm 35.2 0.0 40.5 2 Oct 2020 23.4 +0.3 11.5 25 Apr 2021 1384.8 1268.7 average 109%
Dum In Mirrie Airstrip 32.7 +0.3 35.8 16 Nov 2020 25.1 -0.4 16.3 25 Apr 2021 1870.6 1717.6 average 109%
Jabiru Airport 35.4 +0.3 41.9 2 Nov 2020 24.9 +0.4 18.9 25 Apr 2021 1623.4 1496.1 average 109%
McCluer Island 31.1 -0.2 34.7 7 Nov 2020 26.7 +0.1 22.4 12 Apr 2021 1511.6 1101.2 v high 137%
Middle Point 34.3 -0.6 40.5 2 Nov 2020 23.7 +0.2 14.4 25 Apr 2021 1696.0 1335.1 high 127%
Mount Bundey North (Defence) 34.8   40.4 2 Nov 2020 24.3   19.3 25 Apr 2021 1655.8
Mount Bundey South (Defence) 35.2   40.5 2 Nov 2020 24.2   13.7 25 Apr 2021 1079.2
Murganella Airstrip 33.4   39.4 7 Nov 2020 23.8   14.9 25 Apr 2021 1513.4
Noonamah Airstrip 33.9   39.0 18 Nov 2020 24.3   14.8 25 Apr 2021 2145.6
Oenpelli Airport 35.0   41.7 2 Nov 2020 24.6   17.5 25 Apr 2021 1461.8
Pirlangimpi Airport 32.7 0.0 36.6 15 Nov 2020 24.2 +0.2 16.2 25 Apr 2021 1956.6 1929.6 average 101%
Point Fawcett 32.4 0.0 36.2 8 Nov 2020 24.7 -0.2 18.0 25 Apr 2021 1632.4 1479.6 average 110%
Point Stuart 33.1   38.8 7 Nov 2020 24.5   16.4 25 Apr 2021 1555.8 1345.8 average 116%
Port Keats Airport 33.4 -0.3 37.8 8 Nov 2020 24.5 0.0 17.0 25 Apr 2021 1574.8 1251.2 high 126%
Tindal RAAF 35.8 +0.4 42.4 2 Nov 2020 24.2 +0.5 13.9 25 Apr 2021 1294.8 1032.5 high 125%
Arnhem (district 14BC)
Cape Wessel 32.8   35.6 26 Nov 2020 25.6   22.0 8 Apr 2021 1647.6 1076.3 high 153%
Gove Airport 32.3 +0.3 37.2 30 Oct 2020 24.5 +0.7 19.4 30 Oct 2020 1387.4 1285.4 high 108%
Maningrida Airport 32.8 -0.1 37.9 15 Nov 2020 24.4 0.0 18.7 25 Apr 2021 1376.0 1198.8 high 115%
Milingimbi Airport 33.1 0.0 37.1 15 Nov 2020 24.8 -0.2 21.3 7 Mar 2021 1583.0 1117.1 high 142%
Ngayawili 32.0 -0.2 37.0 16 Nov 2020 24.8 +0.1 19.7 31 Oct 2020 1406.2 1365.4 average 103%
Warruwi Airport 32.5 +0.2 37.7 7 Nov 2020 25.8 +0.2 21.9 14 Dec 2020 980.0 1117.6 average 88%
Roper-Mcarthur (district 14DE)
Borroloola Airport 35.8 +0.4 44.1 25 Nov 2020 23.6 +0.2 12.6 24 Apr 2021 862.2 903.5 average 95%
Bulman 35.9 -0.2 42.8 26 Nov 2020     15.9 25 Apr 2021 1274.0 1049.0 average 121%
Daly Waters Airstrip 36.2 +0.1 43.3 26 Nov 2020 22.9 +0.2 11.6 14 Apr 2021 866.4 665.8 high 130%
McArthur River Mine Airport 36.6 -0.1 43.8 26 Nov 2020 23.8 +0.2 14.5 13 Apr 2021 847.0 766.4 average 111%
Ngukurr Airport 36.5   43.9 26 Nov 2020 24.3   13.9 24 Apr 2021 1111.8
Victoria (district 14F)
Bradshaw 36.8 0.0 42.7 2 Nov 2020 25.1 +0.4 14.0 25 Apr 2021 1299.4 925.6 high 140%
Bradshaw - Angallari Valley (Defence) 36.8   43.0 26 Nov 2020 24.9   14.0 25 Apr 2021 1123.6
Bradshaw - Koolendong Valley (Defence) 36.0   42.8 16 Nov 2020 23.3   9.2 25 Apr 2021 1158.0
Lajamanu Airport 36.3 -0.6 44.8 27 Nov 2020 23.0 +0.6 11.8 19 Apr 2021 688.6 484.4 high 142%
Victoria River Downs 36.7 +0.1 44.2 12 Nov 2020 24.0 +0.4 12.1 25 Apr 2021 813.1 645.1 high 126%
Wave Hill 36.9 +0.1 43.9 13 Nov 2020 23.5 +0.7 12.1 25 Apr 2021 616.9 648.4 average 95%
Barkly (district 15A)
Elliott 37.0 -0.2 44.3 12 Nov 2020 23.6 +0.8 13.8 14 Apr 2021 401.6 572.0 low 70%
Tennant Creek Airport 36.4 +1.0 43.2 13 Nov 2020 24.2 +0.8 16.2 13 Apr 2021
Alice Springs (district 15B)
Alice Springs Airport 33.1 -0.2 43.7 28 Nov 2020 18.2 +0.3 3.9 19 Apr 2021 275.6 217.6 high 127%
Jervois 35.4 0.0 46.0 5 Dec 2020 20.0 +0.6 7.5 13 Apr 2021 240.2 232.6 average 103%
Rabbit Flat 36.8 -0.7 45.2 28 Nov 2020     6.4 19 Apr 2021 563.0 435.8 high 129%
Territory Grape Farm 34.1 -0.9 43.5 28 Nov 2020 19.0 -0.3 7.1 30 Apr 2021 464.6 243.9 highest 190%
Walungurru Airport 35.9 -1.4 45.3 28 Nov 2020 23.9 +0.1 8.9 7 Oct 2020 254.4 234.5 average 108%
Yulara Airport 34.2 -0.7 45.2 28 Nov 2020 19.7 +0.6 5.3 7 Oct 2020 179.2 208.0 average 86%

Notes

The Seasonal 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 Tuesday 4 May 2021. 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