Northern Territory in October to April 2019-20: Low rainfall and very warm temperatures

Nearly the entire Northern Territory saw below average rainfall totals during the 2019-20 wet season. Both daytime and overnight temperatures both ranked as the second-highest on record as nearly all locations had temperatures in the highest 10% of their long-term record.

Back-to-back dry wet seasons

  • The Northern Territory had a second season of below average rainfall, immediately following a dry 2018-19 wet season. Territory-wide, rainfall was 20% below the long-term average. Only a few parts of the eastern NT saw average or above average rainfall for the wet season. The north-western, the far north, and the south-western NT, had seasonal rainfall totals in the lowest 10% of historical records since 1900.The primary climate driver responsible for the low rainfall was the near-record strong positive Indian Ocean Dipole (IOD) which dominated Australia during the second half of 2019
  • The positive IOD contributed to the late monsoon onset of 18 January, 3 weeks later than average. Following this initial monsoon activity, two other relatively weak and short-lived monsoon bursts were observed, contributing to moderate widespread rainfall over the NT. Below average tropical low/cyclone activity during 2019-20 also contributed to the relatively dry conditions
  • Despite the dry conditions, some sites in the western Top End had their highest daily October to April rainfall on record, as the tropical low which developed into TC Claudia passed to the north
  • Tropical cyclone Esther was responsible for some isolated heavy falls in late February, as the system first developed near the southern Gulf of Carpentaria coast, and looped across the NT and northern Western Australia mostly as an ex-tropical cyclone till early March

Very warm daytime and overnight temperatures throughout

  • The mean maximum temperature average across the Northern Territory during the October 2019 to April 2020 period was 2.13 °C above the long-term average. This was the second-highest on record, behind the wet season of 2018-19 (2.52 °C above average)
  • Virtually the entire Top End had record high mean maximum temperatures, while the remainder of the NT had mean maximum temperatures among the top 10% of all records
  • Many sites over the Top End, including Darwin, Tindal and Jabiru, along with Yulara in the southern NT, had their highest October to April mean daily maximum temperature on record
  • December was a notably warm month in 2019-20, with many sites, including Alice Springs, Tindal, Yulara and Borroloola having their highest October to April temperature on record during early December and around Christmas Day; some of these records were also annual high temperature records
  • Most of the Territory had mean minimum temperatures during the wet season that were in the top 20% of all records, with a significant proprtion exceeding the top 10% of records
  • Territory-wide, the mean minimum temperauture was 1.45 °C above the long-term average. This was the second-highest on record, behind only the wet season of 2018-19 (1.94 °C above average). The mean temperture across the NT was 1.79 °C above the long-term average; second-highest on record, behind the wet season of 2018-19 (2.23 °C above average)
  • Yulara, in the southern NT, had its highest October to April mean daily minimum temperature on record. Many sites, including Darwin, Tindal and Yulara had their warmest October to April night (highest daily minimum temperature) on record. These were recorded during the hot spell associated with the record high maximum temperatures during December 2019

Tropical cyclones

  • The Northern Territory was affected by two tropical cyclones during wet season 2019-20
  • A tropical low moved across the Top End before moving over the Timor Sea and became TC Claudia in the first half of January, and while no significant wind impacts were observed, the low generated very heavy rain across parts of the northwest Top End
  • TC Esther made landfall near the NT/Qld border in the southern Gulf of Carpentaria, late in February, generating heavy rainfall across parts of the Carpentaria, Daly and southern Arnhem districts. As an ex-TC, Esther subsequently tracked westwards through northern Western Australia and then through much of the central NT, in early March, generating locally heavy rainfall

Darwin Airport

  • Total rainfall for Darwin Airport was 1180.0 mm, which is 70% of the long-term average of 1676.1 mm. This is the first time on record that Darwin has had a successive sub-1200 mm rainfall total during a wet season
  • The mean daily maximum temperature for Darwin Airport was 33.9 °C, which is 1.4 °C above the long-term average of 32.5 °C and highest on record. The warmest day was 38.2 °C on 21 October, and the coolest day was on 9 March when the temperature reached 27.0 °C
  • The mean daily minimum temperature for Darwin Airport was 25.6 °C, which is 0.8 °C above the long-term average of 24.8 °C, and the highest since 1987. The coldest morning was 20.5 °C on 11 April, and the warmest morning was on 27 December when the minimum temperature was 30.2 °C (highest minimum temperature on record)

Alice Springs Airport

  • Total rainfall for Alice Springs Airport was 91.8 mm, which is 42% of the long-term average of 216.8 mm
  • The mean daily maximum temperature for Alice Springs Airport was 35.8 °C, which is 2.5 °C above the long-term average of 33.3 °C. The warmest day was 45.7 °C on the 25 December (highest temperature on record), and the coolest day was on 30 April when the temperature reached 19.4 °C
  • The mean daily minimum temperature for Alice Springs Airport was 19.4 °C, which is 1.5 °C above the long-term average of 17.9 °C. The coldest morning was 8.7 °C on 10 October, and the warmest morning was on 10 January when the minimum temperature was 31.0 °C

Further information

Media
(03) 9669 4057

Extremes in October to April 2019-20
Hottest day 47.9 °C at Rabbit Flat on 25 Dec 2019
Warmest days on average 39.1 °C at Lajamanu Airport
39.1 °C at Rabbit Flat
Coolest days on average 31.5 °C at McCluer Island
Coldest day 19.4 °C at Alice Springs Airport on 30 Apr 2020
19.4 °C at Yulara Airport on 30 Apr 2020
Coldest night 2.5 °C at Kulgera on 30 Apr 2020
Coolest nights on average 19.4 °C at Alice Springs Airport
Warmest nights on average 27.0 °C at McCluer Island
Warmest night 36.0 °C at Walungurru Airport on 26 Dec 2019
Warmest on average overall 32.4 °C at Walungurru Airport
Coolest on average overall 27.6 °C at Alice Springs Airport
Wettest overall 1726.1 mm at Wagait Beach
Wettest day 562.0 mm at Dum In Mirrie Airstrip on 11 Jan 2020
Strongest wind gust 117 km/h at Middle Point on 17 Dec 2019

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
Bullo River 226.0 on 28 Feb 2020 219.0 on 30 Oct 1975 36
Wagait Beach 515.2 on 11 Jan 2020 367.0 on 16 Feb 2011 33
Dum In Mirrie Airstrip 562.0 on 11 Jan 2020 345.6 on 20 Feb 2008 26



Record highest October to April temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Alice Springs Airport 45.7 on 25 Dec 2019 45.6 on 3 Jan 2019 79 33.3
Jervois 47.2 on 25 Dec 2019 = 47.2 on 22 Dec 1990 53 35.4
Daly Waters Airstrip 45.6 on 27 Dec 2019 44.5 on 15 Nov 2006 51 36.1
Kulgera 47.0 on 29 Dec 2019 = 47.0 on 3 Jan 2019 40 33.2
Tindal RAAF 43.1 on 6 Dec 2019 42.5 on 10 Nov 2006 34 35.3
Yulara Airport 47.1 on 24 Dec 2019 46.8 on 3 Jan 2019 34 34.9
Douglas River Research Farm 44.1 on 20 Oct 2019 42.6 on 20 Oct 2002 32 35.1
Watarrka 46.0 on 24 Dec 2019 = 46.0 on 30 Dec 2018 29 35.2
Borroloola Airport 44.7 on 26 Dec 2019 44.6 on 5 Dec 2018 27 35.3
Batchelor Airport 41.9 on 20 Oct 2019 41.8 on 16 Oct 2002 25 34.2
Delamere Weapons Range 43.6 on 6 Dec 2019 43.0 on 1 Dec 2006 24 35.6
Rabbit Flat 47.9 on 25 Dec 2019 47.1 on 19 Dec 2018 24 37.4
Point Fawcett 36.5 on 20 Dec 2019 36.3 on 8 Nov 2015 23 32.4
Port Keats Airport 41.0 on 10 Oct 2019 40.6 on 11 Nov 2015 21 33.6
Arltunga 44.5 on 25 Dec 2019 43.9 on 6 Jan 2004 20 33.1



Record lowest October to April daily maximum temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Bradshaw 22.0 on 10 Apr 2020 25.5 on 18 Feb 2011 22 36.7
Port Keats Airport 22.0 on 10 Apr 2020 25.0 on 1 Jan 2009 21 33.6



Record highest October to April mean daily maximum temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Darwin Airport 33.9 33.7 in 2015 77 32.5
Jabiru Airport 36.6 = 36.6 in 2015 39 35.0
Yulara Airport 37.2 = 37.2 in 2018 31 34.9
Tindal RAAF 38.0 36.8 in 2015 30 35.3
Douglas River Research Farm 36.7 36.2 in 2015 26 35.1
Borroloola Airport 37.9 37.5 in 2018 24 35.3
Point Fawcett 33.5 = 33.5 in 2015 20 32.4



Record highest October to April daily minimum temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Darwin Airport 30.2 on 27 Dec 2019 30.0 on 12 Dec 2018 80 24.8
Daly Waters Airstrip 31.3 on 27 Dec 2019 30.6 on 26 Nov 1965 51 22.7
Tindal RAAF 29.5 on 22 Nov 2019 29.3 on 7 Nov 1988 34 23.7
Yulara Airport 32.5 on 25 Dec 2019 32.0 on 18 Feb 2007 34 19.0
Black Point 30.4 on 27 Dec 2019 30.2 on 9 Dec 2009 29 25.6
Territory Grape Farm 31.1 on 26 Dec 2019 30.1 on 24 Jan 1988 28 19.2
Point Fawcett 30.1 on 27 Dec 2019 30.0 on 12 Jan 2003 23 24.9
Dum In Mirrie Airstrip 30.4 on 27 Dec 2019 30.2 on 21 Nov 2008 22 25.5
McCluer Island 30.3 on 27 Dec 2019 30.0 on 7 Dec 2018 22 26.6



Record lowest October to April temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Groote Eylandt Airport 11.8 on 13 Oct 2019 13.2 on 17 Oct 2014 21 23.7



Record highest October to April mean daily minimum temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Yulara Airport 20.9 = 20.9 in 2006 31 19.0

Highest October to April mean daily minimum temperature for at least 20 years
Observed
(°C)
Most recent
higher
Average for
October to April
Darwin Airport 25.6 25.7 in 1987 24.8



Record highest October to April mean temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Darwin Airport 29.7 29.5 in 2015 77 28.7
Yulara Airport 29.0 28.8 in 2018 31 26.9
Tindal RAAF 31.1 30.3 in 2018 30 29.5
Douglas River Research Farm 30.0 29.8 in 2015 26 29.1
Black Point 29.4 = 29.4 in 2015 25 28.8



Summary statistics for October to April 2019-20
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
October
to April
2019-20
Diff
from
average
Highest for
October
to April
2019-20
Mean for
October
to April
2019-20
Diff
from
average
Lowest for
October
to April
2019-20
Total for
October
to April
2019-20
Average
for
October
to April
Rank of
October
to April
2019-20
Fraction of
October
to April
average
Darwin-Daly (district 14GA)
Batchelor Airport 35.2 +1.0 41.9 20 Oct 2019 23.8 +0.3 19.1 11 Dec 2019 1171.4 1464.3 low 80%
Black Point 32.9 +0.8 35.2 18 Dec 2019 25.9 +0.3 19.9 17 Oct 2019 579.5 1193.6 lowest 49%
Central Arnhem Plateau 34.6 +1.2 40.3 7 Dec 2019 23.1 +0.2 17.0 22 Oct 2019 1016.4 1087.4 average 93%
Charles Point 32.4   35.4 23 Apr 2020 26.1   20.0 11 Apr 2020 1066.2
Croker Island Airport 32.9   36.1 21 Dec 2019 25.9   20.1 14 Oct 2019 941.6
Darwin Airport 33.9 +1.4 38.2 21 Oct 2019 25.6 +0.8 20.5 11 Apr 2020 1180.0 1676.1 v low 70%
Delamere Weapons Range 37.4 +1.8 43.6 6 Dec 2019 24.2 +0.5 18.8 10 Apr 2020 559.4 853.4 low 66%
Douglas River Research Farm 36.7 +1.6 44.1 20 Oct 2019 23.3 +0.2 16.7 15 Oct 2019 858.2 1265.1 v low 68%
Jabiru Airport 36.6 +1.6 42.3 19 Oct 2019 24.9 +0.4 19.3 14 Oct 2019 1069.4 1493.1 low 72%
Kangaroo Flats (Defence) 35.8   42.5 20 Oct 2019 24.5   19.8 11 Apr 2020 1408.2
McCluer Island 31.5 +0.2 34.7 17 Dec 2019 27.0 +0.4 22.5 14 Oct 2019 874.0 1080.7 low 81%
Middle Point 35.9 +1.1 42.5 20 Oct 2019 23.5 0.0 17.1 15 Oct 2019 1083.0 1315.1 low 82%
Mount Bundey North (Defence) 36.2   42.6 20 Oct 2019 24.6   21.5 17 Jan 2020 998.4
Mount Bundey South (Defence) 36.6   43.0 20 Oct 2019 24.7   19.7 27 Apr 2020 856.8
Murganella Airstrip 34.1   39.0 4 Dec 2019 23.4   14.4 14 Oct 2019 953.6
Noonamah Airstrip 35.5   41.6 20 Oct 2019 24.5   19.1 15 Oct 2019 1287.6
Oenpelli Airport 36.2   42.2 7 Dec 2019 24.5   15.9 15 Oct 2019 1291.8
Pirlangimpi Airport 33.4 +0.7 37.8 20 Oct 2019 24.4 +0.4 20.2 14 Oct 2019 1677.4 1929.0 average 87%
Point Fawcett 33.5 +1.1 36.5 20 Dec 2019 25.0 +0.1 17.1 14 Oct 2019 1075.0 1471.9 low 73%
Port Keats Airport 34.6 +1.0 41.0 10 Oct 2019 25.0 +0.5 19.2 11 Apr 2020 821.6 1234.1 low 67%
Tindal RAAF 38.0 +2.7 43.1 6 Dec 2019 24.1 +0.4 15.5 22 Oct 2019 457.2 1025.2 lowest 45%
Arnhem (district 14BC)
Cape Wessel 33.8   37.0 14 Dec 2019 26.2   21.4 12 Oct 2019 695.2 1052.5 low 66%
Gove Airport 33.2 +1.2 38.0 4 Dec 2019 24.4 +0.6 16.8 12 Oct 2019 567.2 1282.9 lowest 44%
Groote Eylandt Airport 34.5 +1.0 39.5 26 Dec 2019 23.4 -0.3 11.8 13 Oct 2019 726.6 1229.2 v low 59%
Maningrida Airport 33.6 +0.8 37.4 4 Dec 2019 24.5 +0.1 18.4 14 Oct 2019 974.4 1186.9 low 82%
Milingimbi Airport 34.1 +1.1 39.5 4 Dec 2019 25.0 0.0 18.8 13 Oct 2019 790.8 1089.7 low 73%
Warruwi Airport 33.0 +0.7 37.4 6 Dec 2019 26.1 +0.5 21.4 14 Oct 2019 965.4 1119.1 average 86%
Roper-Mcarthur (district 14DE)
Borroloola Airport 37.9 +2.6 44.7 26 Dec 2019 23.3 -0.1 13.7 13 Oct 2019 700.4 905.2 average 77%
Centre Island 34.7 +1.2 40.6 18 Jan 2020 26.6 +0.3 21.8 12 Oct 2019 881.4 1041.5 average 85%
Daly Waters Airstrip 38.1 +2.0 45.6 27 Dec 2019 22.8 +0.1 11.5 12 Oct 2019 555.6 661.8 average 84%
McArthur River Mine Airport 38.3 +1.6 44.1 26 Dec 2019 24.0 +0.4 14.3 12 Oct 2019 954.6 764.7 high 125%
Ngukurr Airport 38.5   44.0 15 Dec 2019 24.6   15.6 12 Oct 2019 727.0
Victoria (district 14F)
Bradshaw 38.5 +1.8 44.1 6 Dec 2019 25.7 +1.0 19.8 12 Oct 2019 613.8 906.0 low 68%
Bradshaw - Angallari Valley (Defence) 38.5   45.2 6 Dec 2019 25.7   19.9 10 Apr 2020 437.6
Bradshaw - Koolendong Valley (Defence) 37.6   44.1 6 Dec 2019 24.3   15.4 12 Oct 2019 999.4
Lajamanu Airport 39.1 +2.3 46.0 17 Dec 2019 23.8 +1.4 15.5 11 Oct 2019 349.4 480.5 average 73%
Victoria River Downs 38.5 +1.9 44.7 7 Dec 2019 24.1 +0.5 16.0 12 Oct 2019 529.8 641.7 average 83%
Barkly (district 15A)
Elliott 38.1 +0.9 45.1 17 Dec 2019 23.7 +1.0 16.0 29 Apr 2020 591.1 575.3 average 103%
Tennant Creek Airport 37.6 +2.2 44.5 24 Dec 2019 25.1 +1.7 18.3 29 Oct 2019 369.6 436.1 average 85%
Alice Springs (district 15B)
Alice Springs Airport 35.8 +2.5 45.7 25 Dec 2019 19.4 +1.5 8.7 10 Oct 2019 91.8 216.8 low 42%
Jervois 36.8 +1.4 47.2 25 Dec 2019 20.0 +0.6 8.4 10 Oct 2019 169.6 232.5 average 73%
Rabbit Flat 39.1 +1.7 47.9 25 Dec 2019 22.0 +0.5 11.8 11 Oct 2019 418.2 430.2 average 97%
Territory Grape Farm 36.7 +1.8 45.9 25 Dec 2019 20.4 +1.2 9.4 10 Oct 2019 198.0 236.0 average 84%
Walungurru Airport 39.0 +1.8 47.7 25 Dec 2019 25.7 +2.0 12.5 30 Apr 2020 39.6 233.4 v low 17%
Yulara Airport 37.2 +2.3 47.1 24 Dec 2019 20.9 +1.9 8.9 30 Apr 2020 46.6 209.0 v low 22%

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 10 am on Friday 1 May 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