Northern Territory in April 2017: a wet month in the northeast and southwest corners; a record cold day in Darwin

April saw above average rainfall in the southwest due to a cloudband, and above average rainfall over the northeastern Top End. On the 11th the Top End experienced a highly unusual cold day. Tropical cyclone Frances formed on the 27th in the Timor Sea, moved southwest and did not make landfall over the Northern Territory.

Above average rainfall in the northeast and southwest corners of the Territory

  • The monsoon trough mostly remained over water north of Australia at the beginning of the month, dipping south briefly to affect some of the northern coast
  • Northeastern Arnhem Land received above average rainfall, with some locations receiving more than 400 mm during the month and a few sites having their wettest April rainfall for many years
  • A tropical low over northwestern Western Australia fed tropical moisture into the southwestern NT in the middle of the month, leading to above average rainfall over the Lasseter District: Walungurru Airport recorded 84.2 mm for April, well above the April average of 15 mm
  • Total April rainfall was about 12% above average for the NT

Record cold day in the Top End

  • Rain falling into cool, dry southeast winds saw Darwin record a maximum temperature of just 21.9°C on the 11th, its coldest April day on record, well below the previous wet season record of 24.0°C and the third-coldest day for any time of year
  • A number of other locations in the wider Darwin area also recorded their coldest April day (lowest maximum temperature) on record during this event
  • There were some cold nights inland at the end of the month, with two sites having their lowest April temperature on record
  • The Territory's mean daily maximum temperature was 0.43 °C above average, but the mean minimum temperature was 0.11 °C below average

End of wet season tropical cyclone

  • A tropical low formed into tropical cyclone Frances over the Timor Sea on the 27th, before moving away southwest into Western Australian waters

Further information

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Extremes in April 2017
Hottest day 40.0 °C at Watarrka on the 2nd
Warmest days on average 35.9 °C at Bradshaw
Coolest days on average 28.0 °C at Yulara Airport
Coldest day 19.6 °C at Arltunga on the 28th
Coldest night 3.5 °C at Alice Springs Airport on the 29th
Coolest nights on average 12.1 °C at Alice Springs Airport
Warmest nights on average 25.7 °C at Centre Island
Warmest night 27.6 °C at Centre Island and Jabiru Airport on the 9th, and McCluer Island on the 21st
Warmest on average overall 29.3 °C at Bradshaw
Coolest on average overall 20.4 °C at Alice Springs Airport
Wettest overall 509.8 mm at Alcan Minesite
Wettest day 222.4 mm at Warruwi Airport on the 11th
Strongest wind gust 85 km/h at McCluer Island on the 10th

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


Highest April total rainfall for at least 20 years
Observed
(mm)
Most recent
higher
Average for
April
Alcan Minesite 509.8 666.8 in 1983* 246.7
Cape Wessel 414.4 1061.2 in 1992* 161.5
Warruwi Airport 291.2 455.6 in 1996 118.8
Black Point 269.8 375.0 in 1995* 110.8

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




Record highest April temperature
New record
(°C)
Old
record
Years of
record
Average for
April
Watarrka 40.0 on the 2nd 39.0 on the 2nd in 2005 23 30.6



Record lowest April daily maximum temperature
New record
(°C)
Old
record
Years of
record
Average for
April
Darwin Airport 21.9 on the 11th 24.6 on the 10th in 1954 76 32.7
Pirlangimpi Airport 23.6 on the 11th 25.5 on the 17th in 1989 35 32.9
Douglas River 25.5 on the 11th 26.7 on the 25th in 2012 26 34.6
Black Point 25.8 on the 10th 26.0 on the 18th in 2001 25 31.8
Channel Point 25.8 on the 11th 26.5 on the 4th in 2006 23 32.5
Batchelor Airport 23.6 on the 11th 25.9 on the 25th in 2006 20 33.9



Record lowest April temperature
New record
(°C)
Old
record
Years of
record
Average for
April
Borroloola Airport 9.0 on the 30th = 9.0 on the 30th in 1999 23 20.3
Territory Grape Farm 4.9 on the 29th 5.0 on the 23rd in 2001 21 14.5



Summary statistics for April 2017
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
April
2017
Diff
from
average
Highest for
April
2017
Mean for
April
2017
Diff
from
average
Lowest for
April
2017
Total for
April
2017
Average
for
April
Rank of
April
2017
Fraction of
April
average
Darwin-Daly (district 14GA)
Batchelor Airport 32.7 -1.2 35.2 8th 22.4 +0.7 16.8 12th 6.4 88.3 low 7%
Black Point 30.7 -1.1 33.0 15th 24.9 -0.1 23.1 30th 269.8 110.8 v high 244%
Bradshaw 35.9 -0.2 38.2 9th 22.7 +0.4 16.9 30th
Central Arnhem Plateau 31.4 -1.1 33.9 5th 22.0 +0.4 18.7 30th 94.6 59.7 high 158%
Charles Point 32.0   35.1 8th 24.1   17.8 12th 181.6
Croker Island Airport 30.6   33.4 15th 24.7   22.7 30th 275.6
Darwin Airport 32.0 -0.7 34.2 8th 24.1 +0.1 18.0 12th 191.4 101.6 high 188%
Delamere Weapons Range 34.8 +0.7 37.6 8th 21.3 +0.2 15.1 30th 0.8 17.2 average 5%
Douglas River 33.9 -0.7 36.0 9th 21.5 +1.0 16.2 30th 64.4 49.8 high 129%
Dum In Mirrie Airstrip 32.1 -0.9 35.1 9th 23.9 -0.5 18.1 12th   87.6    
Jabiru Airport 33.6 -1.0 36.1 5th 24.7 +1.1 22.2 11th 162.4 88.8 high 183%
Katherine Country Club 34.0   36.0 6th 21.3   16.0 30th 22.2
McCluer Island 29.9 -1.0 31.6 5th 25.6 -0.5 24.2 11th 375.6 152.6 v high 246%
Middle Point 32.9 -1.4 34.9 8th 23.1 +0.7 18.5 12th 108.4 101.2 average 107%
Murganella Airstrip 31.1   34.1 5th 23.6   21.6 30th 279.8
Noonamah Airstrip 33.1   35.3 8th 23.1   17.7 12th 188.2
Oenpelli Airport 33.1   35.5 6th 24.3   21.6 30th 153.8
Pirlangimpi Airport 31.6 -1.3 35.1 8th 23.7 +0.6 20.7 12th 393.0 157.0 v high 250%
Point Fawcett 31.6 -0.8 34.0 3rd 23.4 -0.1 20.2 12th 316.6 141.7 high 223%
Point Stuart 31.8   33.3 8th     21.3 30th 46.8 124.6 low 38%
Port Keats Airport 33.6 -0.8 36.7 9th 23.3 +0.9 18.3 12th 89.4 82.2 average 109%
Tindal RAAF 34.0 0.0 36.0 7th 21.0 +0.4 15.0 30th 20.6 39.6 average 52%
Arnhem (district 14BC)
Cape Wessel 31.3   32.9 5th 25.5   24.0 24th 414.4 161.5 v high 257%
Gove Airport 30.8 -0.1 32.2 5th 24.2 +0.9 22.2 22nd 488.2 228.4 high 214%
Groote Eylandt Airport 32.3 -0.1 33.8 7th 22.7 +0.9 16.6 30th 177.8 150.6 average 118%
Maningrida Airport 31.2 -1.4 33.9 5th 23.4 0.0 20.1 29th 491.6 151.3 v high 325%
Milingimbi Airport 31.1 -1.3 33.7 5th 23.9 0.0 20.9 29th 442.4 135.0 v high 328%
Ngayawili 30.7 -1.2 32.9 6th 24.3 +0.6 22.0 30th 458.0 166.7 high 275%
Roper-Mcarthur (district 14DE)
Borroloola Airport 34.0 -0.1 35.8 24th 19.5 -0.8 9.0 30th 29.4 65.6 average 45%
Bulman 32.7 -1.5 34.9 6th 22.0 +1.3 16.7 29th 113.6 64.2 high 177%
Centre Island 32.7 +0.6 34.6 16th 25.7 +0.4 20.3 30th 13.8 94.4 average 15%
Daly Waters Airstrip 35.0 +1.1 37.4 6th 18.9 -0.7 10.8 30th 0.2 21.2 average 1%
McArthur River Mine Airport 35.2 +0.4 36.7 15th 21.1 +0.4 10.2 30th 0 31.1 lowest 0%
Ngukurr Airport 33.9   36.5 5th 21.9   13.8 30th 69.6
Victoria (district 14F)
Lajamanu Airport 34.5 +0.8 37.7 8th 18.9 +0.9 11.4 30th 0.4 15.2 average 3%
Victoria River Downs 34.6 0.0 36.5 23rd 20.0 +0.2 13.6 30th 5.0 22.4 average 22%
Wave Hill 34.1 -0.2 36.5 22nd 19.7 +0.9 11.7 30th 0 17.9 lowest 0%
Barkly (district 15A)
Brunette Downs 34.2 +0.6 37.0 25th 18.7 -0.5 10.0 30th 0 14.8 lowest 0%
Elliott 34.1 -0.4 36.7 7th 19.7 +0.1 11.4 30th 0 21.7 lowest 0%
Tennant Creek Airport 32.8 +1.1 35.9 9th 20.4 0.0 13.0 29th 0 16.7 lowest 0%
Alice Springs (district 15B)
Alice Springs Airport 28.7 +0.4 35.5 8th 12.1 -0.5 3.5 29th 0 17.0 lowest 0%
Curtin Springs 28.2 -1.0 36.4 8th 13.1 -0.5 7.5 12th 27.0 15.5 high 174%
Jervois 31.1 +0.6 36.2 24th 14.6 +0.2 7.3 28th 0 16.5 lowest 0%
Rabbit Flat 34.2 +0.2 37.7 23rd 16.9 +0.2 7.6 29th 0 21.2 lowest 0%
Territory Grape Farm 31.3 +0.7 35.6 8th 13.8 -0.7 4.9 29th
Walungurru Airport 30.8 -2.3 37.2 8th 18.3 -2.3 13.0 28th 84.2 15.3 high 550%
Yulara Airport 28.0 -1.8 36.8 8th 13.5 -0.9 9.1 11th 57.8 16.3 high 355%

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 12 pm on Tuesday 2 May 2017. 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
Enquiries