Northern Territory wet season October to April 2016-17: wetter than average

  • Total rainfall was 48% above average, the eighth-highest on record
  • Mean maximum temperature 0.06 °C below average for the wet season
  • Mean minimum temperature 0.07 °C above average for the wet season
  • Monsoon onset for Darwin was 21 December
  • Three tropical cyclones formed in Northern Territory waters, but only ex-tropical cyclone Alfred made landfall over mainland Northern Territory
  • Darwin Airport recorded its third-wettest wet season on record
  • Darwin and some other sites had their coldest October to April day (lowest maximum temperature) on record on 11 April

During the "build up" months of October and November, temperatures were warmer than average for most of the Top End despite regular afternoon showers and thunderstorms. Severe thunderstorms impacted the Territory during November with widespread wind damage to vegetation in the Palmerston and Darwin River Dam regions on 5 December. The first half of December was very dry across all parts of the NT apart from the far south. The dry conditions were broken by the onset of the monsoon to the Top End on 21 December. A low combined with ex-tropical cyclone Yvette to form a tropical depression which tracked across inland Western Australia and central Australia, producing heavy rainfall and widespread flooding in the southern NT between 25 and 28 December. The first half of January saw a monsoon break, before the monsoon trough strengthened and impacted the Top End around 22 January. February began with the strongest monsoon burst of the wet season which was enhanced by a strong Madden-Julian Oscillation. The monsoon trough drifted further south and tropical cyclone Alfred formed in the Gulf of Carpentaria in mid-February. During the first week of March the monsoon became active again over northern Australia as tropical cyclone Blanche dragged the pre-existing monsoon trough south. In early April, Darwin recorded a maximum temperature of 21.9°C, significantly lower than the previous wet season record of 24.0°C. In the last week of the wet season tropical cyclone Frances formed in the Timor Sea and moved southwest into Western Australian waters. Darwin Airport's wet season rainfall total of 2484.4 mm was its third-highest on record.

Seasonal detail

October 2016: wet and hot in the north, cool in the south

A strong negative Indian Ocean Dipole in winter and spring, combined with warm waters to the north helped contribute to an early start to shower and storm activity across the Top End. Temperatures were above average over the Top End during the "build up" months of October and November. However Darwin Airport's maximum temperature only reached 26.7 °C on 22 October; its second-lowest October maximum temperature on record, as overnight thunderstorms left Darwin blanketed by thick cloud. The Top End had its highest number of severe thunderstorms during the build up, peaking in November.

November 2016: average rainfall throughout, warm in the north

The most significant events in November included widespread wind damage to vegetation in the Palmerston and Darwin River Dam regions on the 5th; a dust storm was reported in association with a severe wind gust of 96 km/h recorded at Alice Springs on the 11th, and small hail was reported at Howard Springs on the 16th (not actually a severe thunderstorm, but a rare occurrence).

December 2016 : wet throughout

The first half of December was very dry across all parts of the NT apart from the far south. The monsoon trough first formed in the Southern Hemisphere during the first week of December and became active over water north of Australia on 17 December. A tropical low developed off the NT's northwest coast on the 18th and tracked southwards, roughly parallel to the Territory's west coast, before crossing the northern Kimberley coast on the 21st.

As the monsoon trough drifted south and connected to the tropical low in the Kimberley from the 21st, widespread rainfall of between 50 mm and 200 mm fell across the Top End, with peak falls in excess of 400 mm reported along the west coast. The low combined with ex-tropical cyclone Yvette to form a tropical depression which tracked across inland Western Australia and Central Australia, producing heavy rainfall and widespread flooding in the southern NT between the 25th and 28th. This contributed to above average rainfall across the NT for December.

January 2017: wet throughout

January began with a monsoon break, before the monsoon trough strengthened and impacted the Top End around 22 January, delivering widespread rainfall totals between 50 mm to 150 mm, with peak falls exceeding 250 mm associated with a tropical low which tracked westwards across the base of the Top End. Further inland, a persistent tropical air mass brought well above average rainfall to much of the central and southern NT, leading to ongoing flooding in some parts.

Overall, the NT had a wetter than average January, with Territory-wide total rainfall almost twice the long term January average, and the eighth-wettest January on record. Minimum temperatures were slightly above average throughout the Territory, owing to above average cloud cover and humidity.

February 2017: wet in the north

February began with a monsoon burst that was enhanced by the Madden Julian Oscillation (MJO), although this was the only time during the wet season the MJO was at moderate strength as it passed through Australian longitudes. This was the strongest monsoon burst to hit the Top End this wet season. Darwin Airport recorded 201. 8 mm on the 5th, its 11th-highest daily total on record. Shoal Bay recorded 290. 0mm on the same day.

The monsoon trough drifted further south, with tropical cyclone Alfred forming in the Gulf of Carpentaria at mid-month. Alfred was the first tropical cyclone in the Northern Region since Nathan in March 2015. Moderate to heavy rainfall shifted to the eastern Carpentaria District, and Centre Island and Bing Bong Port had their highest total February rainfall on record, including 461. 2 mm between the 19th and 21st at Central Island. Maximum temperatures were below average across the base of the Top End and central parts of the Territory, owing to above average cloud cover and rainfall.

March 2017: dry in the south, hot throughout

During the first week of March the monsoon became active again over northern Australia as tropical cyclone Blanche dragged the pre-existing monsoon trough south. Blanche crossed the Kimberley coast on the 6th, the latest date for the first tropical cyclone landfall since reliable satellite records commenced in the 1970s. The previous record was TC Charlie on 1 March 1988. Point Fawcett, on the Tiwi Islands, recorded the highest rainfall observation during Blanche's passage with a 24-hour total of 384 mm. The monsoon trough quickly weakened after Blanche, as the passage of a relatively weak MJO did not significantly affect rainfall over northern Australia.

March saw above average maximum and minimum temperatures for most of the Territory; the Territory-wide mean temperature was the fourth-highest ever recorded, and highest since 1992, at 1.96 °C above the long-term average. Several sites in the southern half of the NT had their highest March mean daily maximum temperature on record, while Yulara had its highest March mean daily maximum temperature in the last 30 years. Alice Springs' mean daily maximum temperature was a new record and 4.2 °C above its March average.

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

The monsoon trough mostly remained over waters north of Australia at the beginning of April. It dipped south briefly to affect some of the northern coast for a day before dry air from Central Australia was directed into a tropical low, weakening the monsoon trough. The trough did not reform after this. Northeastern Arnhem Land received above average rainfall, with some locations receiving more than 400 mm during the month.

The Darwin area had an unusually cold day on the 11th. East to southeasterly winds brought dry air to the Top End, while a tropical low was located near the Tiwi Islands. During the day, widespread rain fell, causing evaporative cooling. This cold air was drawn over Darwi, which recorded a maximum temperature of 21.9 °C on the 11th, its coldest April day and its coldest wet season day on record, beating the previous wet season record of 24.0 °C. It was also the third-coldest maximum temperature on record for any time of year. A number of other locations also recorded their coldest April day on record during this event.

A tropical low formed to north of the Solomon Islands during the middle of April and slowly moved west into Northern Territory waters and strengthened. It was named tropical cyclone Frances on the 27th and moved southwest into Western Australian waters.

Further information

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Extremes in October to April 2016-17
Hottest day 44.7 °C at Rabbit Flat on 17 Dec 2016
Warmest days on average 36.7 °C at Rabbit Flat
Coolest days on average 31.4 °C at McCluer Island
Coldest day 19.6 °C at Arltunga on 28 Apr 2017
Coldest night 2.2 °C at Arltunga on 24 Oct 2016
Coolest nights on average 18.0 °C at Alice Springs Airport
Warmest nights on average 26.7 °C at McCluer Island
Warmest night 31.9 °C at Victoria River Downs on 10 Dec 2016
Warmest on average overall 30.7 °C at Bradshaw
Coolest on average overall 26.0 °C at Alice Springs Airport
Wettest overall 2727.5 mm at Channel Point
Wettest day 384.0 mm at Point Fawcett on 5 Mar 2017
Strongest wind gust 113 km/h at Centre Island on 20 Feb 2017

Maps
ObservedAnomalyDecile rank
Total
rainfall
Map of Rainfall totals Map of Percentage of normal rainfall Map of Rainfall deciles

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


Monthly maps
Rainfall rankMaximum temperature rankMinimum temperature rank
October 2016 Map of Rainfall deciles Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
November 2016 Map of Rainfall deciles Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
December 2016 Map of Rainfall deciles Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
January 2017 Map of Rainfall deciles Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
February 2017 Map of Rainfall deciles Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
March 2017 Map of Rainfall deciles Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
April 2017 Map of Rainfall deciles Map of Decile rank of mean maximum 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
Montejinni 212.0 on 2 Jan 2017 206.0 on 23 Jan 1987 47
Labelle Downs 275.0 on 24 Jan 2017 232.0 on 13 Jan 2004 31
Mulga Park 107.2 on 27 Dec 2016 89.8 on 13 Mar 1989 31
Point Fawcett 384.0 on 5 Mar 2017 265.2 on 16 Feb 2011 22
Charles Darwin University 260.0 on 6 Feb 2017 256.4 on 3 Jan 1997 20



Record highest October to April total rainfall
New record
(mm)
Old
record
Years of
record
Average for
October to April
Leanyer 2521.0 2441.2 in 1996 23 1784.4
Bullo River 1346.9 924.3 in 1993 21 733.6

Highest October to April total rainfall for at least 20 years
Observed
(mm)
Most recent
higher
Average for
October to April
Waterloo 1260.3 1266.4 in 1975* 659.4

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




Record highest October to April temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Borroloola Airport 44.2 on 6 Nov 2016 43.9 on 15 Nov 2006 24 35.1
Channel Point 37.7 on 7 Oct 2016 37.6 on 23 Oct 2008 23 32.1



Record lowest October to April daily maximum temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Darwin Airport 21.9 on 11 Apr 2017 24.0 on 17 Dec 1954 77 32.5
Pirlangimpi Airport 23.6 on 11 Apr 2017 25.5 on 17 Apr 1989 37 32.7
Batchelor Airport 23.6 on 11 Apr 2017 23.9 on 16 Feb 2011 22 34.2
Point Fawcett 23.1 on 11 Apr 2017 26.0 on 20 Oct 2000 20 32.3



Record highest October to April daily minimum temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Victoria River Downs 31.9 on 10 Dec 2016 31.5 on 27 Oct 1976 53 23.5



Record lowest October to April temperature
New record
(°C)
Old
record
Years of
record
Average for
October to April
Borroloola Airport 9.0 on 30 Apr 2017 = 9.0 on 30 Apr 1999 24 23.4



Summary statistics for October to April 2016-17
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
October
to April
2016-17
Diff
from
average
Highest for
October
to April
2016-17
Mean for
October
to April
2016-17
Diff
from
average
Lowest for
October
to April
2016-17
Total for
October
to April
2016-17
Average
for
October
to April
Rank of
October
to April
2016-17
Fraction of
October
to April
average
Darwin-Daly (district 14GA)
Batchelor Airport 33.5 -0.7 38.7 3 Nov 2016 23.7 +0.3 16.8 12 Apr 2017 1372.8 1500.7 average 91%
Bradshaw 36.4 -0.2 42.7 28 Nov 2016 25.1 +0.5 16.9 30 Apr 2017
Charles Point 32.1   35.1 8 Apr 2017 25.5   17.8 12 Apr 2017 2000.4
Darwin Airport 32.5 0.0 37.5 8 Oct 2016 25.0 +0.2 18.0 12 Apr 2017 2475.0 1684.3 v high 147%
Delamere Weapons Range 35.2 -0.2 41.5 7 Dec 2016 23.6 0.0 15.1 30 Apr 2017 1113.6 893.7 high 125%
Douglas River 34.8 -0.3 40.5 30 Oct 2016 23.3 +0.3 16.2 30 Apr 2017 1785.0 1278.6 high 140%
Dum In Mirrie Airstrip 32.4 +0.1 36.7 8 Oct 2016 25.5 0.0 18.1 12 Apr 2017 2350.0 1766.7 v high 133%
Jabiru Airport 34.8 -0.2 39.3 19 Oct 2016 25.0 +0.6 21.2 15 Oct 2016 1428.8 1501.1 average 95%
Katherine Country Club 35.7   41.5 13 Nov 2016 24.0   15.4 15 Oct 2016 1301.1
McCluer Island 31.4 +0.1 34.5 29 Nov 2016 26.7 +0.2 23.3 14 Nov 2016 1472.2 1088.0 high 135%
Middle Point 34.2 -0.6 38.9 16 Nov 2016 23.8 +0.4 18.5 12 Apr 2017 1691.8 1352.4 high 125%
Murganella Airstrip 32.8   36.4 29 Nov 2016 24.1   20.9 15 Oct 2016 1708.4
Noonamah Airstrip 33.8   38.4 3 Nov 2016 24.2   17.7 12 Apr 2017 2105.2
Oenpelli Airport 34.5   39.4 2 Nov 2016 24.7   19.7 15 Oct 2016 1626.2
Pirlangimpi Airport 32.9 +0.2 36.5 23 Feb 2017 24.4 +0.4 20.7 12 Apr 2017 2338.8 1929.8 high 121%
Point Fawcett 32.4 +0.1 36.0 8 Oct 2016 25.0 +0.2 20.2 12 Apr 2017 2133.8 1499.7 high 142%
Point Stuart 32.9   36.5 23 Feb 2017     21.3 30 Apr 2017 1720.0 1299.4 average 132%
Port Keats Airport 33.4 -0.2 39.0 5 Oct 2016 24.5 0.0 16.5 15 Oct 2016 2020.6 1248.0 high 162%
Tindal RAAF 35.4 +0.1 41.4 4 Nov 2016 23.9 +0.2 15.0 30 Apr 2017 1302.2 1055.1 high 123%
Arnhem (district 14BC)
Cape Wessel 33.0   36.6 3 Dec 2016 26.0   23.3 17 Feb 2017 1444.0 1048.9 high 138%
Gove Airport 32.2 +0.2 35.8 29 Nov 2016 24.6 +0.9 18.0 14 Oct 2016 1266.0 1301.7 average 97%
Groote Eylandt Airport 33.2 -0.3 38.8 13 Nov 2016 24.1 +0.5 14.3 14 Oct 2016 1531.0 1268.2 average 121%
Maningrida Airport 32.8 0.0 37.6 15 Nov 2016 24.5 +0.1 19.3 15 Oct 2016 1311.8 1226.1 average 107%
Milingimbi Airport 33.1 +0.2 37.2 15 Nov 2016 25.2 +0.3 19.9 14 Oct 2016 1688.0 1071.8 high 157%
Ngayawili 32.2 0.0 36.9 15 Nov 2016 25.1 +0.5 17.9 14 Oct 2016 1853.6 1415.2 high 131%
Roper-Mcarthur (district 14DE)
Borroloola Airport 35.3 +0.2 44.2 6 Nov 2016 23.4 0.0 9.0 30 Apr 2017 1192.2 930.5 high 128%
Bulman 35.3   40.9 11 Nov 2016 23.8   15.4 15 Oct 2016 1098.0 1120.7 average 98%
Centre Island 33.7 +0.3 39.5 12 Nov 2016 26.3 0.0 20.3 30 Apr 2017 1502.8 1053.4 high 143%
Daly Waters Airstrip 36.2 +0.2 43.1 7 Nov 2016 22.1 -0.6 10.8 30 Apr 2017 983.0 668.6 high 147%
McArthur River Mine Airport 36.1 -0.5 42.5 4 Nov 2016 24.2 +0.7 10.2 30 Apr 2017 1065.4 762.6 high 140%
Ngukurr Airport 36.1   42.7 9 Nov 2016 24.6   13.8 30 Apr 2017 1028.4
Victoria (district 14F)
Lajamanu Airport 36.6 +0.1 44.1 8 Nov 2016 22.5 +0.3 11.4 30 Apr 2017 599.0 490.0 high 122%
Victoria River Downs 36.1 -0.4 43.0 29 Nov 2016 23.7 +0.2 13.0 14 Oct 2016 964.6 645.8 v high 149%
Barkly (district 15A)
Brunette Downs 35.4 -1.0 42.2 6 Dec 2016 22.2 -0.5 10.0 30 Apr 2017 718.6 400.2 v high 180%
Elliott 35.8 -1.3 42.5 30 Nov 2016 23.0 +0.3 11.4 30 Apr 2017 868.9 583.3 high 149%
Tennant Creek Airport 35.2 -0.1 42.5 9 Nov 2016 22.9 -0.5 13.0 29 Apr 2017 651.9 447.1 high 146%
Alice Springs (district 15B)
Alice Springs Airport 34.1 +0.9 42.2 2 Dec 2016 18.0 +0.1 3.4 23 Oct 2016
Curtin Springs 34.3 0.0 42.0 26 Mar 2017 18.4 0.0 4.5 3 Oct 2016 339.6 172.5 high 197%
Jervois 35.3 0.0 43.7 2 Dec 2016 19.5 +0.2 6.6 18 Oct 2016 285.4 234.5 average 122%
Rabbit Flat 36.7 -0.5 44.7 17 Dec 2016 21.0 -0.4 7.6 29 Apr 2017 552.0 449.0 high 123%
Territory Grape Farm 34.5 -0.3 41.6 1 Dec 2016 18.5 -0.7 4.9 29 Apr 2017
Walungurru Airport 36.1 -0.9 43.4 9 Nov 2016     10.3 3 Oct 2016 655.8 259.1 v high 253%
Yulara Airport 34.4 -0.4 42.2 1 Dec 2016 18.7 -0.3 3.7 17 Oct 2016 362.0 218.6 high 166%

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 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