Northern Territory in October to April 2012-13: Dry, humid and hot

  • A late start to the North Australia Monsoon
  • Hottest October to April (northern wet season) on record: Alice Springs and Darwin
  • Gove Airport
    • driest start of a wet season on record
    • 300 mm below previous lowest by 1 March
    • ended as second driest on record
  • Easter weekend storm
    • set several new daily rainfall records
    • reduced rainfall deficit

October thunderstorm sets new Darwin daily rainfall record for northern suburbs

On the morning of Sunday 29 October, a slow moving trough crossed over the western Top End. The rainfall was a classic example of very localised heavy rainfall over Darwin as both the northern suburbs and the region from Humpty Doo to the Cox Peninsula received more than 40 mm while the Airport and the immediate suburbs to the south, including the city, missed out (The Airport recorded only 6 mm for the day). Leanyer managed to pick up 110.8 mm, their highest October daily total in 23 years worth of records.

Driest start of the wet season for Arnhem Land

Dry conditions dominated most of the Arnhem and the Roper - McArthur Districts in November and December. A persistent broad-scale area of very dry air which extended into the middle layers of the atmosphere for most of November and into December. This dry air prevented gulf lines from initiating convection over land. As gulf lines approached the Gove area from the east they would quickly dissipate before reaching the coast, leaving Gove and eastern Arnhem Land sorely dry. Gove Airport failed to register any rainfall during November, the second time in their record with 0.0 mm in November, the first being in 1994. By the end of November Gove Airport had only measured 7.8 mm of rain for the wet season, well under their October to November average of 55.6 mm. Farther south, Borroloola received 13.8 mm, their lowest November rainfall since 2006.

Following the dry November, December also saw low rainfall totals with a late monsoon onset. Gove Airport saw their second driest December on record with only 6.4 mm for the month, the long-term December average at Gove is 181.2 mm. Maningrida, Milingimbi, Ngayawili and Groote Eylandt Airport all had their driest October to December period on record.

Late onset of North Australian Monsoon

On average the North Australian Monsoon sets onto the Top End around the last week of December. This year, however, the monsoon did not arrive in December and rainfall totals for the month were lower than average for all of the Top End. Adelaide River Post Office, Pirlangimpi, Howard Springs Nature Park, and Darwin Hospital all saw their driest December on record. Leanyer, Karama, and Wagait Beach all saw their second driest December on record and it was mostly attributed to a lack of monsoon rainfall.

Beginning on 4 January, a monsoon trough formed off Australia's north coast, but it remained offshore due to a stationary high pressure area over the continent. Even as tropical cyclone Narelle moved south (off the WA northwest coast), from the 9th to the 14th, the high pressure over eastern Australia prevented the monsoon trough from moving over the continent. Beginning on the 15th, a surface based low pressure system formed over central Queensland and began moving to the northwest in the ensuing days. At the middle levels of the atmosphere the monsoon trough began shifting south to meet the surface low. This caused the onset of the North Australian Monsoon on the 17th of January. This came about three weeks later than usual, but still within the standard deviation of the the monsoon timing.

This first monsoon burst was quite brief across the Top End. By 19 January, two low pressure systems had formed over northeastern Australia within the monsoon trough, one over eastern Australia that would eventually become tropical cyclone Oswald and the other over northwestern Australia that would
eventually become tropical cyclone Peta. On the 21st tropical cyclone Oswald formed over the Gulf of Carpentaria and then made landfall on the western shores of the Cape York Peninsula. Over the next week ex-tropical cyclone Oswald moved south along the Queensland coast bringing high winds and
flooding rains to the area. In the meantime, on the 23rd, tropical cyclone Peta formed just of the northwest WA coast and tracked to the south west. With these two tropical systems to either side of the Northern Territory for the last week of January, the Top End experienced a lull in monsoon activity (scant rainfall and high temperatures) even under the influence of the monsoon trough.

March 2013: Wet weather finally arrives to the Top End

The wet season up to the end of February was hot and dry with many locations having the lowest wet season rainfall on record to that point in the season. In March, especially the last half of March, wet, monsoonal weather finally arrived in the Northern Territory and increased rainfall totals. The Madden-Julian Oscillation (MJO) was the main driver for the monsoon activity and general wet weather in the early part of the month. The MJO stalled over Australian longitudes which provided an extended period for a monsoon trough to form. Following another short break period mid-month, the passage of a westward moving equatorial Rossby wave during the last week of March revived the monsoon trough. A slow-moving, weak tropical low formed within the monsoon trough and moved along the north coast bringing heavy rainfall to most of the Top End (focused over the western Top End) during the Easter holiday weekend (28 March-1 April). This last burst of heavy rainfall lowered rainfall deficits across the northern NT. Many locations that were sitting below their previous lowest recorded wet season rainfall totals jumped above previous records, like Gove Airport, or closer to long-term means.

When comparing wet season (October to April) rainfall totals, the wettest overall was Geriatric Park with 1660.6 mm, followed by Edith Farms Road with 1646.1 mm, and then Walker Creek with 1613.6 mm. Meanwhile, The driest overall for the season was Bond Springs Turnoff with 46.5 mm, followed by Jervois with 70.4 mm, and then by Kulgera with 72.4 mm. Three sites had their lowest total October to April rainfall on record, these were Dum-In-Mirrie, Wagait Beach and Darwin Hospital. Dum-In-Mirrie and Wagait Beach recorded less than 1 metre of rainfall this season.

The wettest single day was at Mataranka Airstrip with 262.1 mm on 29 Mar 2013 (a new daily rainfall record for them), followed by Diljin Hill with 245.0 mm on 3 Mar 2013, and then Fergusson River with 239.0 mm on 30 Mar 2013.

Maximum temperature: Hottest wet season on record for many sites

Alice Springs Airport, Darwin Airport, Gove Airport, Jabiru Airport and Tindal RAAF, among other sites, all experienced their highest October to April mean daily maximum temperature on record. The hottest temperature reached anywhere in the NT this season was 46.7 °C at Walungurru with on 9 Jan 2013, and at Rabbit Flat on 25 Jan 2013. This set a new high October to April temperature record for both of these site where the previous records were 46.2 °C at Walungurru set on 28 January 2011 and 46.3 °C at Rabbit Flat set on 6 December 2004. Walungurru had a few days near this record with 46.6 °C on 8 Jan 2013 and again on 16 Jan 2013. This came at at time when several locations in the Alice Springs district were experiencing a prolonged heatwave. Walungurru endured 17 consecutive days above 42 °C from 1 January to 17 January 2013 of which 5 consecutive days were above 45 °C from 7 January to 11 January, inclusive. When averaged across the whole season, the warmest days on average were at Rabbit Flat with 38.7 °C, followed by Walungurru with 38.4 °C, followed by Brunette Downs with 37.9 °C. Victoria River Downs saw their warmest wet season in 21 years with a mean daily maximum temperature of 37.6 °C.

January was exceptionally hot across the NT (as well as the entire country). January set a new record for mean temperature, reaching 38.9 °C (both night-time and daytime temperatures combined) and also for the highest mean maximum temperature on record with 32.0 °C, which is 2.6 °C above the norm. Both existing records for the NT were set in 1971. Across the territory, 13 stations recorded their hottest January on record for mean temperatures. Such records were driven primarily by an strong sub-tropical ridge which included a hot, dry airmass that moved slowly across the continent resulting in really hot daytime temperatures. Of the 13 stations that recorded their highest mean maximum temperatures for the month, 12 of them also measured their hottest January daily maximum temperature. Gove with a mean maximum temperature of 33.3 °C, Tindal with 36.7 °C and Yulara with 41.3 °C were among the stations that broke their January record.

With a maximum temperature of 46.4 °C on the 11th (amidst the heat wave that perdured in the first half of the month), Yulara Aero equaled its hottest January day on record set in 2011. This was 0.6 °C shy of the hottest day ever recorded in Yulara for any given month. Further north, Tennant Creek hit the 44.2 °C mark on the 25th, making it the hottest January day in 44 years worth of records.

There were no low maximum temperature records set this season, but the coolest days on average were at McCluer Island with 31.6 °C, followed by Darwin Harbour with 32.5 °C, and then Ngayawili and Point Fawcett with 32.8 °C. The coldest days, this season, all occurred in the Alice Springs District in the last week of March as a passing cold front clipped the southern border of the NT. Yulara Aero saw the coolest daily maximum temperature 16.4 °C on 30 Mar 2013, followed by Kulgera with 18.2 °C on 28 Mar 2013, and then Curtin Springs with 19.0 °C on 30 Mar 2013.

An exceptional heat wave in early January

A heat wave early in January was exceptional in its extent and duration affecting most of Australia. In the southern NT, Alice Springs broke the record for the longest streak of days above 40 °C. From the 1st to the 17th inclusive, daytime temperatures at the Alice Springs airport rose over the 40 °C mark, surpassing the previous record streak of 12 days over 40 °C set in 2006. Although Alice Springs failed to break the record of the hottest January day set in 1960 with 45.2 °C, it manage to break the January mean maximum temperature record with 40.1 °C. This is 0.1 degrees warmer than the previous record of 40.0 °C set in January 2006. To the south of Alice Springs, Yulara Aero surpassed the 44.0 °C mark 10 days in a row (4th to the 13th inclusive), breaking their previous record streak of days above 44.0 °C of four days set in 1998. Walungurru endured 17 consecutive days above 42 °C from 1 January to 17 January 2013 of which 5 consecutive days were above 45 °C from 7 January to 11 January, inclusive.

Minimum temperature

October was the only month to see generally below average minimum temperatures this season. For all other months the mean daily minimum temperatures were above average to very much above average, with a few new high minimum temperature records. Jabiru experienced their highest October to April mean daily minimum temperature on record with a mean daily minimum of 25.0 °C, passing the previous record of 24.9 set in the 2006/2007 wet season. Walungurru tied their previous highest wet season minimums with a mean daily minimum of 24.6 °C.

January 2013 was an especially warm month for minimum temperatures. The January mean daily minimum for the whole of the NT was 25.0 °C. Although this is only, 1.3 °C above the norm, 12 stations across the Territory managed to register their warmest January nights on record. On average, nights in January 2013 were the warmest since January 2008. Particularly warm, was the night preceding Australia Day (26 January) in which Jabiru, Gove, Tindal, Batchelor and Middle Point recorded their warmest January night on record. It was also on this night (preceding 26th of January 2013) that four Top End sites all measured their warmest wet season (October to April) night on record. These were: Mango Farm with 28.0 °C (previous record 27.4 °C, 6 January 1998), Batchelor Aero with 27.8 °C (previous 27.1 °C, 6 January 1998), Groote Eylandt Airport 30.2 °C (previous record 30.0 °C, 3 December 2007), and Middle Point with 27.6 °C (previous record 27.0 °C, 29 January 2006).

Although not new records, the warmest nights this wet season were at Walungurru with 32.8 °C on 22 Jan 2013, followed by Jervois with 32.5 °C on 12 Jan 2013, and then again at Walungurru with 32.1 °C on 24 Jan 2013. The warmest nights on average for this wet season were at McCluer Island with 26.9 °C, followed by Cape Don with 26.8 °C, and then Centre Island and East Island with 26.5 °C.

While no records were set for low minimum temperatures, this season, the coldest night was at Alice Springs Airport with 4.0 °C on 13 Oct 2012, followed by Arltunga with 4.1 °C on 27 Apr 2013, and again at Arltunga with 4.8 °C on 13 Oct 2012. The coolest nights on average were at Alice Springs Airport with 18.4 °C, followed by Arltunga with 19.0 °C, and then Kulgera with 19.2 °C.

Wind

The strongest wind gust was measured at Lajamanu with 107 km/h on 18 Feb 2013, followed by Cape Wessel with 106 km/h on 20 Jan 2013.

Further information

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Extremes in October to April 2012-13
Hottest day 46.7 °C at Walungurru on 9 Jan 2013
46.7 °C at Rabbit Flat on 25 Jan 2013
Warmest days on average 38.7 °C at Rabbit Flat
Coolest days on average 31.6 °C at McCluer Island
Coldest day 16.4 °C at Yulara Aero on 30 Mar 2013
Coldest night 4.0 °C at Alice Springs Airport on 13 Oct 2012
Coolest nights on average 18.4 °C at Alice Springs Airport
Warmest nights on average 26.9 °C at McCluer Island
Warmest night 32.8 °C at Walungurru on 22 Jan 2013
Warmest on average overall 31.5 °C at Walungurru
Coolest on average overall 26.6 °C at Arltunga
Wettest overall 1660.6 mm at Geriatric Park
Driest overall 46.5 mm at Bond Springs Turnoff
Wettest day 262.1 mm at Mataranka Airstrip on 29 Mar 2013
Highest wind gust 107 km/h at Lajamanu on 18 Feb 2013


Maps
ObservedAnomalyDecile rank
Total
rainfall
Map of Rainfall totals Map of Rainfall Anomaly Map of Rainfall Decile

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

Month by month
Rainfall rank Maximum temperature rank Minimum temperature rank
October
Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
November
Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
December
Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
January
Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
February
Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
March
Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
April
Map of decile rank of rainfall Map of Decile rank of mean maximum temperature Map of Decile rank of mean minimum temperature
Rainfall rank Maximum temperature rank Minimum temperature rank

 


Record highest October to April daily rainfall
Highest daily rainfall
in October to April 2012-13 (mm)
Previous wettest
for October to April
Years of
record
Dorisvale 226.0 on 30 Mar 2013 201.0 on 2 Mar 2000 30
Mataranka Airstrip 262.1 on 29 Mar 2013 179.0 on 26 Jan 1998 27
Walker Creek 197.4 on 4 Mar 2013 178.8 on 19 Feb 2008 21
Upper Waterhouse River 182.4 on 31 Mar 2013 136.6 on 5 Apr 2006 15
Cave Creek Station 202.0 on 29 Mar 2013 135.0 on 30 Oct 2010 11
Coodardie 201.0 on 29 Mar 2013 138.0 on 24 Dec 2008 11



Record lowest total October to April rainfall
Total rainfall
for October to April 2012-13 (mm)
Previous driest
for October to April
Years of
record
Average for
October to April
Dum In Mirrie AWS 928.0 1095.6 in 2001 14 1730.6
Darwin Hospital 1178.0 1240.8 in 2001 11 1709.8
Wagait Beach 953.9 1107.4 in 1989 11 1776.6



Record highest October to April temperature
Highest temperature
in October to April 2012-13 (°C)
Previous warmest
for October to April
Years of
record
Average for
October to April
Curtin Springs 46.4 on 11 Jan 2013 46.0 on 17 Feb 1992 49 34.2
Watarrka 45.3 on 12 Jan 2013 = 45.3 on 21 Dec 1990 23 34.9
Rabbit Flat 46.7 on 25 Jan 2013 46.3 on 6 Dec 2004 17 37.1
Walungurru 46.7 on 9 Jan 2013 46.2 on 28 Jan 2011 12 36.8



Record highest October to April mean daily maximum temperature
Mean daily maximum
temperature
for October to April 2012-13 (°C)
Previous warmest
for October to April
Years of
record
Average for
October to April
Alice Springs Airport 35.7 35.4 in 2004 70 33.2
Darwin Airport 33.3 = 33.3 in 2004 70 32.4
Jervois 36.8 36.7 in 2004 40 35.2
Centre Island 34.4 34.3 in 2004 37 33.3
Gove Airport 33.0 32.6 in 1989 32 31.9
Jabiru Airport 36.1 36.0 in 2004 32 34.9
Kulgera 34.6 34.5 in 2006 31 32.9
Yulara Aero 36.4 36.1 in 2004 24 34.6
Tindal RAAF 36.2 = 36.2 in 1987 23 35.1
Douglas River 35.9 = 35.9 in 2004 19 34.9
Borroloola 36.2 35.9 in 2001 18 35.0
Dum In Mirrie AWS 32.9 32.5 in 2009 13 32.1
Ngayawili 32.8 32.5 in 2001 13 32.1
Point Fawcett 32.8 32.6 in 2002 13 32.1
Arltunga 34.3 34.2 in 2004 11 32.8
Middle Point AWS 35.6 35.2 in 2004 11 34.5



Record highest October to April daily minimum temperature
Highest daily minimum
temperature
in October to April 2012-13 (°C)
Previous warmest
for October to April
Years of
record
Average for
October to April
Mango Farm 28.0 on 26 Jan 2013 27.4 on 6 Jan 1998 33 23.2
Batchelor Aero 27.8 on 26 Jan 2013 27.1 on 6 Jan 1998 18 23.4
Groote Eylandt Airport AWS 30.2 on 26 Jan 2013 30.0 on 3 Dec 2007 14 23.6
Middle Point AWS 27.6 on 26 Jan 2013 27.0 on 29 Jan 2006 12 23.5



Record highest October to April mean daily minimum temperature
Mean daily minimum
temperature
for October to April 2012-13 (°C)
Previous warmest
for October to April
Years of
record
Average for
October to April
Jabiru Airport 25.0 24.9 in 1997 33 24.4
Walungurru 24.6 = 24.6 in 2006 10 23.5



Summary statistics for October to April 2012-13
Maximum temperatures
for October
to April
(°C)
Minimum temperatures
for October
to April
(°C)
Rainfall
for October
to April
(millimetres)
Mean for
October
to April
2012-13
Diff
from
average
Highest for
October
to April
2012-13
Mean for
October
to April
2012-13
Diff
from
average
Lowest for
October
to April
2012-13
Total for
October
to April
2012-13
Average
for
October
to April
Rank of
October
to April
2012-13
Fraction of
October
to April
average
Darwin-Daly (district 14GA)
Batchelor Aero 34.4 +0.4 38.6 4 Nov 2012 23.5 +0.1 16.2 13 Apr 2013 1409.8 1555.5 average 91%
Bradshaw 37.2 +0.9 42.3 7 Dec 2012 24.6 +0.1 15.6 3 Oct 2012 997.4 935.6 average 107%
Cape Don 33.6   36.9 7 Dec 2012 26.8   22.9 28 Jan 2013 1242.2 1226.9 average 101%
Central Arnhem Plateau 33.9   39.9 6 Dec 2012 22.9   16.3 2 Oct 2012 1168.2
Croker Island Airport 32.9   36.3 11 Dec 2012 25.7   20.5 14 Mar 2013 1247.6
Darwin Airport 33.3 +0.9 36.6 13 Oct 2012 25.0 +0.2 19.4 13 Apr 2013 1399.3 1682.8 low 83%
Darwin NTC AWS 32.5   35.3 27 Nov 2012 26.0   20.4 3 Dec 2012
Douglas River 35.9 +1.0 40.9 27 Oct 2012 23.1 +0.1 14.6 27 Apr 2013 980.4 1261.2 low 78%
Dum In Mirrie AWS 32.9 +0.8 36.0 25 Apr 2013 25.5 +0.1 18.4 13 Apr 2013 928.0 1730.6 lowest 54%
Jabiru Airport 36.1 +1.2 40.5 31 Oct 2012 25.0 +0.6 19.5 13 Apr 2013 1193.4 1523.7 low 78%
Katherine Country Club 36.6   41.3 6 Dec 2012 23.8   14.8 27 Apr 2013 1071.5
Mango Farm 35.1 +0.3 39.8 10 Oct 2012 23.4 +0.2 15.3 3 Oct 2012 1217.6 1374.8 average 89%
McCluer Island 31.6   34.6 19 Dec 2012 26.9   22.4 14 Mar 2013 1089.6 1131.7 average 96%
Middle Point AWS 35.6 +1.1 39.5 27 Nov 2012 23.2 -0.3 15.1 13 Apr 2013 919.4 1379.7 v low 67%
Noonamah AWS 35.4   39.1 27 Oct 2012 23.6   16.0 13 Apr 2013 1264.0
Oenpelli Airport 35.6   40.8 4 Dec 2012 24.4   17.9 2 Oct 2012 1132.6
Pirlangimpi 33.4 +0.9 36.7 4 Dec 2012 24.3 +0.4 20.3 14 Apr 2013 1575.6 1937.8 low 81%
Point Fawcett 32.8 +0.7 35.2 9 Dec 2012 24.5 -0.4 18.6 27 Apr 2013 995.2 1500.1 v low 66%
Tindal RAAF 36.2 +1.1 41.0 1 Nov 2012 23.8 +0.1 15.0 30 Apr 2013 1068.2 1062.1 average 101%
Arnhem (district 14BC)
Cape Wessel 33.1   36.6 10 Jan 2013 26.1   21.3 14 Mar 2013
Gove Airport 33.0 +1.1 36.2 25 Jan 2013 23.7 0.0 17.7 6 Oct 2012 855.8 1300.9 v low 66%
Groote Eylandt Airport AWS 34.0 +0.7 38.1 25 Jan 2013 23.7 +0.1 15.0 2 Oct 2012 1031.4 1326.5 low 78%
Maningrida Aero 33.4   36.9 25 Jan 2013 24.6   16.9 2 Oct 2012 947.4
Ngayawili 32.8 +0.7 36.3 2 Dec 2012 24.8 +0.2 19.9 13 Apr 2013 1004.2 1482.8 low 68%
North East Island 33.1   35.5 14 Jan 2013 26.5   22.5 3 Oct 2012 752.0 815.3 average 92%
Roper-Mcarthur (district 14DE)
Borroloola 36.2 +1.2 43.3 6 Dec 2012 23.5 +0.2 13.7 14 Oct 2012 842.6 938.8 average 90%
Centre Island 34.4 +1.1 39.7 27 Jan 2013 26.5 +0.2 22.0 12 Oct 2012
Daly Waters AWS 37.5 +1.6 43.4 25 Jan 2013 22.4 -0.3 9.9 14 Oct 2012 583.0 649.4 average 90%
McArthur River Mine 37.6 +1.1 44.1 6 Dec 2012 24.3 +0.9 11.7 14 Oct 2012 607.6 751.9 average 81%
Ngukurr AWS 37.5   43.7 6 Dec 2012 24.9   16.5 14 Oct 2012 664.4
Wollogorang     42.5 28 Jan 2013 22.2 -0.3 10.0 14 Oct 2012
Victoria (district 14F)
Timber Creek 37.4 +0.9 43.0 7 Dec 2012 24.2 +0.1 13.9 29 Apr 2013 719.5 955.0 low 75%
Victoria River Downs 37.6 +1.2 43.8 7 Dec 2012 23.5 0.0 11.3 16 Oct 2012 543.1 640.9 average 85%
Barkly (district 15A)
Brunette Downs 37.9 +1.5 42.9 7 Mar 2013 23.1 +0.4 11.5 13 Oct 2012 244.9 392.5 low 62%
Tennant Creek Airport 36.8 +1.6 44.2 25 Jan 2013 23.7 +0.4 14.2 12 Oct 2012 332.6 441.6 average 75%
Alice Springs (district 15B)
Alice Springs Airport 35.7 +2.5 44.4 12 Jan 2013 18.4 +0.5 4.0 13 Oct 2012 129.2 218.3 low 59%
Arltunga 34.3 +1.5 43.2 12 Jan 2013 19.0 +0.7 4.1 27 Apr 2013 121.8 239.6 low 51%
Curtin Springs 36.0 +1.8 46.4 11 Jan 2013 20.0 +1.7 6.0 3 Oct 2012 104.5 171.4 average 61%
Jervois 36.8 +1.6 45.5 11 Jan 2013 21.1 +1.9 8.4 13 Oct 2012 70.4 237.1 v low 30%
Kulgera 34.6 +1.7 44.9 8 Jan 2013 19.2 +0.8 5.3 2 Oct 2012 72.4 195.1 v low 37%
Rabbit Flat 38.7 +1.6 46.7 25 Jan 2013 21.7 +0.3 7.8 3 Oct 2012 276.0 440.2 average 63%
Walungurru 38.4 +1.6 46.7 9 Jan 2013 24.6 +1.1 13.8 11 Oct 2012 133.0 213.7 average 62%
Yulara Aero 36.4 +1.8 46.4 11 Jan 2013 20.2 +1.4 6.3 3 Oct 2012 86.8 220.8 low 39%

Notes

A Seasonal Climate Summary is prepared to list 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. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review, usually published in the fourth week of the month.

This statement has been prepared based on information available at 2 pm on Thursday 2 May 2013. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

Averages 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.

The ACORN-SAT dataset is being used for temperature area averages from December 2012 onwards. The major change from earlier datasets is that the ACORN-SAT dataset commences in 1910, rather than 1950, and hence rankings are calculated using a larger set of years.

Further information

Media
(03) 9669 4057
Enquiries