Friday, 1 March 2013 - Seasonal Climate Summary for South Australia - Product code IDCKGC13R0
Extremes Maps Records Summaries Important notes the top
Rainfall for the summer 2012-13 period across South Australia was widely below average. Across the state as a whole, it has been the driest summer since the summer of 1985-86 with rainfall only 41% of the summer average. This dry summer comes on the end of the third driest spring on record for South Australia, and prolonged dry conditions across central and northern South Australia since April 2012.
Rainfall totals were below average across much the State during December and January, February saw average to above average rainfall owing to a broad upper level trough which brought widespread rainfall at the end of the month.
The most significant rainfall event for summer occurred at the end of February. An upper level produced rainfall across most districts, resulted in daily rainfall totals in excess of 30 mm for several locations around the State. Beltana Roadhouse, in the Far North Pastoral, reported 50.4mm in the 24 hours to 9 am on February 28, which was the wettest day during summer for any location in South Australia.
Rainfall totals for summer as a whole were below average in the pastoral districts, with most locations areas in the Far North District receiving less than 40% of their long-term summer average. Rainfall totals ranged between 15 to 40mm, though some locations reported record lowest summer rainfall. Oodnadatta, in the Far North, observed just 3.6 mm over the summer period, against the summer average of 72.0 mm.
Rainfall totals in the agricultural districts were average to below average, while parts of the lower southeast saw very much below average rainfall throughout summer. Only the far western agricultural and parts of the Flinders Ranges saw near normal rainfall for the summer period. Rainfall totals ranged from 20 mm to 40 mm in the Western Agricultural, increasing to about in excess of 60 mm across the Flinders Ranges. The wettest location in the Agricultural districts was at Yongala in the Flinders Ranges with 91.4 mm.
Some sites had their lowest total summer rainfall on record. Some sites had their lowest total summer rainfall for at least 25 years. See a map of rainfall deciles.Temperatures across South Australia were widely above average during summer. Averaged across the State as whole, the summer daily average temperature for South Australia was 1.5 °C warmer than the long term summer average, the fourth warmest on record and the highest since the summer of 2005/2006. By comparison, summer 2011/2012 was just 0.1 °C warmer than average.
Maximum temperatures were well above across most of South Australia as a whole during the summer period. A prolonged heatwave event from late December and the first 3 weeks of January when temperatures were 4 °C or more warmer than average for a prolonged period, contributed strongly to the warmer than average summer days. For the state as a whole, summer daytime temperatures were the second hottest on record after summer 2000/01, with daytime temperatures 2.1 °C above normal for summer across the state.
Average maximum temperatures ranged from 22.6 °C at Cape Willoughby on Kangaroo Island to 39.8 °C at Moomba Airport in the Far North. The hottest day for any location in the state occurred on January 12 at Moomba Airport where the maximum reached with 49.6°C which was the highest temperature recorded in South Australia since 1960 and the sixth hottest temperature ever officially recorded in Australia. Also, Oodnadatta, in the far north of South Australia, observed a record run of 7 consecutive days with maximum temperatures above 45 °C. Further details on this event are available in Special Climate Statement 43.
See a map of maximum temperature anomalies.
Averaged across the State as a whole, minimum temperatures were 0.9 °C warmer than normal. Minimum temperatures ranged from 11.3 °C at Naracoorte Aerodrome in the southeast to 23.6°C at Moomba Airport in the Far North. The lowest recorded minimum temperature was 2.1°C at Naracoorte Aerodrome on December 10 and the warmest night was 32.4 °C at Arkaroola in the Far North on January 18.
See a map of minimum temperature anomalies.
Some sites had their highest summer temperature on record. Some sites had their highest summer mean daily maximum temperature on record. Some sites had their highest summer mean daily maximum temperature for at least 25 years. Some sites had their highest summer mean daily minimum temperature on record.
| Extremes in summer 2012-13 | |
|---|---|
| Hottest day | 49.6 °C at Moomba Airport on 12 Jan 2013 |
| Warmest days on average | 39.8 °C at Moomba Airport |
| Coolest days on average | 22.6 °C at Cape Willoughby |
| Coldest day | 13.9 °C at Mount Lofty on 3 Dec 2012 |
| Coldest night | 2.1 °C at Naracoorte Aerodrome on 10 Dec 2012 |
| Coolest nights on average | 11.3 °C at Naracoorte Aerodrome |
| Warmest nights on average | 23.6 °C at Moomba Airport |
| Warmest night | 32.4 °C at Arkaroola on 18 Jan 2013 |
| Warmest on average overall | 31.7 °C at Moomba Airport |
| Coolest on average overall | 18.8 °C at Robe Airfield |
| Wettest overall | 91.4 mm at Yongala |
| Driest overall | 3.6 mm at Oodnadatta Airport |
| Wettest day | 54.2 mm at Beltana Roadhouse on 28 Feb 2013 |
| Highest wind gust |
107 km/h at Marree Aero on 1 Dec 2012 107 km/h at Neptune Island on 25 Jan 2013 |
Extremes Maps Records Summaries Important notes the top
| Record lowest total summer rainfall | |||||
|---|---|---|---|---|---|
|
Total rainfall for summer 2012-13 (mm) |
Previous driest for summer |
Years of record |
Average for summer |
||
| Coonawarra | 26.2 | 30.4 | in 1998 | 27 | 85.4 |
| Moonaree (Kangaroo Well) | 5.2 | 9.1 | in 1987 | 26 | 50.6 |
| Lowest total summer rainfall for at least 25 years | |||||
|---|---|---|---|---|---|
|
Total rainfall for summer 2012-13 (mm) |
Most recent summer at least this dry |
Years since drier |
Average for summer |
||
| Oodnadatta Airport | 3.6 | 2.6 | in 1955* | 47 | 72.0 |
| Minlaton | 13.8 | 12.4 | in 1982 | 30 | 48.7 |
| Alawoona | 19.8 | 5.9 | in 1984 | 28 | 58.5 |
| Mount Barry Station | 6.6 | 0.0 | in 1985* | 25 | 71.7 |
| Port Elliot Caravan Park | 20.8 | 12.6 | in 1984* | 25 | 62.9 |
| Tarcoola (Commonwealth Hill) | 14.3 | 4.2 | in 1985* | 25 | 56.1 |
* note: there are gaps in the historical record at this site, so it is possible a lower value has gone unreported.
| Record highest temperature | ||||||
|---|---|---|---|---|---|---|
| Highest temperature | Previous warmest | Years of record |
Average for summer |
|||
| Mount Gambier Aero | 43.6 | on 4 Jan 2013 | = 43.6 | on 29 Jan 2009 | 72 | 24.4 |
| Adelaide Airport | 44.1 | on 4 Jan 2013 | 44.0 | on 28 Jan 2009 | 59 | 27.3 |
| Kimba | 46.0 | on 4 Jan 2013 | 45.6 | on 31 Jan 1968 | 46 | 30.6 |
| Leigh Creek Airport | 46.3 | on 6 Jan 2013 | 46.1 | on 25 Jan 2011 | 30 | 34.3 |
| Record highest summer mean daily maximum temperature | |||||
|---|---|---|---|---|---|
|
Mean daily maximum temperature for summer 2012-13 (°C) |
Previous warmest for summer |
Years of record |
Average for summer |
||
| Neptune Island | 23.1 | = 23.1 | in 2000 | 47 | 21.6 |
| Highest summer mean daily maximum temperature for at least 25 years | |||||
|---|---|---|---|---|---|
|
Mean daily maximum temperature for summer 2012-13 (°C) |
Most recent summer at least this warm |
Years since warmer |
Average for summer |
||
| Robe Comparison | 23.4 | 23.8 | in 1981 | 31 | 22.1 |
| Record highest summer mean daily minimum temperature | |||||
|---|---|---|---|---|---|
|
Mean daily minimum temperature for summer 2012-13 (°C) |
Previous warmest for summer |
Years of record |
Average for summer |
||
| Robe Comparison | 14.8 | = 14.8 | in 1999 | 128 | 13.3 |
Extremes Maps Records Summaries Important notes the top
| Summary statistics for summer 2012-13 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum temperatures for summer (°C) |
Minimum temperatures for summer (°C) |
Rainfall for summer (millimetres) |
||||||||||
| Mean for summer 2012-13 |
Diff from average |
Highest for summer 2012-13 |
Mean for summer 2012-13 |
Diff from average |
Lowest for summer 2012-13 |
Total for summer 2012-13 |
Average for summer |
Rank of summer 2012-13 |
Fraction of summer average |
|||
| Northwest (district 16) | ||||||||||||
| Andamooka | 36.8 | +1.3 | 47.2 | 6 Jan 2013 | 21.5 | +0.9 | 13.2 | 5 Dec 2012 | 27.1 | 61.3 | low | 44% |
| Coober Pedy Airport | 36.8 | 46.3 | 7 Jan 2013 | 21.5 | 13.4 | 1 Feb 2013 | 14.6 | |||||
| Ernabella (Pukatja) | 35.6 | 43.8 | 11 Jan 2013 | 20.9 | 13.9 | 3 Feb 2013 | 79.0 | |||||
| Roxby Downs (Olympic Dam Aerodrome) | 36.8 | 47.3 | 6 Jan 2013 | 20.0 | 12.5 | 5 Dec 2012 | 33.6 | |||||
| Tarcoola Aero | 36.5 | 47.4 | 4 Jan 2013 | 18.9 | 9.8 | 5 Dec 2012 | 17.8 | |||||
| Woomera Aerodrome | 35.1 | +1.6 | 46.1 | 4 Jan 2013 | 19.5 | +0.7 | 11.4 | 5 Dec 2012 | 23.4 | 49.3 | low | 47% |
| Far North (district 17) | ||||||||||||
| Arkaroola | 35.3 | +2.0 | 44.8 | 5 Jan 2013 | 20.4 | +1.4 | 12.6 | 2 Feb 2013 | 55.9 | 96.8 | average | 58% |
| Leigh Creek Airport | 36.6 | +2.3 | 46.3 | 6 Jan 2013 | 20.3 | +0.4 | 10.7 | 5 Dec 2012 | 58.0 | 73.0 | average | 79% |
| Marree Aero | 38.7 | 48.3 | 5 Jan 2013 | 21.7 | 12.7 | 5 Dec 2012 | 25.2 | |||||
| Marree Comparison | 39.4 | +2.5 | 48.4 | 8 Jan 2013 | 21.2 | +0.5 | 12.0 | 29 Jan 2013 | 25.8 | 54.7 | average | 47% |
| Moomba Airport | 39.8 | 49.6 | 12 Jan 2013 | 23.6 | 15.1 | 6 Dec 2012 | 14.4 | |||||
| Oodnadatta Airport | 39.4 | +2.5 | 48.2 | 8 Jan 2013 | 23.4 | +1.2 | 14.6 | 3 Feb 2013 | 3.6 | 72.0 | v low | 5% |
| Western Agricultural (district 18) | ||||||||||||
| Ceduna AMO | 29.0 | +0.9 | 46.2 | 17 Jan 2013 | 15.2 | +0.4 | 6.1 | 5 Dec 2012 | 26.8 | 45.9 | average | 58% |
| Cleve | 28.6 | +1.0 | 45.0 | 4 Jan 2013 | 16.3 | +1.1 | 9.3 | 5 Dec 2012 | 42.6 | 63.6 | average | 67% |
| Coulta (Coles Point) | 27.8 | +1.1 | 39.7 | 4 Jan 2013 | 14.6 | -0.1 | 6.2 | 21 Dec 2012 | 17.0 | |||
| Cummins Aero | 29.8 | 43.9 | 17 Jan 2013 | 13.9 | 5.2 | 2 Dec 2012 | 13.2 | |||||
| Elliston | 26.6 | +1.3 | 41.4 | 17 Jan 2013 | 15.9 | +0.5 | 9.2 | 26 Dec 2012 | 18.4 | 40.2 | low | 46% |
| Kimba | 32.3 | +1.7 | 46.0 | 4 Jan 2013 | 6.5 | 5 Dec 2012 | 46.4 | 57.7 | average | 80% | ||
| Kyancutta | 33.6 | +1.6 | 48.0 | 4 Jan 2013 | 14.4 | +0.5 | 4.1 | 5 Dec 2012 | 26.8 | 50.4 | low | 53% |
| Minnipa Pirsa | 32.6 | 46.9 | 4 Jan 2013 | 15.3 | 7.5 | 5 Dec 2012 | 32.6 | |||||
| Neptune Island | 23.1 | +1.5 | 32.7 | 17 Jan 2013 | 17.0 | +1.1 | 13.8 | 4 Dec 2012 | 15.4 | 43.3 | v low | 36% |
| North Shields (Port Lincoln AWS) | 27.0 | +1.6 | 45.6 | 17 Jan 2013 | 15.3 | 0.0 | 8.1 | 3 Dec 2012 | 14.2 | |||
| Nullarbor | 28.2 | +0.9 | 46.8 | 3 Jan 2013 | 15.7 | +0.4 | 8.1 | 5 Dec 2012 | 42.6 | 39.8 | average | 107% |
| Port Augusta Aero | 34.1 | 47.7 | 4 Jan 2013 | 18.6 | 12.0 | 30 Jan 2013 | 24.4 | |||||
| Streaky Bay | 29.9 | +1.3 | 43.3 | 17 Jan 2013 | 16.3 | +0.6 | 8.5 | 5 Dec 2012 | 23.8 | 39.2 | average | 61% |
| Whyalla Aero | 30.1 | +0.9 | 47.2 | 4 Jan 2013 | 17.8 | +0.7 | 10.1 | 6 Dec 2012 | 26.0 | 59.5 | low | 44% |
| Wudinna Aero | 33.4 | 48.2 | 4 Jan 2013 | 13.9 | 4.0 | 5 Dec 2012 | 26.0 | |||||
| Upper North (district 19) | ||||||||||||
| Hawker | 34.6 | +1.5 | 45.0 | 7 Jan 2013 | 17.8 | +0.6 | 10.0 | 5 Dec 2012 | 82.4 | 63.2 | high | 130% |
| Yongala | 31.7 | +1.9 | 42.6 | 7 Jan 2013 | 13.7 | +0.9 | 5.2 | 30 Jan 2013 | 91.4 | 68.0 | high | 134% |
| Northeast (district 20) | ||||||||||||
| Gluepot Reserve (Gluepot) | 33.3 | 45.7 | 4 Jan 2013 | 14.5 | 6.0 | 15 Jan 2013 | 42.7 | |||||
| Yunta Airstrip | 33.5 | 44.8 | 7 Jan 2013 | 15.2 | 6.9 | 15 Jan 2013 | 33.8 | |||||
| Lower North (district 21) | ||||||||||||
| Clare High School | 29.9 | 42.4 | 4 Jan 2013 | 13.9 | 6.4 | 30 Jan 2013 | 71.4 | |||||
| Port Pirie Aerodrome | 32.4 | 45.5 | 4 Jan 2013 | 16.4 | 8.5 | 5 Dec 2012 | 39.2 | |||||
| Snowtown (Rayville Park) | 31.9 | 45.4 | 4 Jan 2013 | 14.1 | 5.8 | 6 Dec 2012 | 63.8 | |||||
| Yorke Peninsula (district 22A) | ||||||||||||
| Edithburgh | 26.0 | 44.8 | 4 Jan 2013 | 16.5 | 9.6 | 30 Jan 2013 | 22.8 | 46.2 | v low | 49% | ||
| Kadina AWS | 31.2 | 46.1 | 4 Jan 2013 | 13.9 | 4.6 | 6 Dec 2012 | 25.2 | |||||
| Maitland | 29.3 | +1.2 | 44.5 | 4 Jan 2013 | 16.0 | +0.8 | 10.0 | 9 Dec 2012 | 41.0 | 62.9 | average | 65% |
| Minlaton Aero | 29.4 | 44.8 | 4 Jan 2013 | 14.5 | 6.6 | 3 Dec 2012 | 22.2 | |||||
| Stenhouse Bay | 25.6 | 41.1 | 4 Jan 2013 | 16.7 | 9.8 | 6 Dec 2012 | 21.8 | |||||
| Warooka | 27.6 | +1.0 | 41.8 | 4 Jan 2013 | 15.8 | +0.7 | 9.8 | 2 Dec 2012 | 29.2 | 49.4 | average | 59% |
| Kangaroo Island (district 22B) | ||||||||||||
| Cape Borda | 24.8 | 36.5 | 4 Jan 2013 | 14.3 | 8.7 | 6 Dec 2012 | 17.6 | |||||
| Cape Willoughby | 22.6 | +1.3 | 39.7 | 4 Jan 2013 | 16.5 | +1.0 | 11.3 | 3 Dec 2012 | 21.2 | 59.4 | v low | 36% |
| Kingscote Aero | 27.4 | 42.8 | 4 Jan 2013 | 12.3 | 4.1 | 6 Dec 2012 | 19.0 | |||||
| Parndana Cfs AWS | 26.5 | 41.6 | 17 Jan 2013 | 12.7 | 5.9 | 3 Dec 2012 | 22.0 | |||||
| Adelaide Plains (district 23A) | ||||||||||||
| Adelaide (Kent Town) | 30.0 | +1.5 | 45.0 | 4 Jan 2013 | 16.9 | +0.3 | 10.0 | 6 Dec 2012 | 35.0 | 62.2 | low | 56% |
| Adelaide Airport | 28.2 | +0.9 | 44.1 | 4 Jan 2013 | 16.2 | +0.7 | 9.1 | 6 Dec 2012 | 34.0 | 59.5 | average | 57% |
| Edinburgh RAAF | 30.1 | +0.9 | 45.2 | 4 Jan 2013 | 16.0 | +0.1 | 7.7 | 6 Dec 2012 | 34.4 | 61.5 | low | 56% |
| Parafield Airport | 30.4 | +1.6 | 44.7 | 4 Jan 2013 | 15.9 | 0.0 | 7.1 | 6 Dec 2012 | 32.2 | 63.7 | low | 51% |
| Roseworthy AWS | 31.2 | 46.0 | 4 Jan 2013 | 13.2 | 3.8 | 9 Dec 2012 | 57.2 | |||||
| County Light (district 23B) | ||||||||||||
| Nuriootpa Viticultural | 29.7 | 43.4 | 4 Jan 2013 | 13.6 | 4.3 | 1 Feb 2013 | 33.6 | |||||
| Rosedale (Turretfield Research Centre) | 31.0 | +1.3 | 45.6 | 4 Jan 2013 | 14.1 | -0.6 | 5.4 | 1 Feb 2013 | 39.1 | 60.7 | average | 64% |
| Mount Lofty Ranges (district 23C) | ||||||||||||
| Hindmarsh Island AWS | 25.9 | 43.6 | 4 Jan 2013 | 15.6 | 9.8 | 10 Dec 2012 | 30.8 | |||||
| Kuitpo Forest Reserve | 25.9 | 41.0 | 4 Jan 2013 | 13.8 | 8.0 | 10 Dec 2012 | 42.0 | |||||
| Mount Barker | 27.6 | +1.3 | 42.7 | 4 Jan 2013 | 12.6 | +1.2 | 4.2 | 6 Dec 2012 | 42.5 | 86.1 | low | 49% |
| Mount Crawford (Mt Crawford AWS) | 27.4 | 41.8 | 4 Jan 2013 | 13.5 | 6.8 | 10 Dec 2012 | 45.6 | |||||
| Mount Lofty | 24.3 | 38.5 | 4 Jan 2013 | 12.3 | 5.5 | 10 Dec 2012 | 54.2 | |||||
| Noarlunga | 28.0 | 43.4 | 4 Jan 2013 | 16.5 | 10.1 | 6 Dec 2012 | 26.8 | |||||
| Parawa (Second Valley Forest AWS) | 24.1 | 39.6 | 4 Jan 2013 | 13.7 | 7.6 | 6 Dec 2012 | 47.6 | |||||
| Victor Harbor (Encounter Bay) | 25.7 | 43.8 | 4 Jan 2013 | 13.8 | 7.3 | 21 Dec 2012 | 44.2 | |||||
| Upper Murray Valley (district 24A) | ||||||||||||
| Loxton Research Centre | 32.3 | +1.4 | 45.0 | 4 Jan 2013 | 14.4 | +0.4 | 6.9 | 6 Dec 2012 | 25.2 | 61.1 | low | 41% |
| Renmark Aero | 33.3 | 46.0 | 4 Jan 2013 | 15.3 | 7.1 | 15 Jan 2013 | 32.8 | |||||
| Lower Murray Valley (district 24B) | ||||||||||||
| Eudunda | 30.1 | +1.7 | 43.0 | 4 Jan 2013 | 14.0 | +0.5 | 6.9 | 6 Dec 2012 | 43.6 | 70.3 | average | 62% |
| Meningie | 27.1 | +1.5 | 43.0 | 4 Jan 2013 | 14.3 | +0.7 | 7.8 | 14 Jan 2013 | 26.2 | 59.0 | low | 44% |
| Murray Bridge (Pallamana Aerodrome) | 29.9 | 45.7 | 4 Jan 2013 | 13.6 | 5.3 | 6 Dec 2012 | 47.2 | |||||
| Murray Bridge Comparison | 30.2 | +1.5 | 45.6 | 4 Jan 2013 | 14.8 | +0.7 | 7.5 | 6 Dec 2012 | 47.5 | 58.4 | average | 81% |
| Strathalbyn Racecourse | 27.6 | 43.6 | 4 Jan 2013 | 14.3 | 7.6 | 6 Dec 2012 | 45.0 | |||||
| Murray Mallee (district 25A) | ||||||||||||
| Karoonda | 30.6 | 45.6 | 4 Jan 2013 | 13.5 | 7.0 | 6 Dec 2012 | 51.8 | 61.9 | average | 84% | ||
| Upper Southeast (district 25B) | ||||||||||||
| Keith | 30.0 | +0.9 | 44.8 | 4 Jan 2013 | 13.1 | +0.4 | 5.8 | 15 Jan 2013 | 41.6 | 66.2 | low | 63% |
| Keith (Munkora) | 30.7 | 46.1 | 4 Jan 2013 | 11.6 | 3.4 | 6 Dec 2012 | 58.8 | |||||
| Lameroo (Austin Plains) | 31.3 | 45.0 | 4 Jan 2013 | 12.8 | 5.0 | 1 Feb 2013 | 45.4 | |||||
| Lameroo Comparison | 31.0 | +0.9 | 44.0 | 4 Jan 2013 | 14.2 | +1.2 | 7.0 | 1 Feb 2013 | 43.4 | 66.3 | average | 65% |
| Lower Southeast (district 26) | ||||||||||||
| Cape Jaffa (The Limestone) | 25.0 | +1.1 | 38.2 | 4 Jan 2013 | 14.0 | +0.9 | 7.5 | 22 Dec 2012 | 22.8 | |||
| Coonawarra | 28.2 | +1.8 | 42.9 | 4 Jan 2013 | 11.4 | +0.3 | 2.7 | 14 Jan 2013 | 26.2 | 85.4 | lowest | 31% |
| Mount Gambier Aero | 26.6 | +2.2 | 43.6 | 4 Jan 2013 | 11.8 | +0.9 | 4.5 | 14 Jan 2013 | 47.8 | 91.8 | v low | 52% |
| Naracoorte Aerodrome | 29.2 | 44.6 | 4 Jan 2013 | 11.3 | 2.1 | 10 Dec 2012 | 20.2 | |||||
| Padthaway South | 29.0 | 43.9 | 4 Jan 2013 | 11.8 | 3.5 | 10 Dec 2012 | 48.0 | |||||
| Robe Airfield | 24.7 | 38.7 | 4 Jan 2013 | 12.9 | 4.2 | 21 Dec 2012 | 34.8 | |||||
| Robe Comparison | 23.4 | +1.3 | 34.5 | 17 Feb 2013 | 14.8 | +1.5 | 9.0 | 21 Dec 2012 | 41.0 | 66.8 | low | 61% |
Extremes Maps Records Summaries Important notes the top
A Seasonal Climate Summary is prepared to list the main features of the weather in South Australia 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 8 am on Friday 1 March 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 20 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.