2015 was Australia's fifth-warmest year on record, while
national rainfall was slightly below average according to data collected
and analysed by the Bureau of Meteorology.
Summary
2015 was Australia's fifth-warmest year on record (national observations
commence in 1910). Above average temperatures were persistent
throughout the year, with several periods of record warmth.
Summary
- 2015 was another warm year, especially during the last three months
- Strong El Niño, comparable to the El Niño events of 1997–98 and 1982–83
- Overall, it was Australia's fifth-warmest year on record with the annual national mean temperature 0.83 °C above average
- Warmest October on record nationally, for both maxima and minima, with the largest mean temperature anomaly on record for any month
- Western Australia, Queensland, Victoria, South Australia, and New South Wales ranked in the ten warmest years on record
- Nationally-averaged rainfall 5% below average for the year, at 443.7 mm (1961–1990 average 465.2 mm)
- Rainfall below average for parts of the Top End, most of Queensland, Victoria, Tasmania, southeast and western South Australia, and southwest Western Australia
- Rainfall above average for the Gascoyne and Pilbara in Western Australia, most of the central Northern Territory, northeastern South Australia, and northwestern New South Wales
The Australian area-averaged mean temperature for 2015 was 0.83 °C above the 1961–1990 average. Maximum temperatures were 0.96 °C above average, and minimum temperatures were 0.69 °C above average; both the sixth-warmest on record respectively.
Looking at recent years more broadly, eight of Australia's ten warmest years on record have occurred since 2002. The 10-year mean temperature for 2006–2015 was the second highest on record at 0.53 °C above average (and just behind 2005–2014). Only one year in the past ten was cooler than average: 2011.
Annual mean temperatures for 2015 were above to very much above average for the majority of Australia, although much of the central Northern Territory and northwest of the Kimberley in Western Australia observed a near-average annual mean temperature.
After a near miss in 2014, El Niño became established during May and strengthened to become one of the strongest on record (alongside 1972–73, 1982–83 and 1997–98). The combination of El Niño and background warming led to very warm temperatures globally throughout 2015, and contributed to Australia's warm year.
El Niño also led to below average rainfall over much of eastern Australia, although record-warm sea surface temperatures (SSTs) in the Indian Ocean initially moderated the effect of the El Niño. Between late August and mid-November a positive Indian Ocean Dipole (IOD) had the opposite effect, reinforcing drying over much of Australia as the flow of moisture from the Indian Ocean was reduced.
The Australian mean rainfall for 2015 was 5% below the 1961–1990 climatological average of 465.2 mm. 2015 was Australia's 57th-driest year on record, with an area-average total of 443.7 mm—close to the median.
Annual rainfall was below average across most of Queensland and parts of the Northern Territory's Top End; Victoria and southeast South Australia; Tasmania; the western half of South Australia and the far southwest of the Northern Territory; and the southwest of Western Australia. Rainfall was above average for the Gascoyne and Pilbara in Western Australia; areas of the Northern Territory stretching from the western Top End, across the central region, through the southeast of the Northern Territory and across northeastern South Australia, into northwestern New South Wales; and also for small parts of the east coast between southeastern Queensland and East Gippsland in Victoria.
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| 2015 annual mean temperatures compared to historical temperature observations. See also maxima and minima. |
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| 2015 annual rainfall compared to historical rainfall observations. See definition of deciles. |
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