Casterton Showgrounds is a weather station located 71 m above sea level, 1 km from Casterton. Its records go back to 1957: 47 years of temperature are available up to 2017, along with rainfall and a comparison with two reference normals. Closed series: the records of this station end in 2017. Over the whole series (47 years) the annual mean temperature there is 14.1 °C; the 1961–1990 and 1991–2020 reference periods are not documented well enough for a comparison. The warmest year of the series is 2007 (15.6 °C) and the coldest 1964 (13.4 °C). The last complete year, 2009, ranks 5 out of 47, from warmest to coldest. Over 1961–2017, the annual mean temperature changes by +0.05 °C per decade. The station ranks 215 out of 227 stations, from the fastest rise to the slowest.
Annual mean temperature since 1957
The first ten years of the series (1957–1966) average 13.9 °C; the last ten (1994–2009) average 14.2 °C, a difference of +0.3 °C. Of the ten warmest years in the series, 2 fall after 1999. The warmest is 2007 (15.6 °C). The ten-year running mean peaks at 14.3 °C (1982) and bottoms out at 13.9 °C (1966).
Annual rainfall since 1957
On average 646 mm of rain falls per year over the 58 documented years. The wettest year, 1971, received 899 mm; the driest, 1982, only 370 mm, which is 2.4 times less. The 1991–2020 normal (638 mm per year) is 18 mm (2.7 %) below the 1961–1990 one (656 mm). Over 1991–2020, August is on average the wettest month (83 mm) and February the driest (21 mm). Between 1995 and 2017, 11 years out of 20 exceeded the series average.
Monthly normals: 1961–1990 against 1991–2020
The table compares, month by month, the mean temperature and the rainfall total of two thirty-year reference periods. The difference column shows what the recent period changes compared with the earlier one.
| Month | Temp. 1961–1990 | Temp. 1991–2020 | Difference | Rain 1961–1990 | Rain 1991–2020 | Difference |
|---|---|---|---|---|---|---|
| January | 19.3 °C | – | – | 25 mm | 38 mm | +13 mm |
| February | 19.6 °C | – | – | 21 mm | 21 mm | 0 mm |
| March | 17.8 °C | – | – | 35 mm | 34 mm | −1 mm |
| April | 14.9 °C | – | – | 44 mm | 44 mm | 0 mm |
| May | 12.0 °C | – | – | 64 mm | 58 mm | −6 mm |
| June | 9.8 °C | – | – | 67 mm | 74 mm | +7 mm |
| July | 9.2 °C | – | – | 92 mm | 82 mm | −10 mm |
| August | 10.0 °C | 10.1 °C | +0.1 °C | 85 mm | 83 mm | −2 mm |
| September | 11.5 °C | – | – | 71 mm | 74 mm | +3 mm |
| October | 13.1 °C | 13.1 °C | 0.0 °C | 62 mm | 53 mm | −9 mm |
| November | 15.2 °C | – | – | 49 mm | 42 mm | −7 mm |
| December | 17.3 °C | – | – | 41 mm | 35 mm | −6 mm |
For rainfall, the largest difference is in January (+13 mm) and the smallest in July (−10 mm).
Records at Casterton Showgrounds
- Warmest year: 15.6 °C, in 2007
- Coldest year: 13.4 °C, in 1964
- Driest year: 370 mm, in 1982
- Wettest year: 899 mm, in 1971
- Warmest month: 22.7 °C, in January 1961
- Coldest month: 7.6 °C, in July 1982
- Wettest month: 187 mm, in July 1964
- Hottest day: 44.3 °C, on 19 January 1959
- Coldest day: −4.6 °C, on 19 July 1965
- Heaviest rain in one day: 114.0 mm, on 20 January 2007
2.2 °C separate the warmest year of the series from the coldest. Between the hottest and the coldest day on record, the range reaches 48.9 °C.
Temperature trend over 1961–2017
The regression line of annual mean temperature changes by +0.05 °C per decade between 1961 and 2017, about +0.3 °C over the whole period. That is slower than the median of the 227 stations (+0.19 °C per decade), by 0.14 °C per decade: the station ranks 215 out of 227.
Data source and licence
Data source: Bureau of Meteorology (ACORN-SAT) and NOAA NCEI (GHCN-Daily) (dataset “ACORN-SAT v2 daily (homogenised) + GHCN-Daily”), licence CC BY 4.0; Public domain (NOAA NCEI). Last updated: 29 October 2026.
The data for Casterton Showgrounds are shown as the source publishes them; this site does not correct them. A year is kept only if at least eleven months of measurements are available, and a normal is computed only with at least twenty years of data out of its thirty. Temperatures are rounded to 0.1 °C and rainfall to the millimetre. The station is one of 227 stations in Australia: the overview page lets you compare them.
Frequently asked questions
What is the annual mean temperature at Casterton Showgrounds?
Over the whole series (47 years), the annual mean temperature at Casterton Showgrounds is 14.1 °C.
What is the warmest year ever measured at Casterton Showgrounds?
Since records began in 1957, the warmest year at Casterton Showgrounds is 2007, at 15.6 °C on average. The coldest is 1964 (13.4 °C).
Is the climate at Casterton Showgrounds getting warmer?
The rise is not clear at Casterton Showgrounds: the trend is +0.05 °C per decade between 1961 and 2017, +0.3 °C in total over the period.
Towns near this station
Neighbouring stations