Walkamin Research Station: weather history since 1965

Walkamin Research Station is a weather station located 594 m above sea level, 8 km from Tolga. Its records go back to 1965: 47 years of temperature are available up to 2025, along with rainfall and a comparison with two reference normals. Over 1991–2020 the annual mean temperature there is 22.3 °C, barely higher than over 1961–1990 (22.1 °C): a difference of 0.1 °C. The warmest year of the series is 2010 (23.1 °C) and the coldest 1977 (21.6 °C). The last complete year, 2025, ranks 1 out of 47, from warmest to coldest. Over 1965–2025, the annual mean temperature changes by +0.12 °C per decade. The station ranks 196 out of 227 stations, from the fastest rise to the slowest.

Annual mean temperature since 1965

The first ten years of the series (1970–1981) average 22.1 °C; the last ten (2011–2025) average 22.6 °C, a difference of +0.5 °C. Of the ten warmest years in the series, 7 fall after 1999. The warmest is 2010 (23.1 °C). The ten-year running mean peaks at 22.7 °C (2025) and bottoms out at 22.1 °C (1983).

Annual rainfall since 1965

On average 1048 mm of rain falls per year over the 56 documented years. The wettest year, 2024, received 1919 mm; the driest, 2002, only 452 mm, which is 4.2 times less. The 1991–2020 normal (989 mm per year) is 61 mm (5.8 %) below the 1961–1990 one (1050 mm). Over 1991–2020, February is on average the wettest month (274 mm) and September the driest (8 mm). Between 2001 and 2025, 10 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.

The largest temperature change is in June (+0.4 °C) and the smallest in August (−0.3 °C); over the year the mean difference is +0.1 °C, and 9 months out of twelve are warmer than before. For rainfall, the largest difference is in February (+60 mm) and the smallest in March (−74 mm).

Records at Walkamin Research Station

• Warmest year: 23.1 °C, in 2010
• Coldest year: 21.6 °C, in 1977
• Driest year: 452 mm, in 2002
• Wettest year: 1919 mm, in 2024
• Warmest month: 26.7 °C, in January 1994
• Coldest month: 16.3 °C, in July 2007
• Wettest month: 894 mm, in February 2000
• Hottest day: 39.8 °C, on 19 November 1990
• Coldest day: 2.6 °C, on 4 July 1984
• Heaviest rain in one day: 284.8 mm, on 28 February 2000

1.5 °C separate the warmest year of the series from the coldest. Between the hottest and the coldest day on record, the range reaches 37.2 °C.

Temperature trend over 1965–2025

The regression line of annual mean temperature changes by +0.12 °C per decade between 1965 and 2025, about +0.7 °C over the whole period. That is slower than the median of the 227 stations (+0.19 °C per decade), by 0.07 °C per decade: the station ranks 196 out of 227.

The last 24 months against the 1991–2020 normal

Over the last 24 months (October 2024 to September 2026), 18 months out of 23 were warmer than the 1991–2020 normal for the same month; the mean departure is +0.5 °C. The highest departure was in July 2025 (+2.2 °C); the lowest, in September 2026 (−1.5 °C). The last twelve months add up to 1342 mm of rain, which is 136 % of the 1991–2020 annual normal (989 mm).