Northam is a weather station located 170 m above sea level, 1 km from Northam. Its records go back to 1907: 100 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 18.4 °C, barely higher than over 1961–1990 (18.2 °C): a difference of 0.1 °C. The warmest year of the series is 2011 (19.6 °C) and the coldest 1917 (16.9 °C). The last complete year, 2025, ranks 49 out of 100, from warmest to coldest. Over 1961–2025, the annual mean temperature changes by +0.07 °C per decade. The station ranks 211 out of 227 stations, from the fastest rise to the slowest.
Annual mean temperature since 1907
The first ten years of the series (1907–1916) average 18.0 °C; the last ten (2010–2025) average 18.8 °C, a difference of +0.8 °C. Of the ten warmest years in the series, 6 fall after 1999. The warmest is 2011 (19.6 °C). The ten-year running mean peaks at 18.7 °C (2017) and bottoms out at 17.7 °C (1931).
Annual rainfall since 1907
On average 429 mm of rain falls per year over the 116 documented years. The wettest year, 1955, received 711 mm; the driest, 1914, only 194 mm, which is 3.7 times less. The 1991–2020 normal (399 mm per year) is 25 mm (5.9 %) below the 1961–1990 one (424 mm). Over 1991–2020, July is on average the wettest month (72 mm) and December the driest (10 mm). Between 2006 and 2025, 6 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 | 25.9 °C | 26.0 °C | +0.1 °C | 13 mm | 21 mm | +8 mm |
| February | 25.7 °C | 25.6 °C | −0.1 °C | 17 mm | 17 mm | 0 mm |
| March | 23.3 °C | 23.2 °C | −0.1 °C | 18 mm | 17 mm | −1 mm |
| April | 19.0 °C | 19.4 °C | +0.4 °C | 29 mm | 20 mm | −9 mm |
| May | 15.1 °C | 15.1 °C | 0.0 °C | 49 mm | 45 mm | −4 mm |
| June | 12.5 °C | 12.4 °C | −0.1 °C | 83 mm | 60 mm | −23 mm |
| July | 11.3 °C | 11.3 °C | 0.0 °C | 77 mm | 72 mm | −5 mm |
| August | 11.8 °C | 11.8 °C | 0.0 °C | 56 mm | 58 mm | +2 mm |
| September | 13.7 °C | 13.6 °C | −0.1 °C | 36 mm | 40 mm | +4 mm |
| October | 16.5 °C | 17.2 °C | +0.7 °C | 25 mm | 23 mm | −2 mm |
| November | 20.4 °C | 20.9 °C | +0.5 °C | 13 mm | 16 mm | +3 mm |
| December | 23.8 °C | 23.9 °C | +0.1 °C | 8 mm | 10 mm | +2 mm |
The largest temperature change is in October (+0.7 °C) and the smallest in March (−0.1 °C); over the year the mean difference is +0.1 °C, and 5 months out of twelve are warmer than before. For rainfall, the largest difference is in January (+8 mm) and the smallest in June (−23 mm).
Records at Northam
- Warmest year: 19.6 °C, in 2011
- Coldest year: 16.9 °C, in 1917
- Driest year: 194 mm, in 1914
- Wettest year: 711 mm, in 1955
- Warmest month: 29.5 °C, in February 1921
- Coldest month: 9.2 °C, in July 1925
- Wettest month: 233 mm, in June 1945
- Hottest day: 48.1 °C, on 3 February 2007
- Coldest day: −3.9 °C, on 26 June 1961
- Heaviest rain in one day: 126.2 mm, on 9 March 1934
2.7 °C separate the warmest year of the series from the coldest. Between the hottest and the coldest day on record, the range reaches 52.0 °C.
Temperature trend over 1961–2025
The regression line of annual mean temperature changes by +0.07 °C per decade between 1961 and 2025, about +0.4 °C over the whole period. That is slower than the median of the 227 stations (+0.19 °C per decade), by 0.12 °C per decade: the station ranks 211 out of 227.
The last 24 months against the 1991–2020 normal
Over the last 24 months (October 2024 to September 2026), 10 months out of 19 were warmer than the 1991–2020 normal for the same month; the mean departure is +0.4 °C. The highest departure was in January 2025 (+2.4 °C); the lowest, in July 2025 (−0.6 °C). The last twelve months add up to 356 mm of rain, which is 89 % of the 1991–2020 annual normal (399 mm).
| Month | Temperature | Departure from normal | Rain | Normal rain |
|---|---|---|---|---|
| October 2024 | 18.9 °C | +1.7 °C | 22 mm | 23 mm |
| November 2024 | 21.0 °C | +0.1 °C | 29 mm | 16 mm |
| December 2024 | – | – | 2 mm | 10 mm |
| January 2025 | 28.4 °C | +2.4 °C | 4 mm | 21 mm |
| February 2025 | 25.5 °C | −0.1 °C | 1 mm | 17 mm |
| March 2025 | – | – | 27 mm | 17 mm |
| April 2025 | 20.0 °C | +0.6 °C | 48 mm | 20 mm |
| May 2025 | 15.7 °C | +0.6 °C | 15 mm | 45 mm |
| June 2025 | 12.9 °C | +0.5 °C | 24 mm | 60 mm |
| July 2025 | 10.7 °C | −0.6 °C | 66 mm | 72 mm |
| August 2025 | 11.6 °C | −0.2 °C | 119 mm | 58 mm |
| September 2025 | 13.5 °C | −0.1 °C | 26 mm | 40 mm |
| October 2025 | 16.6 °C | −0.6 °C | 44 mm | 23 mm |
| November 2025 | 20.6 °C | −0.3 °C | 2 mm | 16 mm |
| December 2025 | 24.8 °C | +0.9 °C | 12 mm | 10 mm |
| January 2026 | – | – | 1 mm | 21 mm |
| February 2026 | 25.6 °C | 0.0 °C | 18 mm | 17 mm |
| March 2026 | 23.9 °C | +0.7 °C | 64 mm | 17 mm |
| April 2026 | 18.8 °C | −0.6 °C | 24 mm | 20 mm |
| May 2026 | – | – | 17 mm | 45 mm |
| June 2026 | – | – | 74 mm | 60 mm |
| July 2026 | 10.8 °C | −0.5 °C | 13 mm | 72 mm |
| August 2026 | 12.2 °C | +0.4 °C | 60 mm | 58 mm |
| September 2026 | 15.9 °C | +2.3 °C | 27 mm | 40 mm |
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 Northam 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 Northam?
Over 1991–2020, the annual mean temperature at Northam is 18.4 °C. It was 18.2 °C over 1961–1990, a difference of +0.1 °C.
What is the warmest year ever measured at Northam?
Since records began in 1907, the warmest year at Northam is 2011, at 19.6 °C on average. The coldest is 1917 (16.9 °C).
Is the climate at Northam getting warmer?
Yes: at Northam, the annual mean temperature rises by 0.07 °C per decade between 1961 and 2025, +0.4 °C in total. 6 of the 10 warmest years in the series fall after 1999.
Towns near this station
Neighbouring stations