WEATHER · CLIMATE NORMALS · 1991–2020
Wellington Climate — Averages by Month
What the weather in Wellington, NZaverages across a standard 30-year period. Each month's figure is the 1991–2020 mean temperature and total rainfall from the ERA5 reanalysis — the long-run normal a place settles around, not a forecast for any particular day.
Month-by-month normals
| Month | Avg temperature | Avg rainfall |
|---|---|---|
| January | 16.0 °C | 58.9 mm |
| February | 16.4 °C · warmest | 59.5 mm |
| March | 15.5 °C | 63.9 mm |
| April | 14.0 °C | 78.2 mm |
| May | 12.6 °C | 81.2 mm |
| June | 10.9 °C | 101.6 mm · wettest |
| July | 10.1 °C · coldest | 92.4 mm |
| August | 10.2 °C | 88.3 mm |
| September | 11.0 °C | 79.3 mm |
| October | 11.9 °C | 88.2 mm |
| November | 13.0 °C | 74.1 mm |
| December | 14.7 °C | 70.1 mm |
How to read these numbers
These are reanalysis normals, not readings from a single weather station. They come from the ERA5 0.25° (~25 km) global reanalysis grid, sampled at the grid cell nearest Wellington — centred at 41.25°S, 174.75°E. A reanalysis blends observations with a physics model onto an even grid, so a coastal or mountain city's cell can read a little cooler, warmer, wetter or drier than the city centre itself. The month-to-month shape — when it's hot, when it rains — is what these normals capture best.
“Normal” means the 1991–2020 average, the current World Meteorological Organization standard period. A normal is what a place tends toward over decades — any single day, month or year can and will depart from it.