New Plymouth weather by month
New Plymouth runs from about 10°C in July to 19°C in January, with August the wettest month at 249 mm.
warmest month
January
19°C
coolest month
July
10°C
wettest month
August
249 mm
worst air month
October
7 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 19°C | 111 mm | 356 h | 6 |
| February | 18°C | 72 mm | 339 h | 6 |
| March | 16°C | 87 mm | 301 h | 5 |
| April | 15°C | 171 mm | 263 h | 4 |
| May | 12°C | 84 mm | 248 h | 4 |
| June | 12°C | 117 mm | 205 h | 4 |
| July | 10°C | 194 mm | 208 h | 3 |
| August | 11°C | 249 mm | 228 h | 4 |
| September | 12°C | 151 mm | 279 h | 6 |
| October | 14°C | 145 mm | 309 h | 7 |
| November | 15°C | 90 mm | 304 h | 7 |
| December | 17°C | 95 mm | 343 h | 6 |
About 3,383 hours of sun a year. Roughly 157 rainy days a year.
These are long-run climate normals, not a forecast. A given year can sit well outside them. PM2.5 is a global model: near the coast it counts sea salt as fine particulate and reads high against ground stations, sometimes by a factor of two. Use the shape of the year, not the absolute number.
where these numbers come from
- · Temperature, rainfall and sunshine: ECMWF ERA5 reanalysis climate normals via Open-Meteo (CC BY 4.0), fetched once and stored.
- · PM2.5: Copernicus CAMS reanalysis, monthly means. Modelled, not station readings; near coasts CAMS counts sea salt as PM2.5 and reads high.
Last reviewed 2026-05-27. Full method, licences and the list of sources we rejected are on the methodology page.