Honolulu weather by month
Honolulu runs from about 22°C in February to 26°C in September, with May the wettest month at 165 mm.
warmest month
September
26°C
coolest month
February
22°C
wettest month
May
165 mm
worst air month
May
8 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 22°C | 141 mm | 301 h | 7 |
| February | 22°C | 21 mm | 299 h | 7 |
| March | 22°C | 22 mm | 324 h | 6 |
| April | 23°C | 72 mm | 341 h | 7 |
| May | 24°C | 165 mm | 372 h | 8 |
| June | 25°C | 13 mm | 388 h | 8 |
| July | 25°C | 16 mm | 397 h | 6 |
| August | 26°C | 48 mm | 370 h | 6 |
| September | 26°C | 13 mm | 349 h | 5 |
| October | 25°C | 28 mm | 332 h | 5 |
| November | 24°C | 21 mm | 318 h | 6 |
| December | 23°C | 18 mm | 325 h | 6 |
About 4,116 hours of sun a year. Roughly 58 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 2026-05-23. Full method, licences and the list of sources we rejected are on the methodology page.