Sitka weather by month
Sitka runs from about 1°C in January to 15°C in August, with October the wettest month at 381 mm.
warmest month
August
15°C
coolest month
January
1°C
wettest month
October
381 mm
worst air month
May
4 µg/m³
The whole year, month by month.
| Month | Avg temp | Rain | Sun | PM2.5 |
|---|---|---|---|---|
| January | 1°C | 350 mm | 42 h | 2 |
| February | 1°C | 159 mm | 130 h | 3 |
| March | 3°C | 213 mm | 187 h | 3 |
| April | 5°C | 148 mm | 252 h | 4 |
| May | 8°C | 220 mm | 211 h | 4 |
| June | 12°C | 94 mm | 264 h | 4 |
| July | 14°C | 226 mm | 177 h | 4 |
| August | 15°C | 201 mm | 278 h | 4 |
| September | 11°C | 310 mm | 190 h | 4 |
| October | 7°C | 381 mm | 111 h | 3 |
| November | 2°C | 240 mm | 99 h | 2 |
| December | 4°C | 377 mm | 54 h | 1 |
About 1,995 hours of sun a year. Roughly 270 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.