Selfoss climate by month
What the weather is like
Selfoss has a subpolar oceanic climate (Köppen Cfc): rain spread through the year and no real dry season.
The warmest month is July, when afternoons average 15° and nights 9°. January is the coolest month, with highs of 3° and lows of -2°. The difference between the warmest and the coolest month is about 11°.
About 1,768 mm of precipitation falls in an average year. January is the wettest month (165 mm, 20 wet days) and December the driest (173 mm, 16 wet days). Cloud cover ranges from 48% in April to 57% in January.
The sea reaches about 12° in August. Sea temperatures lag the air by a month or two, so late summer is usually warmer for swimming than early summer.
Compared with Reykjavík, the capital, Selfoss is 0.2° warmer on a July afternoon and receives more precipitation over the year.
Year in figures
- Hottest afternoons
- 15° · July
- Coldest nights
- -2° · February
- Wettest month
- January
- Driest month
- December
- Clearest skies
- April · 48% cloud
- Warmest sea
- 12° · August
- Longest day
- 20 h 51 min
- Shortest day
- 4 h 21 min
Twelve months at a glance
Temperature and precipitation
Daily high/low range bars, monthly precipitation columns, sea temperature lineTemperature curve
Average high, low and seaDaylight
Hours between sunrise and sunset on the 15th of each monthClimate normals month by month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Average high | 3° | 4° | 5° | 8° | 11° | 14° | 15° | 15° | 12° | 8° | 5° | 4° |
| Average low | -2° | -2° | -1° | 1° | 4° | 7° | 9° | 9° | 6° | 3° | 0° | -2° |
| Precipitation | 165 mm | 156 mm | 152 mm | 126 mm | 109 mm | 105 mm | 122 mm | 152 mm | 176 mm | 174 mm | 158 mm | 173 mm |
| Wet days (≥1 mm) | 19.5 | 18.3 | 19.2 | 17.3 | 18.8 | 19.2 | 16.7 | 18.2 | 19.2 | 17.3 | 17.5 | 16.3 |
| Cloud cover | 57% | 54% | 53% | 48% | 48% | 50% | 52% | 51% | 51% | 51% | 52% | 54% |
| Sea temperature | 6° | 6° | 6° | 6° | 8° | 10° | 12° | 12° | 10° | 9° | 7° | 6° |
| Daylight | 5h 28 | 8h 38 | 11h 40 | 15h 01 | 18h 17 | 20h 51 | 19h 39 | 16h 25 | 13h 06 | 9h 54 | 6h 37 | 4h 21 |
| Month score | 14 | 15 | 15 | 18 | 24 | 36 | 44 | 41 | 26 | 16 | 16 | 15 |