Oslo is warmest in June, averaging 20° by day and 9° at night. The wettest month is July with 130 mm, and the year brings about 1088 mm in total.
Month by month
| Month | High | Low | Rain | Sea | Daylight | Good for |
|---|---|---|---|---|---|---|
| January | -3° | -9° | 84 mm | 5° | 6.4 h | Cool |
| February | -1° | -8° | 73 mm | 3° | 8.7 h | Cool |
| March | 3° | -5° | 65 mm | 3° | 11.3 h | Cool |
| April | 8° | -0° | 60 mm | 6° | 14.2 h | Cool |
| May | 15° | 5° | 65 mm | 11° | 16.8 h | Mild |
| June | 20° | 9° | 93 mm | 15° | 18.4 h | Sightseeing |
| July | 19° | 12° | 130 mm | 18° | 17.7 h | Mild |
| August | 19° | 10° | 115 mm | 18° | 15.3 h | Mild |
| September | 15° | 7° | 108 mm | 15° | 12.5 h | Mild |
| October | 9° | 2° | 112 mm | 12° | 9.7 h | Cool |
| November | 2° | -2° | 90 mm | 9° | 7.1 h | Cool |
| December | -4° | -6° | 93 mm | 6° | 5.6 h | Cool |
High and low are average daily maximum and minimum, rain is typical monthly total, sea is the average surface temperature, daylight is the hours between sunrise and sunset mid-month. Climate normals from NASA POWER and NOAA MUR — averages, not promises.
When to go
Beach weather: No month in Oslo combines swimming warmth with dry skies.
Walking the city: June — highs of 20–20° and no more than 93 mm of rain a month.