Map from Google - Oslo

The climate of Oslo is Baltic semi-continental, that is, similar to that of the cities along the Baltic Sea, and it is cold in winter, with temperatures below freezing (0 °C or 32 °F), and mild or pleasantly warm in summer.
Here are the average temperatures.
Average temperatures - Oslo
Min (°C)-7-7-31711121184-2-6
Max (°C)-2-149162022201593-1
Min (°F)191927344552545246392821
Max (°F)283039486168726859483730

Precipitation amounts to 765 millimetres (30 inches) per year, and is well distributed throughout the year, however, the least rainy (or snowy) seasons are winter and spring.
Here is the average precipitation.
Average precipitation - Oslo
Prec. (mm)503545405565809090857555765
Prec. (in)

During winter the temperature stays around freezing or below from November to March. There are about 80 days with snow, occurring from late October to mid-April. However, the temperature can vary greatly: when Atlantic currents prevail, even in winter the temperature can exceed freezing, and snow can melt, while when currents blow from Siberia or a polar anticyclone moves over Scandinavia, it can drop below -20 °C (-4 °F). Due to the high latitude, the days are very short especially in December and early January (the sun sets at 3:10 pm in mid-December, and at 3:45 in mid-January), while in February the days are already a bit longer (in mid-February the sun sets at 5 p.m.), although the temperature is usually the same as in January.

In spring, in April and May, the temperatures rise quickly enough. Typically the thaw occurs in April: at the beginning of the month there may still be snow and frost, while in the month of May the first mild days occur. Spring is the season when Atlantic disturbances are, albeit slightly, less frequent. In the second half of May, in some years an anticyclone can move over northern Europe and Norway, bringing a period of nice and warm weather.

Summer, from June to August, is mild, with cool nights and pleasant days. Hot days are rare, although sometimes the temperature can reach even 30 °C (86 °F). The rains can occur even in summer, because the flow of the Atlantic fronts at these latitudes never stops: in fact there are 10/11 days with rain even in the summer months. The days are very long: roughly from mid-May to early August you can experience the phenomenon of the "white nights" in which it does not get completely dark even at midnight. However, the sun sets at a quarter to eleven in late June, at ten p.m. in late July, and at eight and three quarters in late August.

Autumn, is cool, cloudy and rainy already in September, and then gradually becomes colder. The first snowfalls can be seen already in October. In November, the days are very short, it is cold and the sun is a rarity: in fact it's already winter.

The amount of sunshine in Oslo is altogether acceptable in May and June, and even in July and August, thanks also to the length of the day. On the contrary, the sun is practically never seen from November to January, also due to the very short days.


The sea in the Oslo fjord is cold even in summer, however, it reaches 17 °C (63 °F) in July and August, which means that those who are more daring can try a dive.
Here are the average sea temperatures.
Sea temperature - Oslo
Sea (°C)544610141717151296
Sea (°F)413939435057636359544843

When to go

The best time to visit Oslo is the summer, from June to August. The temperatures are generally pleasant for outdoor activities, but at night it can be cool, or even a little cold. There's no shortage of rainy days. If you are lucky you can find daytime temperatures above 25 °C (77 °F). June is slightly cooler than August, but the days are very long, and the phenomenon of the white nights is very evident, especially around the summer solstice, the 21th of June.