Thanks to the Gulf Stream, Scandinavia is warmer than one might expect. Oslo and most of Norway are considered to have a mild climate, but it can fluctuate greatly from year to year in the northern regions.
An interesting phenomenon in most parts of Scandinavia is the occurrence of the Midnight Sun and Polar Night. The seasons greatly determine the length of day and night. In midwinter, you can only expect about 5 to 7 hours of daylight in the Oslo region.
Daylight gets its own back in the summer, with little nighttime darkness, while summer prevails.
Except for climatic differences in the northern and southern regions, the climate also varies from coastal to inland areas. While the coast tends to more consistent with mild winters and cool summers, the inland areas have the benefit of warmer summers, but considerably colder winters. Oslo is more of the latter, but still, shares some characteristics of coastal areas.
Oslo occupies the northern end of the breathtaking Oslo Fjord. In all other directions, Oslo is surrounded by forests, ridges, and lakes. The city is considered to have a humid continental climate, according to the Koppen Climate Classification System.
Many travelers assume that Oslo is a city of eternal winter, but Oslo is as much a city of summer and sunshine as you can hope to get in this part of the world. During summer months, picnickers and fresh air enthusiasts take to the parks and countryside to make the most of the weather.
Summer weather is typically mild and pleasant, with a series of hot spells. In fact, you can expect a good deal of fine weather. July and August are the warmest months, with the average temperature a comfortable 20 degrees Celsius. Temperatures have been known to climb into the thirties, but this happens very rarely.
As the fjord is mostly encased by land, the water temperature can get quite high for this part of the world.
The weather in Norway isn't quite as tempered.
What to Expect
The days will drastically shorten in autumn as the sun plays hide and seek in Oslo. Autumn is generally a time of rapid change, and the temperature will suddenly drop to an average of 7 degrees in October. Rainfall is high during this season, and frost will gather during the night. Once the frost sets in, it is only a matter of time before snow sports enthusiasts eagerly await the arrival of winter.
In the winter, Oslo is transformed into the winter wonderland that it is known for. Snow is in abundance, making the city the place to be for winter sports. Temperatures average a chilly 0 degrees from late November right through to March, with January as the coldest month of the year and a nippy -2 degrees F. Extreme cold is rare, but temperatures of -25 F have been recorded from time to time. Ice develops on the inner parts of Oslo Fjord, and during exceptionally cold winters, the entire Fjord can freeze over. Things can be somewhat miserable in winter but with a little bit of initiative, there are plenty of winter activities for you to enjoy within the city limits.
The weather can be unpredictable because of Atlantic winds, so it is best to come prepared for all eventualities, regardless of the season.
Spring sees another rapid change in the temperature, as the winter-shy sun suddenly returns to melt the snow. Technically, spring is considered to be the driest time of the year with only light rainfall, but water is, in fact, abundant thanks to the melting snow banks. Early spring is still chilly, so don’t get too excited just yet. Keep the heavy coats close by, just in case. Rain falls moderately throughout the year at an annual precipitation (a fancy word for rainfall) of 763 millimeters. The wet season peaks in August when showers come down with more intensity.
Like most parts of the world, Oslo has seen its share of natural disasters over the past century.
Most recently, in 2010, millions of people were forced to evacuate due to floods and storms as a result of global climate changes.