Oslo has maritime climate. Summers are cool and winters are rather mild and snowy while autumn is long and spring comes only by late March. Severe frost or exhausting heat is not common in the city. This is peculiar considering closeness of the Polar Circle.

Weather of Oslo is mild due to influence of the Gulf Stream. The current warms up air and increases its humidity resulting mild climate.

Seasons

Contents:

• Spring
• Summer
• Autumn
• Winter

Spring in Oslo

March in Oslo is more of winter month with occasional sleet and rare rains. Temperature hovers around 2 °C (mid 30-th F). However winter frosts are gone by this time and snow have not melt yet thus March is great for skiing of all sorts.

April is warmer. Thermometer readings reach 9 °C (48 °F) and frequency of precipitation slightly decreases. It is suitable time for sightseeing and other outdoor activities. At May it becomes even warmer with daytime average about 14 °C (57 °F). Yet up to half of the month is cloudy with occasional showers.

Climate of the Spring Months

March Max average t°: +4 °C (39 °F) Min average t°: -4 °C (25 °F) Water t°: +3 °C (37 °F) Sundial in the day: 5 hours Rainy days: 6 days Precipitation: 25 mm (0.9")

April Max average t°: +10 °C (50 °F) Min average t°: +1 °C (34 °F) Water t°: +6 °C (43 °F) Sundial in the day: 6 hours Rainy days: 7 days Precipitation: 45 mm (1.8")

May Max average t°: +16 °C (61 °F) Min average t°: +6 °C (43 °F) Water t°: +11 °C (52 °F) Sundial in the day: 8 hours Rainy days: 7 days Precipitation: 45 mm (1.8")

Spring Holidays

First half of March - Holmenkollen Skifest.
Easter – Inferno Metal Festival.

May 1 – Labor Day.
May 8 – Vet’s Day/Kvinnehistorisk Natt (Women’s Day).
May 17 – Grunnlovsdag (Constitution Day in Norway).

Summer in Oslo

Middle of June marks beginning of hiking season. It is good time wander among fjords and mountains. Air warms up to 19 °C and days become longer and sunnier. And at July summer reaches its heist. Temperature of air hits 25 °C (77 °F) and the sea warms up to 18 °C (64 °F) providing suitable for swimming conditions.

At August average temperature drops to about 20 °C (68 °F) marking end of warm season. At night temperature goes lower to 10 °C (50 °F) bringing vibes of humid autumn. Toughest tourists are still swimming at the last month of summer. Other activities are still available and as pleasant as they were at beginning of the season.

Climate of the Summer Months

June Max average t°: +20 °C (68 °F) Min average t°: +10 °C (50 °F) Water t°: +14 °C (57 °F) Sundial in the day: 8 hours Rainy days: 10 days Precipitation: 70 mm (2.6")

July Max average t°: +22 °C (72 °F) Min average t°: +13 °C (55 °F) Water t°: +17 °C (63 °F) Sundial in the day: 7 hours Rainy days: 11 days Precipitation: 80 mm (3.1")

August Max average t°: +21 °C (70 °F) Min average t°: +12 °C (54 °F) Water t°: +18 °C (64 °F) Sundial in the day: 6 hours Rainy days: 11 days Precipitation: 95 mm (3.7")

Summer Holidays

June - Norwegian Wood (music festival).
June 7 -Dissolution of union with Sweden (Unionsoppløsningen).
June 23 – St. Hans's Night (Jonsok).

July 4 – Queen Sonia's Birthday.
July 12-14 – Fjord’s Day (Fjordens Dag)
July 29 - St. Olaf’s Day.

First half of August - Øya Festival (music festival).

Autumn in Oslo

September bring cooling to the capital of Norway. Temperature drops to about 15 °C (59 °F) while rains are gain intensity and days become shorter. Massive bodies of water are cooling slower than air thus transition between season is smooth. In addition autumn and winter is time of Northern Lights.

October is rainy and there is no snow yet. Temperature gradually decreases to about 9 °C (48 °F). Weather is too cold for swimming and not suitable for skiing. But other activities are completely available. At October weather is getting worse with averages of 3 °C (37 °F) and almost constant overcast and frequent rains. At night temperature often drops below 0 °C (32 °F) so you would want to have some layering.

Climate of the Autumn Months

September Max average t°: +16 °C (61 °F) Min average t°: +8 °C (46 °F) Water t°: +15 °C (59 °F) Sundial in the day: 5 hours Rainy days: 10 days Precipitation: 80 mm (3.1")

October Max average t°: +9 °C (48 °F) Min average t°: +3 °C (37 °F) Water t°: +12 °C (54 °F) Sundial in the day: 3 hours Rainy days: 10 days Precipitation: 75 mm (2.9")

November Max average t°: +3 °C (37 °F) Min average t°: -1 °C (30 °F) Water t°: +9 °C (48 °F) Sundial in the day: 4 hours Rainy days: 11 days Precipitation: 70 mm (2.8")

Autumn Holidays

First half of September – Granittrock (metal music festival).
Second half of September – Matstreif (cuisine festival), Kaffikaze Coffee festival.
September 22 – Princess Marta Louise's Birthday.

November 11 – St. Martin’s Day (Mortensdag).

Winter in Oslo

First snow falls in Oslo at October so by December winter completely takes over the city. Daytime average hovers around 0 °C (32 °F) with occasional drops to freezing -20 °C (-6 °F). Yet unlike Alaska, which is located on same longitude, there are no severe frosts in Oslo.

Norwegian winter is dull and at January there are rare frosts of -40 °C (-40 °F) with monthly average of -10 °C (14 °F). This is perfect time for skiing on 14 routs around the city. February is bit warmer with slightly longer days and as perfect for skiing as previous month was.

Climate of the Winter Months

December Max average t°: 0 °C (32 °F) Min average t°: -4 °C (25 °F) Water t°: +5 °C (41 °F) Sundial in the day: 1 hours Rainy days: 10 days Precipitation: 65 mm (2.6")

January Max average t°: -2 °C (28 °F) Min average t°: -7 °C (19 °F) Water t°: +4 °C (39 °F) Sundial in the day: 1 hours Rainy days: 8 days Precipitation: 50 mm (2.0")

February Max average t°: -1 °C (30 °F) Min average t°: -7 °C (19 °F) Water t°: +3 °C (37 °F) Sundial in the day: 3 hours Rainy days: 7 days Precipitation: 35 mm (1.4")

Winter Holidays

December 24 – Christmas Eve.
December 25 – Christmas.
December 26 – St. Stephen’s Day.

Christmas celebrations – numerous fairs.
January 1 – New Year (Nyttår).

February – Shrovetide (Fastelavn).
February 21 - Birthday of King of Norway Harald V.