Climate Insights for Porsgrunn

The climate in Porsgrunn is cool. The average annual temperature is 7°C and approximately 1138mm of precipitation falls per year. Porsgrunn receives a notable amount of rainfall throughout the year, including during its driest month. Porsgrunn is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, June, August. The coldest months are January, February, December, when temperatures can drop to -5°C. Porsgrunn experiences heavy snowfall, typically from January through December.

Temperatures in Porsgrunn vary considerably across the year, with a 26°C difference between the coldest and warmest months. July is the warmest month, though highs remain moderate at 21°C with a mean of 17°C. The coldest month is January, when overnight lows fall to -5°C and the daily average is -2°C. Daily temperature variation is modest, with an average difference of 7°C between highs and lows. The sharpest temperature change occurs between April and May, with a 6°C shift in average temperatures.

Porsgrunn is a moderately rainy area, receiving approximately 1138mm of precipitation annually, which averages out to around 95mm per month. The wettest month is September, averaging 125mm of rainfall. October and November also tend to see above-average precipitation. The driest month is April, with just 54mm. That's 71mm less than September, the wettest month. Rainfall is relatively evenly distributed throughout the year, so there is no pronounced dry or wet season to plan around. Porsgrunn receives heavy snowfall, accumulating around 254cm annually from January through December. The snowiest month is January, with approximately 69cm. Winter travel should account for significant snow cover.

Porsgrunn is relatively calm, with an average annual wind speed of 10km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is January, averaging 12km/h, though still comfortable for most outdoor activities. The calmest conditions occur in July, with average winds dropping to 9km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 3km/h between the calmest and windiest months. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 11km/h in winter, 10km/h in spring, 9km/h in summer, 11km/h in autumn.

It is currently autumn in Porsgrunn, which began on September 23, 2026. Porsgrunn is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in July at around 21°C, while the coldest stretch bottoms out in January near -5°C. Winter is next, beginning on December 21, 2026 (87 days from now).

The best time to visit Porsgrunn is during June, when the weather is most comfortable for travellers. During these months, average temperatures hover around 15°C with modest rainfall averaging 91mm per month. By contrast, July can be uncomfortably hot with highs reaching 21°C, while January is the coldest period with lows dropping to -5°C. Despite being the best months overall, some rain is still likely. Pack a waterproof layer and plan a mix of indoor and outdoor activities.

The table below shows monthly climate averages for Porsgrunn based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.