Weather in Longyearbyen in September 2025
- September is usually the wettest month of the year in Longyearbyen;
Average weather
Average temperature in Longyearbyen in September
The expected average maximum temperature in September is +2°C with a maximum of +8°C and a minimum of -8°C.
The average maximum temperature goes down 37% by the end of the month, compared with the beginning of the month, from +6°C to 0°C.
Is Longyearbyen warm or cold in September?
Longyearbyen is typically cool in September.
Maximum temperatures go down compared to the previous month from +7°C to +3°C. The minimum temperature also goes down from +4°C to -1°C.
Pack a sweater and a jacket as there will be cooler temperatures.
Take a look at how September is compared to other months in Longyearbyen:
Climate in Longyearbyen in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +7°C | +3°C | -4°C | ||||
| Min. temperature | ||||||
| -5°C | -13°C | -23°C | ||||
| Max. temperature | ||||||
| +15°C | +14°C | +8°C | ||||
| Rainfall | ||||||
| 38 mm | 33 mm | 12 mm | ||||
| Wind | ||||||
| 3 m/s | 3 m/s | 3 m/s | ||||
| Humidity | ||||||
| 84% | 87% | 85% | ||||
| Air pressure | ||||||
| 1011 HPa | 1008 HPa | 1009 HPa | ||||
| Sunny days | ||||||
| 1 | 0 | 0 | ||||
| Cloudy days | ||||||
| 17 | 15 | 17 | ||||
| Rainy days | ||||||
| 13 | 8 | 2 | ||||
| Snowy days | ||||||
| 1 | 7 | 11 | ||||
September weather is still as ok as in August. It’s getting colder in September. From +7°C in the day, the average maximum temperature lowers to +3°C. As September arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 38 mm to 33 mm. Humidity rises from 84% to 87%. The average wind speed doesn’t change much during September, staying around 3 m/s. The days becoming less sunny, going from 1 sunny days in August to 0 in September.
October brings much the same weather, it remains ok.
Wind
The average wind speed is 3 m/s getting up to 8 m/s which is a medium breeze. You can feel it, especially getting out of the water.
The average wind speed in Longyearbyen is gradually increasing during September, going from 3 m/s to 3 m/s over the course of the month.
Rain
Snow
Here’s how September is compared with other months in the amount of snow, total mm:
How was the weather last September in Longyearbyen?
Climate Change over Years
The climate in Longyearbyen in September has not changed much over the last 43 years.
The average temperature was the lowest in 1988 (-7°C) and the highest in 2016 (+1°C). The driest year was 1998 with only 51 mm of rainfall, and the wettest year was 2016 with 381 mm.
FAQ
Is September a good time to visit Longyearbyen?
Can you sunbathe in Longyearbyen in September?
Is Longyearbyen rainy in September?
Is it sunny in Longyearbyen in September?
Monthly weather in Longyearbyen
Source of the data
For this page, we’ve looked at the typical weather in Longyearbyen, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.