Svalbard
Longyearbyen in September: weather, sea & travel advice
This month's data profile
Rain shapes the decision
Longyearbyen in September is climatically mixed. The average daily high is around 0 °C, and the sea is about 4 °C. With about 16 rainy days it is very wet.
Historical monthly averages, not a weather forecast. Individual days and years can differ substantially.
Rank among 12 monthly averages
15/100 · #8
Warmth
#4
Dryness
#12
Sun
#6
Sea warmth
#3
Published best categories: none
Longyearbyen · SeptemberPhoto: Bjørn Christian Tørrissen · CC BY-SA 4.0Climate facts
- Average high
- 0 °C
- Average low
- -2 °C
- Sea
- 4 °C
- Rainy days (est.)
- 16 rainy days (est.)
- Sun (est.)
- 2 h/day
- Humidity
- 93 %
Climate evidence with direct month comparison
The highlighted row is the selected month. Precipitation total and rainy days are separate monthly averages.
| Month | Avg high °C | Avg low °C | Rainy days (est.) | Precipitation mm | Sun h/day (est.) | Humidity % | Wind m/s | Sea °C | Score |
|---|---|---|---|---|---|---|---|---|---|
| August | 4 | 2 | 16 | 64 | 4.0 | 91 | 2.7 | 5 | 19 |
| September (selected) | 0 | -2 | 16 | 72 | 1.6 | 93 | 3.0 | 4 | 15 |
| October | -5 | -9 | 15 | 65 | 0.2 | 94 | 3.4 | 2 | 14 |
How do the previous and next months compare?
Baseline: September (15/100)
Positive and negative values show the change from the selected month.
| Score Δ | Average high Δ | Average low Δ | Rainy days Δ | Rain Δ | Sun Δ | Humidity Δ | Wind Δ | Sea Δ | |
|---|---|---|---|---|---|---|---|---|---|
| August | +4 | +3.9 °C | +3.9 °C | ±0 | -7.2 mm | +2.4 h | -1.7 % | -0.3 m/s | +1.5 °C |
| October | -1 | -5.3 °C | -6.1 °C | -1.1 | -6.9 mm | -1.4 h | +1.3 % | +0.3 m/s | -1.4 °C |
All twelve months in context
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Where to stay in Longyearbyen
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Useful next decisions
Frequently asked questions
How warm is Longyearbyen in September?
The average daily high is around 0 °C, with an average daily low of about -2 °C.
Can you swim in Longyearbyen in September?
The sea is about 4 °C (cold).
Does it rain a lot in Longyearbyen in September?
The curated estimate is about 16 rainy days per month, not a directly measured long-term average. Total precipitation averages around 72 mm for the month. A rainy day does not mean all-day rain.
When is the best time to visit Longyearbyen?
No month in Longyearbyen reaches the threshold for a clear recommendation in the climate score; the month comparison above shows the differences.