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Tallinn in September: weather, sea & travel advice
This month's data profile
Rain shapes the decision
Tallinn in September is climatically mixed. The average daily high is around 15 °C, and the sea is about 15 °C. With about 12 rainy days it is wet.
Historical monthly averages, not a weather forecast. Individual days and years can differ substantially.
Rank among 12 monthly averages
43/100 · #4
Warmth
#4
Dryness
#5
Sun
#6
Sea warmth
#3
Published best categories: City break, Active
Tallinn · SeptemberPhoto: Jorge Láscar · CC BY 2.0Climate facts
- Average high
- 15 °C
- Average low
- 11 °C
- Sea
- 15 °C
- Rainy days (est.)
- 12 rainy days (est.)
- Sun (est.)
- 3 h/day
- Humidity
- 81 %
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 | 20 | 15 | 14 | 73 | 5.3 | 77 | 4.5 | 18 | 57 |
| September (selected) | 15 | 11 | 12 | 57 | 3.3 | 81 | 5.1 | 15 | 43 |
| October | 9 | 5 | 14 | 73 | 1.4 | 87 | 5.6 | 11 | 21 |
How do the previous and next months compare?
Baseline: September (43/100)
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 | +14 | +4.6 °C | +4 °C | +2.5 | +15.7 mm | +2 h | -3.9 % | -0.6 m/s | +2.7 °C |
| October | -22 | -6.4 °C | -5.3 °C | +2.8 | +16.1 mm | -1.9 h | +5.5 % | +0.6 m/s | -4 °C |
All twelve months in context

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Useful next decisions
Frequently asked questions
How warm is Tallinn in September?
The average daily high is around 15 °C, with an average daily low of about 11 °C.
Can you swim in Tallinn in September?
The sea is about 15 °C (cold).
Does it rain a lot in Tallinn in September?
The curated estimate is about 12 rainy days per month, not a directly measured long-term average. Total precipitation averages around 57 mm for the month. A rainy day does not mean all-day rain.
When is the best time to visit Tallinn?
By the climate score, July are the strongest months for Tallinn. September is not among them.