Temperature
Cool by day, brisk at night.
58°Ftypical September high
Typical range
September climate
September in Archipelago Sea
Finland · Europe
Cool days and some sun.
Some tradeoffs
Daytime high
58°F
Lows around 53°F
Rain
Several rainy days
Sun
9 h/day
Air feel
Very dry
Sea temp
59°F
Too cold for swimming
When to visit
Month-by-month fit
Best
Precipitation
Several rainy days. About 10 wet days this month.
33%wet-day frequency
Precip amountWet-day chanceSnowfall
Sunshine
A mix of sunshine and cloud.
9.1 hSeptember sunshine
Heat & humidity by month
Very drySeptember Heat feel
Easy airWarm airHumid air
Hourly temperature pattern
In September, afternoons feel about 50° and nights feel near 48°.
FrigidFreezingVery coldColdCoolNight hours
Clear sky
Mostly cloudy skies this month.
38%September Clear sky
Clear skyCloud
Wind pattern
Breezy September days can feel brisker in open spots.
12 mphSeptember Breezy
Sea temperature
59°FSeptember sea temp
More detailIncludes daypart comfort
Typical September day
September late afternoons are around 58°F, and early evening stays near 57°F.
Avg temp Typical range
Morning55°F
Rain19%
Cloud65%
Humid airLow
Sun intensityMinimal
Midday57°F
Rain20%
Cloud64%
Humid airLow
Sun intensityModerate
Late afternoon58°F
Rain17%
Cloud63%
Humid airLow
Sun intensityLow
Early evening57°F
Rain15%
Cloud59%
Humid airLow
Sun intensityMinimal
Best windowData tableView month-by-month numbers
View month-by-month numbers
| Month | High°F | Low°F | Rainin | Wet days | Sunh | Humidity% | Sea°F |
|---|---|---|---|---|---|---|---|
| Jan | 31 | 25 | 2.0 | 11 | 2.1 | 87 | 37 |
| Feb | 29 | 22 | 1.5 | 9 | 4.2 | 87 | 35 |
| Mar | 33 | 26 | 1.2 | 7 | 7.4 | 84 | 35 |
| Apr | 41 | 34 | 1.2 | 7 | 10.6 | 80 | 38 |
| May | 51 | 43 | 1.4 | 7 | 13.4 | 77 | 44 |
| Jun | 60 | 53 | 2.0 | 9 | 13.9 | 78 | 53 |
| Jul | 66 | 60 | 2.6 | 11 | 14.3 | 79 | 62 |
| Aug | 66 | 59 | 3.0 | 13 | 12.2 | 79 | 64 |
| Sep | 58 | 53 | 2.4 | 10 | 9.1 | 80 | 59 |
| Oct | 49 | 44 | 3.0 | 13 | 5.4 | 82 | 51 |
| Nov | 41 | 37 | 2.7 | 14 | 2.4 | 85 | 45 |
| Dec | 36 | 31 | 2.5 | 14 | 1.6 | 85 | 41 |
Similar climates
Similar
Similar travel styleBrightonUnited KingdomSimilar travel styleAnticosti IslandCanadaSimilar travel styleBar HarborUnited StatesSimilar travel styleAngleseyUnited Kingdom
Want a side-by-side climate view? Compare Archipelago Sea with Brighton.
Climate data notePlanning guidance, not a forecast
Typical monthly values are based on long-term climate records. Useful for planning, not a forecast. Check the weather before you travel.
Sunshine: source type is not yet identified at metric level.
Local microclimates can vary by beach, neighborhood, trail, or elevation.
Last updated: Jul 31, 2026
Data & methodology