September weather forecastÖsthammar, Sweden
September
Weather in September
Sea temperature
In September, the average sea temperature in Östhammar, Sweden, is 14°C (57.2°F).Note: At temperatures below 10°C (50°F), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Even a short swim, without thermal protection, at temperatures around 13°C (55.4°F) is not comfortable.
Daylight
In Östhammar, the average length of the day in September is 12h and 52min.On the first day of September, sunrise is at 05:42 and sunset at 19:50. On the last day of the month, sunrise is at 06:51 and sunset at 18:21 CEST.
Updated: Feb 2, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
In Östhammar, Sweden, the average seawater temperature in September is 14°C (57.2°F). Swimming in 14°C (57.2°F) is considered life-threatening. Even a few minutes in 13°C (55.4°F) water is uncomfortable, and swimming below 10°C (50°F) may cause total loss of breathing control and cold shock, depending on a person's physique.
In Östhammar, the average day length in September is 12h and 52min.
On the first day of September in Östhammar, sunrise is at 05:42 and sunset at 19:50. On the last day of the month, sunrise is at 06:51 and sunset at 18:21 CEST.
Average sea temperature in September
Östhammar, Sweden
- Average sea temperature in September: 14°C
The best month for swimming (with the highest average sea temperature) is August (18.2°C).
The coldest month (with the lowest average sea temperature) is February (0.1°C).
Average daylight in September
Östhammar, Sweden
- Average daylight in September: 12h and 54min
The month with the longest days is June (Average daylight: 18h and 48min).
The month with the shortest days is December (Average daylight: 6h and 0min).





