September weather forecastGdynia, Poland
September
Weather in September
Entering autumn, September witnesses a marked shift in Gdynia's weather. Significant drops in temperature are evident, with highs averaging 18.4°C (65.1°F). However, the sea still invites with its 17.3°C (63.1°F) mean temperature, permitting extended seaside excursions. The town begins to shed its summer vibrancy, adopting a more tranquil, contemplative mood in the face of advancing autumn. Gdynia, in September, is a picturesque blend of summer reminiscences and mellow autumn hues.Temperature
The arrival of September is marked by a minor reduction in average high-temperature, sliding from a pleasant 22.5°C (72.5°F) in August to an enjoyable 18.4°C (65.1°F). During the month of September, Gdynia's nighttime temperature lowers to an average of 11.8°C (53.2°F).Humidity
In September, the average relative humidity in Gdynia is 82%.Rainfall
In Gdynia, in September, it is raining for 14 days, with typically 71mm (2.8") of accumulated precipitation. Throughout the year, in Gdynia, there are 183 rainfall days, and 697mm (27.44") of precipitation is accumulated.Snowfall
May through September are months without snowfall in Gdynia, Poland.Sea temperature
In September, the average sea temperature is 17.3°C (63.1°F).Note: The majority find it unenjoyable to swim in 17.3°C (63.1°F). Breathing becomes tougher as the water temperature descends under 21°C (69.8°F).
Daylight
The average length of the day in September is 12h and 43min.On the first day of September in Gdynia, sunrise is at 05:54 and sunset at 19:37. On the last day of the month, sunrise is at 06:47 and sunset at 18:24 CEST.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Gdynia, Poland
- Average high temperature in September: 18.4°C
The warmest month (with the highest average high temperature) is July (22.7°C).
The month with the lowest average high temperature is January (2°C).
- Average low temperature in September: 11.8°C
The month with the highest average low temperature is July (14.8°C).
The coldest month (with the lowest average low temperature) is January (-3.2°C).
Average humidity in September
Gdynia, Poland
- Average humidity in September: 82%
The month with the highest relative humidity is December (87%).
The month with the lowest relative humidity is May (63%).
Average rainfall in September
Gdynia, Poland
- Average rainfall in September: 71.2mm
The wettest month (with the highest rainfall) is August (74.9mm).
The driest month (with the least rainfall) is April (36.6mm).
Average rainfall days in September
Gdynia, Poland
- Average rainfall days in September: 14 days
The month with the highest number of rainy days is November (19 days).
The month with the least rainy days is February (11 days).
Average snowfall days in September
Gdynia, Poland
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (13 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average sea temperature in September
Gdynia, Poland
- Average sea temperature in September: 17.3°C
The best month for swimming (with the highest average sea temperature) is August (19.1°C).
The coldest month (with the lowest average sea temperature) is March (2.2°C).
Average daylight in September
Gdynia, Poland
- Average daylight in September: 12h and 42min
The month with the longest days is June (Average daylight: 17h and 12min).
The month with the shortest days is December (Average daylight: 7h and 24min).





