Gdynia weather in September
Temperature, sea and sunshine in September: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in September
Good
Best time to visit: May – September
What is the weather like in Gdynia in September?
In September, Gdynia is mild: daytime highs average 18 °C, and nights cool down to about 12 °C. The sea averages 16.8 °C – swimming is only for the hardy. Expect around 5 hours of sunshine a day. Rain is frequent, with about 11 rainy days and 60 mm in total. All in all, September is a good month for a holiday in Gdynia.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 75 | 70 | 33 |
| Day | 21° | 18° | 12° |
| Night | 15° | 12° | 8° |
| Sea | 19° | 17° | 13° |
| Sun | 7 h | 5 h | 3 h |
| Rain days | 13 | 11 | 13 |
More details for September
- Daylight
- 12 h 49 min06:17 – 19:06
- UV index
- 3 · moderateclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 23 km/haverage daily peakAll months
- Cloud cover
- 61 %on averageAll months
- Hot days
- 0 days30 °C or more
- Snow days
- 0 days1 cm or more of fresh snowAll months
- Time zone
- UTC+2Europe/Warsaw
How the score comes together
- Temperatureweight 50 %96 %
- Sunshineweight 20 %38 %
- Few rainy daysweight 30 %49 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in September
- Sunscreen
- A jumper for the evenings
- Rain jacket or umbrella
Gdynia in September: quick answers
Is Gdynia hot in September?
No. In September, Gdynia is mild: daytime highs average 18 °C and nights drop to about 12 °C.
Can you swim in Gdynia in September?
Only if you don't mind cold water: in September the sea averages just 16.8 °C. Comfortable swimming temperatures are not reached at any time of year.
Does it rain much in Gdynia in September?
Rain is frequent, with about 11 rainy days and 60 mm in total.
Gdynia month by month
The whole year in GdyniaAll destinations: PolandWhere to go in SeptemberSea temperature in September
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences