Climate averages 1991–2020
Gdynia weather
in September.
A mild, moderately wet month: the 4th warmest and the 9th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Gdynia: daytime highs average 17.6°C and nights cool to about 11.6°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 65 mm of rain on roughly 11 days, which makes September a moderately wet month (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 47 min on an average September day.
The nearest other city in this atlas is Gdańsk (20 km away). In September its highs average 17.8°C, about as warm as Gdynia, with 51 mm of rain.
Among the 60 cities listed in Poland, Gdynia ranks 55th of 60 for the warmest September highs and 38th of 60 for the driest September (rainfall, lowest first). The mean September high of those 60 cities is 18.3°C; Gdynia is 0.7°C cooler than that mean.
From September to October, average highs fall by 5.3°C to 12.2°C, and monthly rainfall falls from 65 mm to 63 mm.
The annual picture
September in context
Monthly precipitation
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Gdynia climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 1.8°C-2.0°C | -2.0°C | 47 | 11.9 | 7.98 h |
| February | 2.6°C-1.9°C | -1.9°C | 38 | 10.1 | 9.710 h |
| March | 6.1°C-0.2°C | -0.2°C | 44 | 10.8 | 11.812 h |
| April | 11.6°C3.5°C | 3.5°C | 42 | 9.3 | 14.014 h |
| May | 16.3°C8.2°C | 8.2°C | 62 | 11.1 | 16.016 h |
| June | 19.6°C12.1°C | 12.1°C | 73 | 12.8 | 17.217 h |
| July | 21.9°C14.8°C | 14.8°C | 92 | 13.6 | 16.717 h |
| August | 21.9°C14.9°C | 14.9°C | 81 | 12.6 | 14.915 h |
| September, selected | 17.6°C11.6°C | 11.6°C | 65 | 11.4 | 12.813 h |
| October | 12.2°C7.2°C | 7.2°C | 63 | 11.9 | 10.611 h |
| November | 6.8°C3.1°C | 3.1°C | 50 | 11.7 | 8.59 h |
| December | 3.2°C-0.3°C | -0.3°C | 52 | 11.9 | 7.47 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Gdańsk in SeptemberPoland · 20 kmHigh 17.8°C · Low 11.4°C · 51 mm rain
- Elbląg in SeptemberPoland · 70 kmHigh 17.7°C · Low 11.6°C · 58 mm rain
- Słupsk in SeptemberPoland · 97 kmHigh 17.1°C · Low 11.8°C · 78 mm rain
- Grudziądz in SeptemberPoland · 116 kmHigh 18.2°C · Low 10.9°C · 52 mm rain
- Kaliningrad in SeptemberRussia · 129 kmHigh 17.7°C · Low 11.0°C · 59 mm rain
- Olsztyn in SeptemberPoland · 152 kmHigh 17.1°C · Low 10.1°C · 59 mm rain
- Fordon in SeptemberPoland · 154 kmHigh 18.3°C · Low 11.0°C · 50 mm rain
- Koszalin in SeptemberPoland · 157 kmHigh 17.4°C · Low 11.5°C · 68 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Gdynia) is explained once on the Gdynia year overview and on the Sources, method and limits page.