The climate here is maritime, winters are mild and summers are sunny. If you look at the weather in Gdansk for 14 days at different times of the year, you will see that the seasons here are clearly defined. If it's summer, you'll find it warm and sunny, even though it often rains a lot. If it's winter, expect snow and frost - the weather in Gdansk for 5 days will predict a temperature drop to -10-15 ° C.
In summer it may be quite hot. Already from June you can expect weekly temperatures of +30-35°C in Gdansk, but in general it's still a bit cooler.
If you're heading to the city in the fall, grab an umbrella and rain gear. From late September to late November, the weather forecast for Gdansk often calls for fog and rain. That said, the very beginning of autumn is very pleasant - the air is still warm and precipitation is rare.
Whatever time of year you are planning to visit this city, check the weather in Gdansk for 3 days and take this information into account when packing your bags.