Yes

you do need a jacket based on the weather in Włocławek, Poland 1 second ago

Why? Because some drizzle out there and it's cool. Pleasantly cool, but cool!
56°F13°C & Drizzle

Wind is 9 mph15 km/h from the South, gusting to 17 mph27 km/h
July 11
11pm56°F13°C10 mph15 km/h SouthDrizzle
July 12
12am56°F14°C10 mph16 km/h SouthDrizzle
1am57°F14°C10 mph16 km/h SouthDrizzle
2am58°F14°C10 mph16 km/h SouthDrizzle
3am58°F15°C10 mph16 km/h SouthCloudy
4am59°F15°C11 mph17 km/h SouthCloudy
5am60°F16°C11 mph17 km/h SouthCloudy
6am61°F16°C10 mph17 km/h SouthCloudy
7am62°F17°C11 mph17 km/h SouthCloudy
8am63°F17°C11 mph18 km/h SouthCloudy
9am64°F18°C10 mph16 km/h SouthCloudy
10am65°F18°C9 mph15 km/h SouthCloudy
DateLowHighWindDayNight
July 1156°F13°C66°F19°C10 mph16 km/h from SouthDrizzleDrizzle
July 1258°F15°C73°F23°C9 mph14 km/h from SoutheastRainDrizzle
July 1359°F15°C75°F24°C5 mph8 km/h from SouthwestDrizzleMostly Clear
July 1460°F15°C76°F25°C7 mph12 km/h from WestPartly CloudyDrizzle
July 1559°F15°C72°F22°C10 mph16 km/h from WestDrizzleRain
July 1658°F14°C70°F21°C8 mph13 km/h from WestDrizzlePartly Cloudy
July 1759°F15°C75°F24°C9 mph15 km/h from WestDrizzlePartly Cloudy

Yes

Low of 58°F15°C, High of 73°F23°C
Wind: 9 mph14 km/h
Precipitation: 60% rain

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