Yes

you do need a jacket based on the weather in Oulu, Finland 1 second ago

Why? Because it's cool. Pleasantly cool, but cool!
58°F15°C & Clear

Wind is 5 mph8 km/h from the Southwest, gusting to 11 mph18 km/h
August 11
5pm58°F15°C5 mph8 km/h SouthwestClear
6pm57°F14°C5 mph8 km/h SouthwestClear
7pm57°F14°C5 mph7 km/h SouthwestMostly Clear
8pm56°F13°C4 mph7 km/h SouthwestMostly Clear
9pm55°F13°C4 mph7 km/h SouthwestMostly Clear
10pm55°F13°C4 mph6 km/h SouthwestMostly Clear
11pm55°F13°C4 mph7 km/h SouthwestMostly Clear
August 12
12am58°F14°C5 mph9 km/h SouthwestClear
1am60°F16°C6 mph10 km/h SouthwestMostly Clear
2am63°F17°C7 mph12 km/h WestMostly Clear
3am64°F18°C8 mph13 km/h WestPartly Cloudy
4am65°F19°C9 mph14 km/h WestMostly Clear
DateLowHighWindDayNight
August 1056°F13°C66°F19°C9 mph14 km/h from WestMostly ClearClear
August 1155°F13°C67°F20°C9 mph14 km/h from WestMostly ClearMostly Clear
August 1253°F12°C67°F20°C7 mph11 km/h from WestMostly ClearMostly Clear
August 1353°F12°C71°F22°C7 mph11 km/h from SouthwestMostly CloudyPartly Cloudy
August 1460°F15°C71°F22°C8 mph14 km/h from SouthwestRainRain
August 1557°F14°C63°F17°C11 mph18 km/h from WestDrizzleMostly Cloudy
August 1655°F13°C66°F19°C11 mph17 km/h from NorthwestPartly CloudyMostly Clear

Yes

Low of 55°F13°C, High of 67°F20°C
Wind: 9 mph14 km/h
Precipitation: None

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