Yes

you do need a jacket based on the weather in Sitka, AK, USA 1 second ago

Why? Because it's drizzling and a jacket will keep you cozy, but you won't break a seat!
54°F12°C & Drizzle

Wind is 10 mph16 km/h from the Southeast, gusting to 17 mph28 km/h
September 10
9am54°F12°C11 mph17 km/h SoutheastRain
10am54°F12°C11 mph18 km/h SoutheastRain
11am54°F12°C11 mph18 km/h SoutheastRain
12pm55°F13°C12 mph19 km/h SoutheastRain
1pm55°F13°C12 mph19 km/h SoutheastRain
2pm56°F13°C13 mph20 km/h SoutheastRain
3pm56°F13°C12 mph20 km/h SoutheastRain
4pm57°F14°C12 mph19 km/h SoutheastRain
5pm57°F14°C12 mph20 km/h SoutheastRain
6pm57°F14°C12 mph19 km/h SoutheastRain
7pm57°F14°C11 mph18 km/h SoutheastRain
8pm57°F14°C11 mph18 km/h SoutheastRain
DateLowHighWindDayNight
September 1054°F12°C57°F14°C12 mph19 km/h from SoutheastRainRain
September 1152°F11°C57°F14°C9 mph14 km/h from SouthDrizzleDrizzle
September 1250°F10°C57°F14°C7 mph11 km/h from SouthDrizzleMostly Clear
September 1348°F9°C56°F14°C3 mph5 km/h from WestPartly CloudyDrizzle
September 1447°F9°C56°F13°C3 mph5 km/h from SouthwestDrizzleDrizzle
September 1550°F10°C56°F13°C8 mph13 km/h from SoutheastRainRain
September 1649°F9°C55°F13°C4 mph7 km/h from SouthRainDrizzle

Yes

Low of 52°F11°C, High of 56°F14°C
Wind: 9 mph14 km/h
Precipitation: 75% rain

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