Yes

you do need a jacket based on the weather in Portland, ME, USA 1 second ago

Why? Because it's quite chilly.
49°F9°C & Windy

Wind is 16 mph25 km/h from the S, gusting to 30 mph49 km/h
April 12
11pm48°F9°C15 mph24 km/h SWindy
April 13
12am47°F9°C14 mph23 km/h SMostly Clear
1am46°F8°C13 mph21 km/h SClear
2am45°F7°C13 mph21 km/h SClear
3am44°F7°C13 mph20 km/h SClear
4am44°F7°C12 mph19 km/h SMostly Clear
5am43°F6°C12 mph19 km/h SMostly Clear
6am43°F6°C11 mph18 km/h SMostly Clear
7am44°F7°C11 mph18 km/h SMostly Clear
8am47°F8°C12 mph19 km/h SMostly Clear
9am48°F9°C12 mph19 km/h SPartly Cloudy
10am51°F10°C12 mph20 km/h SMostly Clear
DateLowHighWindDayNight
April 1242°F6°C53°F12°C14 mph22 km/h from SERainMostly Clear
April 1342°F6°C55°F13°C11 mph18 km/h from SMostly CloudyMostly Cloudy
April 1439°F4°C59°F15°C8 mph13 km/h from WPartly CloudyDrizzle
April 1541°F5°C60°F15°C6 mph10 km/h from NWPartly CloudyClear
April 1640°F4°C62°F17°C8 mph12 km/h from NWPartly CloudyPartly Cloudy
April 1738°F3°C58°F15°C6 mph9 km/h from SEPartly CloudyRain
April 1841°F5°C47°F9°C10 mph16 km/h from ERainCloudy

Yes

Low of 42°F6°C, High of 55°F13°C
Wind: 11 mph18 km/h
Precipitation: None

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