Yes

you do need a jacket based on the weather in Seattle, WA 98103, USA 1 second ago

Why? Because just cool enough for a jacket, but not warm enough to ditch it!
53°F11°C & Cloudy

Wind is 4 mph7 km/h from the Northeast, gusting to 11 mph17 km/h
April 29
11pm52°F11°C5 mph8 km/h NortheastMostly Cloudy
April 30
12am50°F10°C4 mph7 km/h EastPartly Cloudy
1am49°F9°C4 mph6 km/h EastCloudy
2am49°F9°C4 mph6 km/h SoutheastCloudy
3am48°F9°C3 mph5 km/h SoutheastMostly Cloudy
4am47°F8°C3 mph5 km/h SoutheastPartly Cloudy
5am46°F8°C4 mph6 km/h SoutheastPartly Cloudy
6am45°F7°C3 mph5 km/h SoutheastPartly Cloudy
7am45°F7°C2 mph4 km/h SoutheastPartly Cloudy
8am44°F7°C2 mph4 km/h SouthPartly Cloudy
9am44°F7°C2 mph3 km/h SouthPartly Cloudy
10am45°F7°C2 mph3 km/h SouthwestPartly Cloudy
DateLowHighWindDayNight
April 2948°F9°C54°F12°C2 mph3 km/h from NorthCloudyMostly Cloudy
April 3044°F7°C63°F17°C4 mph6 km/h from NorthPartly CloudyClear
May 145°F7°C71°F22°C5 mph8 km/h from NorthClearClear
May 250°F10°C67°F20°C9 mph15 km/h from SouthwestMostly ClearRain
May 347°F9°C56°F13°C5 mph8 km/h from NorthMostly CloudyMostly Clear
May 445°F7°C61°F16°C6 mph10 km/h from NorthMostly ClearMostly Clear
May 545°F7°C67°F20°C5 mph7 km/h from NorthMostly ClearPartly Cloudy

Yes

Low of 44°F7°C, High of 63°F17°C
Wind: 4 mph6 km/h
Precipitation: None

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