Yes

you do need a jacket based on the weather in Washington (Northwest Washington), District of Columbia, United States 1 second ago

Why? Because it's quite chilly.
33°F1°C & Mostly Clear

Wind is 8 mph13 km/h from the W, gusting to 20 mph32 km/h
March 19
7am33°F1°C8 mph13 km/h WMostly Clear
8am34°F1°C8 mph13 km/h WMostly Clear
9am36°F2°C10 mph16 km/h WMostly Clear
10am38°F4°C12 mph20 km/h WPartly Cloudy
11am40°F5°C13 mph20 km/h WMostly Cloudy
12pm42°F6°C12 mph20 km/h WMostly Cloudy
1pm44°F7°C12 mph19 km/h WPartly Cloudy
2pm46°F8°C11 mph18 km/h WPartly Cloudy
3pm49°F9°C11 mph18 km/h WMostly Cloudy
4pm51°F10°C11 mph18 km/h SWMostly Cloudy
5pm52°F11°C11 mph18 km/h SWPartly Cloudy
6pm52°F11°C10 mph17 km/h SWPartly Cloudy
DateLowHighWindDayNight
March 1933°F1°C52°F11°C11 mph17 km/h from WPartly CloudyMostly Clear
March 2039°F4°C61°F16°C12 mph19 km/h from WPartly CloudyClear
March 2130°F-1°C49°F9°C9 mph15 km/h from NWClearMostly Clear
March 2231°F-1°C53°F12°C8 mph12 km/h from SEMostly CloudyRain
March 2344°F6°C57°F14°C9 mph15 km/h from NRainRain
March 2439°F4°C53°F12°C11 mph17 km/h from NPartly CloudyPartly Cloudy
March 2537°F3°C54°F12°C10 mph15 km/h from NEPartly CloudyMostly Cloudy

Yes

Low of 38°F4°C, High of 61°F16°C
Wind: 12 mph19 km/h
Precipitation: None

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