Yes

you do need a jacket based on the weather in London, UK 1 second ago

Why? Because it's not very warm out.
51°F11°C & Cloudy

Wind is 9 mph15 km/h from the SW, gusting to 21 mph34 km/h
March 19
12am51°F11°C10 mph15 km/h SWCloudy
1am51°F10°C9 mph15 km/h SWCloudy
2am50°F10°C10 mph15 km/h SWCloudy
3am51°F10°C10 mph16 km/h SWCloudy
4am52°F11°C10 mph16 km/h SWCloudy
5am53°F11°C11 mph18 km/h SWCloudy
6am54°F12°C11 mph18 km/h SWCloudy
7am55°F13°C11 mph18 km/h SWCloudy
8am56°F14°C11 mph18 km/h SWCloudy
9am58°F14°C10 mph17 km/h SWCloudy
10am59°F15°C11 mph17 km/h SWCloudy
11am60°F16°C10 mph16 km/h SWCloudy
DateLowHighWindDayNight
March 1850°F10°C60°F16°C10 mph16 km/h from SWCloudyCloudy
March 1949°F10°C63°F17°C4 mph7 km/h from SWCloudyMostly Cloudy
March 2046°F8°C60°F15°C6 mph9 km/h from WCloudyCloudy
March 2142°F6°C55°F13°C9 mph15 km/h from WDrizzleMostly Clear
March 2239°F4°C50°F10°C13 mph21 km/h from WMostly CloudyMostly Cloudy
March 2340°F5°C50°F10°C10 mph15 km/h from NWMostly CloudyMostly Cloudy
March 2436°F2°C51°F10°C12 mph19 km/h from NWDrizzlePartly Cloudy

Yes

Low of 49°F10°C, High of 64°F18°C
Wind: 4 mph7 km/h
Precipitation: 21% rain

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