Yes

you do need a jacket based on the weather in London SW1P 4RG, UK 1 second ago

Why? Because it's so windy, you’re practically horizontal just trying to walk!
74°F23°C & Cloudy

Wind is 12 mph20 km/h from the Southwest, gusting to 29 mph46 km/h
September 7
1pm73°F23°C12 mph19 km/h SouthwestCloudy
2pm71°F22°C11 mph17 km/h SouthwestMostly Cloudy
3pm69°F21°C10 mph16 km/h SouthwestPartly Cloudy
4pm67°F19°C9 mph15 km/h SouthwestMostly Clear
5pm65°F18°C9 mph14 km/h SouthwestPartly Cloudy
6pm63°F17°C8 mph12 km/h SouthwestMostly Cloudy
7pm62°F17°C7 mph12 km/h SouthwestMostly Cloudy
8pm61°F16°C7 mph11 km/h SouthwestPartly Cloudy
9pm60°F16°C6 mph10 km/h SouthwestMostly Clear
10pm59°F15°C5 mph9 km/h SouthwestMostly Clear
11pm58°F15°C5 mph9 km/h SouthwestMostly Clear
September 8
12am58°F14°C5 mph9 km/h SouthwestMostly Clear
DateLowHighWindDayNight
September 660°F16°C78°F25°C9 mph14 km/h from SouthMostly CloudyPartly Cloudy
September 757°F14°C69°F21°C7 mph12 km/h from SouthwestMostly ClearMostly Clear
September 853°F12°C69°F21°C5 mph8 km/h from SouthPartly CloudyPartly Cloudy
September 955°F13°C67°F20°C10 mph16 km/h from SouthMostly CloudyRain
September 1053°F12°C64°F18°C11 mph18 km/h from SouthwestDrizzleMostly Clear
September 1150°F10°C64°F18°C10 mph17 km/h from SouthwestDrizzleDrizzle
September 1250°F10°C63°F17°C10 mph16 km/h from SouthwestDrizzleRain

Yes

Low of 56°F14°C, High of 69°F21°C
Wind: 7 mph12 km/h
Precipitation: None

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