Yes

you do need a jacket based on the weather in Westminster, London SW1, UK 1 second ago

Why? Because it's cool. Pleasantly cool, but cool!
52°F11°C & Mostly Cloudy

Wind is 7 mph12 km/h from the Southwest, gusting to 19 mph30 km/h
November 1
7pm52°F11°C8 mph13 km/h SouthwestMostly Cloudy
8pm51°F11°C7 mph12 km/h SouthwestCloudy
9pm51°F11°C8 mph12 km/h SouthwestMostly Cloudy
10pm50°F10°C8 mph12 km/h SouthwestPartly Cloudy
11pm49°F10°C7 mph11 km/h SouthwestPartly Cloudy
November 2
12am48°F9°C6 mph10 km/h SouthwestMostly Clear
1am48°F9°C6 mph10 km/h SouthwestMostly Clear
2am47°F8°C6 mph10 km/h SouthwestPartly Cloudy
3am47°F8°C6 mph9 km/h SouthPartly Cloudy
4am47°F8°C6 mph10 km/h SouthMostly Cloudy
5am47°F8°C7 mph11 km/h SouthMostly Cloudy
6am48°F9°C9 mph14 km/h SouthwestRain
DateLowHighWindDayNight
November 148°F9°C60°F16°C9 mph14 km/h from SouthwestRainRain
November 247°F8°C54°F12°C9 mph14 km/h from WestRainMostly Cloudy
November 348°F9°C61°F16°C13 mph20 km/h from SouthwestDrizzleMostly Cloudy
November 455°F13°C59°F15°C10 mph16 km/h from SouthDrizzleCloudy
November 556°F13°C61°F16°C9 mph15 km/h from SouthDrizzleCloudy
November 652°F11°C58°F14°C12 mph20 km/h from SouthwestDrizzleMostly Cloudy
November 750°F10°C59°F15°C11 mph18 km/h from SouthDrizzleDrizzle

Yes

Low of 46°F8°C, High of 54°F12°C
Wind: 9 mph14 km/h
Precipitation: 73% rain

Support This Page