Based on the weather in Northolt, Ealing, Greater London, United Kingdom as of October 21, 2016 10:02am local time

Why? Because it's cold. simple as that.
Current Conditions
Mostly Cloudy
Temp: 49.1°F9.5°C
Wind: 9.7 MPH15.7 KPH
Precipitation: None

Next 2 hours: Yes

Next 4 hours: Yes

Next 8 hours: Yes