A yellow weather warning has been issued for fog this evening.
Forecaster at the Met Office say fog patches are expected to form during Tuesday night, becoming dense and freezing in places by dawn on Wednesday, particularly in river valleys with visibility less than 100 metres at times.
Fog will thin slowly later Wednesday morning.
The warning will be in force across Gloucestershire from 10pm this evening until 12pm on Wednesday.
Image: © Copyright Philip Halling