A Met Office yellow weather warning for rain, isolated thunderstorms and lightning has been enforced across Lincoln and Lincolnshire from Thursday.
The warning, which affects most areas in the East Midlands, applies to the period between 6am on Thursday, July 6 and 6am on Friday, July 7.
Warnings state that flooding may be likely in some areas and those travelling should be prepared for possible transport disruption.
Met Office forecasters said: “Isolated thunderstorms are likely to develop across parts of England and Wales from Thursday morning, before clearing east early on Friday.
“While these storms may miss many places, where they do develop intense downpours are likely, bringing a low risk of sudden flooding of roads, transport routes, homes and businesses.
“Lightning and hail may be additional hazards.”