A yellow warning for thunderstorms has been issued across Slough, Windsor and Maidenhead.
The Met Office said the region could see heavy showers and thunderstorms from 7pm onwards tonight (Wednesday).
The weather disruption is expected until 3am.
The amount of rainfall will vary across the south of England but the Met Office said the wettest spots could see around 25mm of rain inside an hour.
Spray and sudden flooding could lead to difficult driving conditions and public transport could be disrupted if lightning strikes occur.