The Met Office has issued a yellow (thunderstorm) weather warning for Oxfordshire tomorrow (Thursday June 23).
Temperatures are still expected to be in the mid twenties but thunderstorms are expected during the day.
The Met Office said: "People can expect thunderstorms and torrential downpours, which may cause travel disruption and, in a few places, flooding.
"There is also a small chance that flooding could cause danger to life in some places."