Torrential downpours could cause flooding tomorrow.
A severe weather warning issued by the Met Office said some areas of West Yorkshire could get more than 50mm of rain and thunder storms in the space of three hours.
And it said the rain, which has been forecast to fall throughout the day, could cause flooding.
A statement from the chief forecaster said: “Large rainfall totals, falling in short periods and onto hard-baked ground, may lead to flooding locally, with hail and gusty winds an additional possibility.”
The Met Office has also issued a Level 2 heatwave warning.
It said temperatures of up to 25°C today and 23°C tomorrow could pose a risk to the very young, very old or those with chronic diseases.