There is a continued danger of flash flooding from an ensemble of rain that could expand across the country.
The storms could generate unsafe driving conditions with reduced visibility and spray from standing water.
The Met Office warning said: “Some of the showers would become thundery, leading to slow-moving systems with downpours.”
The Yellow Weather Warning said: “Some locations will miss these but where they do occur, please be aware of possible localised flooding and disruption to travel.
“Lightning could be an additional hazard.”
The Met Office’s Chief Forecaster said: “As with most recent days, temperatures will rise, triggering some heavy downpours.
“These may locally produce 15mm to 25mm of rainfall in an hour, bringing the risk of flooding, especially if affecting urban areas.”
The bad weather is anticipated to continue on Wednesday with forecasts of additional dispersed heavy thundery showers leading to potential flooding in urban areas.
Forecaster Steven Keats said: “The area of low pressure responsible is not moving very fast so it will be similar weather all week.
“Drivers should be aware that there will be some quite tricky driving conditions about. There will be lots of spray and some flooding.
“As always, if you cannot see the road surface, do not drive through it.”
