The Met Office has issued a yellow weather warning for heavy rain, with up to 30mm – just over an inch – likely to fall in places.
The weather warning runs from 10am until 6pm tonight, and the Met’s forecast for Brighton shows heavy rain falling continually until 4pm.
The chief forecaster says: “Rain will become persistent, with some heavy bursts at times. 10 to 20 mm rain is likely to fall widely, with up to 30 mm in a few places.
“Given saturated ground, this may lead to some localised flooding.
“The rain will slowly clear from the west later this afternoon and early evening.”