The Met Office has extended its weather warning of heavy rain across south west Hertfordshire to include Saturday.
The yellow warning for Friday, February 7, was issued on Monday - and warns of the possibility of localised flooding and disruption to transport.
The warning has now been extended to cover Saturday.
The yellow alert is the lowest level of severe weather warning, and asks members of the public to "be prepared for adverse weather".
The Met Office’s chief forecaster said: "Another area of low pressure will bring spells of heavy rain to during Thursday and early Friday, with 15 to 25mm of rain falling widely and 40mm locally."
"A further Atlantic frontal system will bring a band of rain quickly eastwards during Friday night and early Saturday, with the heaviest rain again likely to be across parts of southern England, followed in turn by heavy showers."