Forecasters have warned of the risk of more flooding, travel disruption and power cuts with thunderstorms set to rumble on.
Those off for half-term have been told to beware of potential flash floods and sudden worsening of visibility amid heavy rain and balmy temperatures.
The Met Office has issued a yellow alert warning of thundery rain or showers which could bring local flooding to parts of southern England and Wales through Tuesday and into Wednesday morning.
Forecasters say there is a small chance that homes and businesses could be flooded or struck by lightning, causing damage to some buildings, and where flooding does occur there is a slight chance of delays or cancellations to train and bus services.
Spray and flooding could lead to difficult driving conditions and some road closures, while flooding or lightning strikes could cause power cuts in some areas.
A Met Office spokeswoman said: “It’s fairly normal weather for us to see thunderstorms through the summer months as temperatures warm up. Thunderstorms are caused by the warmer air.”
She said most summer rain comes in short, sharp, heavy showers, adding that what is unusual is the longevity of this period – with the risk of thundery showers lasting through the week.
Heavy showers and #thunderstorms are forecast across some parts of the UK today. Heavy #rain, frequent #lightning and gusty winds could lead to some local disruption at times. Stay #weatheraware https://t.co/bWJhTxX452 pic.twitter.com/GNl9TXq5pw— Met Office (@metoffice) May 29, 2018
While some places will escape the worst of the rain, or even manage to stay largely dry, some rain will be heavy and up to 1.2in (30mm) could fall in an hour or less and 1.6in-2in (40mm-50mm) could fall in a couple of hours.
More than 30 flood alerts are in place for England on Tuesday.
One elderly man lost his life in the early hours of Monday when his vehicle became submerged in Walsall, and multiple rescues had to be carried out from cars, buses and homes on Sunday, the West Midlands Fire and Rescue Service technical rescue unit said.
Scattered heavy showers and #thunderstorms will develop through the rest of Tuesday and into Wednesday morning. Frequent #lightning, heavy #rain and localised flooding is possible. Stay #Weatheraware pic.twitter.com/yTSV5MnrvR— Met Office (@metoffice) May 29, 2018
Cavendish in Suffolk was the warmest recorded spot on Monday, peaking at 27.3C (81.1F), a few degrees shy of the April high of 29.1c (84.4F) in central London.
Scotland, Wales and Northern Ireland all enjoyed their hottest days of 2018 on Monday, with Dunstaffnage in Argyll reaching 27.1C (80.8F), Hawarden Airport in Clwyd reaching 24.9C (76.8F), and Castlederg in County Tyrone reaching 25.1C (77.2F).
Kate Marks, Environment Agency flood duty manager, said: “Further heavy showers and scattered thunderstorms remain today (Tuesday) and overnight into tomorrow (Wednesday) morning which bring a risk of localised surface water and river flooding.
“The main risk is across Southern England, East Anglia and parts of the South Midlands, with urban areas most likely to see the impacts.
“Our thoughts are with those who have been affected by the flooding over the bank holiday weekend and our teams are working with those communities who have experienced flooding.
“We are continuing to check and operate defences and we are supporting local authorities in responding to surface water flooding.
“We remind people not to drive through flood water as just 30cm can move your car, and to check our active alerts and warnings, which are updated every 15 minutes, online at www.gov.uk/check-flood-risk or by calling 0345 988 1188.”