Thunderstorms have hit south-west England and Wales, providing a brief respite from sweltering temperatures and dry weather that have raised the prospects of a hosepipe ban.

Households have been urged to conserve supplies amid near record-breaking temperatures in June, while over the weekend Northern Ireland became the first part of the UK to issue a hosepipe ban.

The Met Office gave its first ever thunderstorm warning on Sunday amid fears that torrential rain, hail and lightning could lead to difficult driving conditions, road closures and flood damage to homes and businesses.

The thunderstorm warnings were only introduced last month in recognition that there is “a significant difference between the impacts of heavy rain in winter and those from thunderstorms”. A new weather alert was introduced by the Met Office for lightning at the same time.

About 30-40mm of rain was expected in places but on Monday the thunderstorms are expected to have all but cleared, leaving most of the country free to bask in sunnier weather.

Helen Roberts, meteorologist at the Met Office, said: “It could be another day of very warm or hot sunshine. There will be some cloud across the south-west corner of the country where they have been showers [on Sunday] so that diminishes things a little bit but otherwise [there will be] lots more sunshine.”

With the rain expected to be short-lived, Welsh Water and South West Water encouraged householders to cut water consumption where they could.

Spikes in demand at morning and evening peak times have forced utility companies to pump billions more litres of water into the system. The companies say it is often being used by customers as fast as it is supplied.

Northern Ireland Water said it was putting 25% more water into the network than is normal for this time of year.

Even while parts of the south-west and Wales were under deluge on Sunday, elsewhere the heatwave continued, with a high of 32.2C (89.9F) recorded in Gosport, Hampshire by mid-afternoon.

Roberts said there was no reason the mercury should not reach a similar level on Sunday in southern or central England, or the Midlands, with a similar pattern expected to continue for the next few days.

“There will certainly be plenty more very warm sunshine for the rest of the week, with temperatures in the high 20s if not low 30s,” she said.