The Met Office has issued a thunderstorm warning for the north-east.
The forecaster said some places are likely to see severe thunderstorms, and scattered heavy showers are expected to cause some transport disruption and flooding.
The warning will come into effect at midnight on Monday and will remain in place until 23.59 on Tuesday.
A statement from the Met Office said: “Areas of thunderstorms are increasingly likely to develop over the south of the UK or nearby continent late in the weekend or early next week, and will generally track north or north-westwards, potentially affecting all parts of the UK at some points during this period.
“While the most intense thunderstorms, in some instances associated with large hail, will most probably be those triggered by the high temperatures of the day over England and Wales, other areas of storms producing heavy rainfall and frequent lightning could reach further north at times over Scotland and Northern Ireland.
“These could occur at any time of the day. Of the area highlighted, at present the west of Northern Ireland and west of Scotland seem less likely to be affected than other areas, but still could not be ruled out. Where the storms occur, rainfall totals of 30-40 mm could fall in an hour, with some locations potentially receiving 60-80 mm in 3 hours, although these will be fairly isolated.”