Today will be mainly fine but developing clouds may bring isolated showers and thunderstorms in the afternoon in the mountains and in some areas inland.
Temperatures will reach 40 C inland, 34 C in the south, east and north coasts and 31 C in the west coast and the mountains.
A yellow alert for extremely high temperatures is in force from 1 pm to 5 pm for the third day in a row. The Met Office warns that people who are the most vulnerable during these hours are the elderly and the very young.
Tonight will be mainly fine with sparse fog and low clouds likely to form locally. Temperatures tonight will edge down to 24 C inland and on the coast and 21 C in the mountains.
Tuesday will be mainly fine but developing clouds may bring isolated showers and/or thunderstorms in the afternoon in the mountains and inland.
Wednesday and Thursday will be mainly fine with increased cloud observed locally in the afternoon in the mountains and inland.
Temperatures will not shift significantly on Tuesday but will remain above average for the time of year, especially inland and in the mountains, while on Wednesday we will see a rise in temperature.
However, it will edge down slightly on Thursday to return to Tuesday levels.