The met office has issued a new orange alert, warning that heavy thunderstorms likely associated with hail are expected to affect inland, mountainous and possibly southeastern and eastern coastal areas.
The precipitation rate may exceed 55 millimeters per hour, it added.
The alert is in force from 12 noon to 6 pm on Tuesday. It is the fourth orange alert since late last week.
Earlier on Tuesday, the met office said weak low pressure and an unstable air mass are continuing to affect the area bringing more thunderstorms and scattered showers in the afternoons over the next few days.
The met office said that after local light fog lifts, Tuesday will be mainly fine. But clouds will develop as from midday and in the early afternoon leading to scattered showers and thunderstorms in the mountains, inland and on the east coasts.
Thunderstorms may be accompanied by hail.
Temperatures will be 33 C inland, around 29 C on the west coasts, around 31 C on the remaining coasts and around 24 C in the mountains.
Tonight will be mainly fine with increased low cloud or light fog. Temperatures will drop to 20 C inland, around 21 C on the coasts and 12 C in the mountains.
On Wednesday clouds will develop from midday and in the afternoon that will lead to isolated showers and thunderstorms in the mountains, inland and possibly on the south east and east coasts.
Temperatures are expected to remain at the same levels which are slightly below average for the time of year.
Thursday and Friday will be mainly fine but clouds will fall at midday and in the afternoon which will lead to scattered showers and thunderstorms in the mountains and inland.
Temperatures will edge up on Thursday, remaining at the same levels on Friday at close to average for the time of year.