The KNMI weather bureau has issued a code yellow weather warning for the south of the country on Thursday, warning that the temperature could reach 30 degrees in places.

In particular, people with chronic health conditions, the overweight and the elderly should take care to keep cool and drink enough, public health institute RIVM said.

The sun’s rays are also extremely strong at the moment and skin can burn with as little as 15 minutes exposure, the RIVM warned.

The picture will be similar on Friday, although there may be storms in the south towards evening. Saturday will be cooler, with more rain and some sunny spells. Sunday too will be wet with some sunshine, and temperatures no higher than 24 Celsius.

The public health institute RIVM is warning swimmers to be aware of the presence of blue-green algae and botulism in some lakes, which develops in high temperatures and where the water is relatively still.

Swimmers can check the conditions at their favourite swimming place via zwemwater.nl which monitors 770 official swimming sites.