The temperature is set to top 30 Celsius in most of the country by the middle of this week, weather forecasters say, with the drought set to continue well into the second half of the month.

Monday will be between 20 and 26 degrees and there could be some light showers in the north. The sunshine will dominate as the week continues as the temperature tops 30 Celsius nationwide, with little wind, the KNMI weather bureau said.

‘The way things look at the moment, it will stay that way until the weekend at least,’ weather website Weerplaza said.

People looking forward to a refreshing dip in a freshwater lake are also being warned to be on the look out for harmful algae blooms, which can lead to skin irritations and upset stomachs.

The government’s water department said on Monday that swimmers should check warning boards and the website of approved swimming spots for further information about the presence of the blue-green algae which thrives in warm, slow-moving waters that are rich in nutrients from sources such as fertiliser runoff.

The pending heatwave means no end is yet in sight for the drought, which led the government to declare an official water shortage last week.

Water levels on the Rhine, the Meuse and the IJssel are now so low that shipping is being hampered but as yet, the government has not brought in a hose pipe ban.