The KNMI weather bureau on Tuesday issued a code yellow weather warning, stating that heavy storms will move over most of the country on Tuesday afternoon.

So much rain may fall in places that there will be flash flooding and other problems in some areas, the KNMI said.

The storms are expected to hit the south of the country around 2pm and move slowly northwards. The weather warning will apply nationwide from 4pm and will last into the evening.

Weather website Weeronline warns that the amount of rain which will fall could be more than the average for an entire month. In addition, hailstones of up to four centimetres across may fall in places.

Most problems are expected to hit the south of the country, which was also seriously affected by storms on Sunday evening.

The temperature on Tuesday is expected to range from 28 degrees in coastal regions to 31 degrees in the south. Monday was the first regional tropical day of the year, after the temperature broke the 30 degree barrier in the far east of the country.

The temperatures will be slightly cooler, with more cloud and some showers, from Wednesday onwards.

Records

Both the KNMI and weather bureau Weerplaza said two days ago that May 2018 is set to go on record as the warmest May since temperature records began in 1706.

The warmest May on record dates back to 1889 with an average temperature of 16 degrees, but May 2018 is currently on an average of 16.4 degrees, the weather bureaus said.

The average temperature in a normal May is around 13 degrees.