Latest ever 'tropical day' in NL; 30.2°C in De Bilt

At 2:20 p.m., temperatures climbed to 30.2 degrees at the national weather station in De Bilt, making Tuesday officially a tropical day. This is the latest in the year that temperatures in the Netherlands topped 30 degrees since temperature measurements started in 1901, Weeronline reported.

The previous record for latest tropical day was 14 September 2016, when it measured 31.4 degrees in De Bilt. Today is the sixth time since 1901 that the temperature in De Bilt rose to tropical values in September. 

Earlier on Tuesday, it officially became the hottest September 15 ever measured in the Netherlands - the ninth day heat record broken so far this year. With thermometers reading 30.3 degrees Celsius in The Hague and surrounds, today is also the hottest Budget Day in Dutch history. The previous record was 28.7 degrees on 19 September 1961. 

Late in the morning, public health institute RIVM also said there was a risk of smog in many parts of the country, especially from Schiphol southeast to Roermond, around the IJsselmeer and Markermeer lakes, east of the Netherlands from Zwolle to the German border. The heaviest amount of pollution was expected in the afternoon, and was likely to cause coughing, shortness of breath, worsening of asthma symptoms, and also irritation to the eyes nose and throat.

The smog was likely to dissipate later on Tuesday evening, with air quality likely to improve as the air temperature cools down and the wind shifts towards the north.

This unseasonable heat will subside in the coming days. On Wednesday, thermometers will climb to between 23 and 28 degrees Celsius, and from Thursday maximums will range between 20 and 25 degrees. The days will be sunny and there is little chance of rain.