Today it will be tropical warm in the Netherlands due to the influx of warm air from Southern Europe. The air is also quite humid, making it feel even warmer. We investigated how this weather situation would look in a warmer world. What turns out? If the Netherlands warms up by an average of about 3 degrees more, a day like today could become up to 6 degrees warmer. So 37 degrees in De Bilt instead of 31 degrees. Extreme temperatures warm up much faster than the average. How is that possible?
Why is it so hot today?
The weather here is strongly determined by which direction the wind blows from. Today, a southerly wind is bringing warm air from Southern Europe towards the Netherlands (see animation in image 1). Moreover, the sun is high in the sky in June, and the solar radiation is therefore strong. Additionally, since the land is still relatively dry due to the dry spring, little water evaporates. Evaporation provides cooling, so the dry ground also contributes to the high temperatures today.
The weather today in a cooler and warmer climate
Nowadays, we are able to use our weather model to calculate todays weather in a cooler or warmer climate. This gives us an idea of the impact of climate change on the current weather situation and what we might expect in a warmer world. In image 2, you can see todays weather situation in both a cooler and a warmer climate. About 50 years ago, the Netherlands was on average 1.4 degrees cooler in spring. In this cooler climate, todays temperature would not have reached tropical values: not 31 degrees but about 2 degrees cooler. Tropical days around 1980 in De Bilt indeed occurred half as often. With an average warming of another three degrees (comparable to the highest KNMI23 climate scenario in 2100), todays temperature could have been over six degrees higher. The maximum temperature today would not have been 31 but 37 degrees. Combined with high humidity, it would feel even more muggy.
