Mastodawn

Kees van der Leun 5d ago

I'm afraid that many here in the Netherlands don't fully understand yet how hot the coming days will be. We're heading for 4 consecutive days like this (map for Wednesday). 35°C really feels different than 30°C!
The weirdest part is that this already happens in June.
(It's climate change at work)
1/8

Kees van der Leun 5d ago

Four consecutive very hot days mean that homes gradually get hotter. Around 75% of our homes doesn't have a cooling system, despite the rapid growth of air conditioning since 2019. We never needed one before climate change hit hard.
2/8

Kees van der Leun 5d ago

Meteorological institute @knmi now predicts that the nights will get very hot too. For the night from Thursday to Friday, they expect a low temperature of 24°C. That'd beat the previous record from July 2018 by 1.5°C!
Night ventilation won't cool our homes to a comfortable level in such a night.
3/8

Kees van der Leun 5d ago

This coming Friday will be the 9th day of our national heatwave (consecutive days above 25°C with at least three above 30°C). We've never seen such a long heatwave before July (8 days in 1936 and 1976), and it won't be over yet on Friday.
4/8

Kees van der Leun 5d ago

Five or six 'tropical days' (above 30°C) in June is very rare for the center of the country (De Bilt). I don't have the stats at hand (I bet @Datagraver does), but it's more typical for the summer as a whole, with most occurring in July and August.
5/8

Kees van der Leun 5d ago

The absolute high temperatures that we'll experience in the coming days are extreme, too. For 75 years, we knew that the highest temperature ever recorded was 38.6°C in Warnsveld (1944). Then came July 2019, and we crashed forward to 40.7°C (Gilze Rijen, 25 July).
Now, 39-40°C is already possible again.
6/8

Kees van der Leun 5d ago

In short, this is a weirdly extreme event, only possible due to climate change. As @tinuspulles.bsky.social pointed out, explanations like 'heat dome' and 'jet stream' are about mechanisms. The driving force behind all of this is global warming, largely due to burning fossil fuels.
7/8

Kees van der Leun 5d ago

Of course, people in other countries are experiencing much higher temperatures with much less means to protect themselves. But now, it's coming home to our relatively rich (and high emission) part of the world, too.

We need bold and rapid climate action now!
(8/8, for now).

Kees van der Leun

There we go. Sweaty morning commute on the bicycle. Temperature already 7°C up from its early morning low by 08:30.
Found the office at 27.5°C; keeping the shading down at night is not allowed here, so the evening sun heated it up nicely. Cooling it down a bit for the colleagues now :)
+1

Kees van der Leun 4d ago

Day 1: high temperatures ranging from 30°C in the north of the Netherlands via 34°C in the center to 36°C in the south.
Looks like Friday will be the most extreme now.
+2

Kees van der Leun 3d ago

After 126 years, the hottest June day ever (24-hour average) here in the central Netherlands was Wednesday, and the #4 was yesterday. And today, we'll have a new #1, by far. And tomorrow may well enter the top-10, too.

Kees van der Leun 2d ago

Today's 39.4°C (Ell, Limburg) is by far the highest June temperature ever measured anywhere in the Netherlands. The previous record was crushed by 1.5°C! https://www.weeronline.nl/nieuws/26-6-2026-hoogste-juni-temperatuur-ooit-gemeten

Kees van der Leun 2d ago

Until yesterday, nightly temperature in the central Netherlands had never stayed above 19.5°C in the 126-year record. Yesterday: 21.3°C. Today: 21.2°C. Tomorrow: probably even higher.

Kees van der Leun 1d ago

Until this week, the 24-hour average temperature in June had never in 126 years hit 27°C at @knmi.nl's main station De Bilt, the Netherlands.
Now, the record is yesterday's 28.8°C, the #2 is last Wednesday, the #7 is Thursday, and today is marching up in the top-10 as well.

Kees van der Leun 1d ago

Today is the 11th and hopefully last day of the Netherlands' longest pre-July national heatwave ever. Relief!
High of 27°C expected here in the centre, but still 32 in the East.

Kees van der Leun 1d ago

After this brutal heatwave, June will end up as the second warmest on record in the Netherlands, right behind 2023, and ahead of 2025.
Average temperature 19.2°C, above the already warmed 1991-2020 average for July and August.

Kees van der Leun 1d ago

The second half of June is absurdly hot, here in the Netherlands. Its average temperature of 23.3°C will beat the previous record by 3 degrees!
It's also hotter than any full month ever recorded here (July 2006 had 22.3°C).
#heatwave #ClimateChange #extremeweather

@Sustainable2050
6 from the top 10 in the last 9 years.

Regendans 1d ago

Wondering where the numbers came from. Appears to be this one : https://weerstatistieken.nl/

Weerstatistieken KNMI - Actuele weergegevens

Weerstatistieken KNMI

@Sustainable2050 44 in paris, talk to shell ...

Nick Rogers 9h ago

@Sustainable2050

That’s very warm.

Record June temperatures here in Australia too. What will Summer bring?

https://www.theguardian.com/australia-news/2026/jun/16/australia-climate-change-crisis-warmest-start-to-winter-for-century

‘Something is changing’: Sydney records warmest run of June days in more than a century

Temperatures topped 20C on Tuesday for the 10th consecutive day, a streak not seen since 1919

The Guardian

Rob Larter 1d ago

@Sustainable2050
Even though it may feel like a relief, those temperatures are still an anomaly of +5 to +7°C compared to the average June daily maximum in the Netherlands. Our view of what's normal is being shifted.

Dr Susi Arnott 1d ago

@PoLaRobs @Sustainable2050
How to use this shocking heat storm to promote decarbonisation? Here in UK it might still be possible, but already slipping into squabbles about jobs in our (shrinking, dying, and largely foreign-owned) fossil fuel extraction industry

martin lentink 🇪🇺 🇺🇦📎1d ago

@Sustainable2050 5 of the top ten were in the last 7 years...

Pieter Kuiper 🌍🇳🇱2d ago

@Sustainable2050
The sky is clear, so temperatures should go down now but it stays lukewarm and muggy outside. Almost no wind (and I am close to the coast).

That must be due to all the greenhouse gases in the atmosphere. That prevents the heat from radiating out to space.

Peter Blok 2d ago

@Sustainable2050 At least people are not freezing to death, that's a plus. In the short run.

@Sustainable2050 this night (vr-za) is much stickier than yesterday (do-vr) in the east. Yesterday there was a wind and fresh air from 21.00 now at 3.30 no wind and finally one degree cooler outside. VERY humid.

WGAvanDijk 2d ago

@Sustainable2050
Last night, temperature around our house (Middle Limbrg) did not go below 27C. Thanks to roller-shades, curtains, good isolation, we managed to keep it inside at 26C. But opening windows and doors at night or early in the morning did not help to cool down.

Enjoy this coolness. This will be the coldest summer for the rest of our lives, the temperatures will only go higher.

@WGAvanDijk @Sustainable2050 Hier in Twente ook niet onder de 26 graden geweest vannacht. 7graden warmer dan nacht van do-vr.

@Sustainable2050 Saturday the 4th of july demonstration on the highway A12 near Utrecht. To protest the tax cuts for mega fossile energy users.
https://a12blokkade.nl/

A12-blokkade | 4 juli 2026 | Stop Fossiele Subsidies

€39,4 - 46,4 miljard aan fossiele subsidies naar grote vervuilende bedrijven. De crisis is nu en wij kunnen én moeten samen het tij keren!

A12-blokkade

Nick Rogers 3d ago

@Sustainable2050
Australian summer temperatures in the Netherlands! That must be a shock.

Meanwhile, on the other side of the planet, Australia’s highest ski field (2000m above sea level), which would historically be under at least a metre or two of snow right now, has almost none.

@Sustainable2050
Vandaar dat ik om 06.00 opgestaan ben. Verschil twee uur later duidelijk te voelen. Planten die geel blad kregen water gegeven met water uit regenton.

Rihards Olups 5d ago

@Sustainable2050 «not allowed»?