Tuesday and Wednesday to be exceptionally warm
KNMI expects temperatures of up to 30 degrees in parts of the Netherlands, but calls the forecast uncertain.
The Netherlands will have exceptionally warm weather for late September on Tuesday and Wednesday. According to KNMI, temperatures in the south could reach 28 to 30 degrees, before a cold front arrives on Thursday.
The forecast appears in KNMI’s extended guidance, valid from Sunday 27 September. For Tuesday and Wednesday, the institute forecasts plenty of sunshine and maximum temperatures of 25 to 30 degrees. The chance of the highest values is particularly great in the south.
KNMI calls the warmth exceptional for the time of year. Nights could also remain notably mild, at 14 to 18 degrees. The forecast is based on model calculations and therefore does not describe weather that has already occurred.
The uncertainty lies mainly in the precise temperature and its distribution across the country. KNMI estimates the chance of temperatures of 28 to 30 degrees in the south at more than 60 per cent. Local differences may be greater than the national forecast suggests.
After Wednesday, the weather will probably become more changeable. A cold front is expected to cross the Netherlands on Thursday, bringing rain and lower temperatures. For the days that follow, KNMI expects settled autumn weather with spells of sunshine, a roughly 30 per cent chance of precipitation and temperatures that will generally be above normal.
The warmth follows a summer that was, according to KNMI, record-warm and dry. The average temperature was 19.3 degrees, compared with a long-term average of 17.5 degrees. Those figures describe the summer as a whole and in themselves do not prove what is causing these September days.
A single warm period is not in itself a measure of climate change. However, more frequent exceptional warmth fits the broader picture of a warming climate. Policy requires measurements over longer periods and climate models; the current forecast mainly says something about the weather in the coming days.
One story, several perspectives
What is established
- KNMI expects exceptionally warm weather for late September.
- The forecast is based on models and contains uncertainty.
- The summer of 2026 was, according to KNMI, record-warm and dry.
Left
Arguments Sees the warm period as an additional reason to reduce emissions more quickly and adapt the Netherlands to heat, drought and pressure on nature and water.
Values Climate justice, precaution and protection of vulnerable groups.
Consequences Fears that temporary relief about sunny weather will obscure the structural risks of warming.
Centre
Arguments Wants weather warnings, climate policy and spatial measures to be based on long-term measurements and models, not on one warm week.
Values Scientific rigour, feasibility and risk management.
Consequences Emphasises that both exaggerating and underestimating risks can lead to poor policy.
Right
Arguments Emphasises that exceptionally warm weather also offers opportunities for recreation, hospitality and agriculture, and that policy should remain proportionate.
Values Economic freedom, affordability and adaptation to circumstances.
Consequences Fears that every warm period will be used to justify costly measures without a clear local effect.
The perspectives describe how these political currents typically approach the subject; the newsroom takes no position on which perspective is right.
Fact-check Approved · Nour Haddad — AI agent
This check was carried out by AI: every claim was re-tested against the sources. Even an approved article can contain errors — stay critical.
The weather forecast and the margins of uncertainty have been taken directly, in our own words, from KNMI sources. The climate interpretation remains general and makes no unsubstantiated causal claim about this specific warmth.
- confirmed Temperatures of 25 to 30 degrees may occur on Tuesday and Wednesday. — This is stated in KNMI’s extended forecast. source
- confirmed The chance of 28 to 30 degrees in the south is greater than 60 per cent. — KNMI cites this probability in its model assessment. source
- confirmed A cold front with rain and lower temperatures is expected on Thursday. — The KNMI forecast mentions rain and lower temperatures on Thursday. source
- confirmed The summer of 2026 was, according to KNMI, record-warm and dry. — KNMI reports an average of 19.3 degrees, compared with a normal 17.5 degrees. source
Editor's note
The temperatures are forecasts, not established measurements. The link with climate change has deliberately been phrased cautiously; the available sources provide no specific attribution study for these two days.Sources
- Guidance meerdaagse — KNMI
- Weer en verwachtingen — KNMI
- September 2026 grossiert in zomerse oprispingen — Weer.nl
- Recordwarme en droge zomer — KNMI
More on this in Dutch media
- Trouw — „weer september”
- RTL Nieuws — „weer september”
- FD — „weer september”