Will Belgium’s brief return to summer disrupt the start of the school year?
Belgium’s Royal Meteorological Institute forecasts a brief rise in temperatures on Wednesday 26 and Thursday 27 August 2026, with local highs reaching 30°C before thunderstorms bring cooler conditions.
In 30 seconds
- The IRM forecast highs of 26°C or 27°C across much of Belgium on Wednesday 26 August.
- Thursday’s maxima could range from 25°C at the coast and in the Hautes-Fagnes to 30°C in Campine.
- Intense thundery showers and strong gusts were possible late Thursday.
- Friday was expected to be cooler, with maxima between 17°C and 23°C.
Belgium’s Royal Meteorological Institute (IRM/KMI) forecast on Tuesday 25 August that warmer, unstable air would lift temperatures to 26°C or 27°C across much of the country on Wednesday and as high as 30°C in on Thursday, before thunderstorms and a marked cooling on Friday. For families returning to school in the , the practical message is straightforward: pack water and light clothing, add a hat and sunscreen where outdoor activities are planned, and keep a rain jacket close because the petit coup de chaud will come with a risk of showers and thunder.
The warm spell is short rather than a new sustained heatwave. In its noon update, the IRM expected Wednesday’s maxima to range from about 23°C in the Hautes-Fagnes to 25°C at the coast and 26°C or 27°C elsewhere. Thursday could bring 25°C at the coast and in the Hautes-Fagnes and 30°C in Campine. The institute also warned that showers late on Thursday could become intense and thundery, with strong gusts possible. Friday’s expected range of 17°C to 23°C illustrates how quickly conditions may change.
That mixed forecast matters at the school gate. Children may leave home during a mild morning, sit in a warm classroom or playground by afternoon and encounter heavy rain on the journey back. Parents should therefore rely on the latest IRM/KMI forecast and warnings rather than treating a single temperature shown several days earlier as fixed. School-specific decisions about sports, excursions, classroom ventilation or access to water come from the school or its organising authority, not from a general national weather bulletin.
What should families do?
A refillable water bottle is the most useful addition to the school bag. The federal FPS/SPF Public Health advises people to drink more water than usual during hot weather, limit strenuous physical activity during the warmest hours, close curtains or shutters during the day and ventilate when it becomes cooler at night. Its guidance gives particular attention to children, older people and those with chronic health conditions.
For pupils spending time outside, the SPF also recommends protective clothing, a hat and suitable sunscreen. Its sun-safety guidance says children are especially sensitive to ultraviolet exposure and advises avoiding the strongest summer sun, generally between noon and 4pm under daylight-saving time. Sunscreen should complement shade and clothing rather than be treated as complete protection.
Parents may also want to place a light waterproof layer in the bag and check whether the school has changed an outdoor sports session. If a child develops unusual weakness, intense thirst, dizziness, headache, nausea or breathing difficulty, move them somewhere cool, stop physical activity and seek medical advice. Call 112 for an emergency; the number works throughout Belgium and the European Union.
Who decides what happens at school?
Belgium’s linguistic organisation can be confusing for newcomers. French-language schools in and Wallonia generally follow the Fédération Wallonie-Bruxelles and use terms such as rentrée, école communale and pouvoir organisateur. Dutch-language schools follow the , where parents will encounter schooljaar, gemeenteschool and schoolbestuur. The calendars are not identical: French-language pupils had already returned when this warm interval arrived, whereas most Flemish schools were still preparing for their usual September start.
For a school-level question, contact the secretariat or direction first. For municipal schools, the relevant commune in French or gemeente in Dutch may publish local information. Brussels residents should remember that the is only one of the capital’s 19 communes: a family in Schaerbeek/Schaarbeek, Ixelles/Elsene or Anderlecht should consult that municipality and its school rather than the brussels.be portal by default.
There is no indication in the reviewed sources of a nationwide order closing schools or altering class times for this episode. Arrangements can differ because buildings, shaded playgrounds and ventilation vary considerably. The sensible approach is to follow the school’s own communication channel—email, Smartschool, an online parent platform or a message from the direction—while using IRM/KMI warnings for the weather itself.
More than an awkwardly timed warm day
The brief rise arrives after an exceptional Belgian summer. In a provisional assessment using observations through 23 August, the IRM said summer 2026 was on course to be the warmest since national records began in 1833. It estimated a seasonal average of 20.3°C, compared with the previous record of 19.9°C in 2018, and had already counted 15 days reaching at least 30°C—three times the normal five. Those provisional figures require confirmation after the month closes, but they put this week’s weather into a larger pattern of repeated heat and dryness.
Belgium’s response is divided across federal, regional and community institutions. The federal remains in its annual vigilance period from 15 May to 30 September, while federated authorities implement their own measures when warning thresholds are reached. Wallonia directs residents to regional guidance and the AVIQ; Brussels municipalities and CPAS/OCMW services provide local help, including support for vulnerable or isolated residents. The terminology changes by language, but the core advice is consistent: hydrate, reduce exposure during the hottest hours, cool buildings intelligently and watch people who may struggle to regulate their temperature.
The immediate uncertainty concerns the timing and intensity of Thursday’s thunderstorms. Families should check the IRM/KMI app or website on Thursday morning and again before the afternoon journey. The heat should ease on Friday, with unsettled but seasonable weather then expected into early September. This is best treated as a short, humid and changeable rentrée complication—not a reason for alarm, but a useful rehearsal for warm school days that Belgium is likely to face more often.
What to do
For school on Wednesday 26 and Thursday 27 August, send children with drinking water and light clothing, and add rain protection because thunderstorms and strong gusts may develop late Thursday. Check messages from the school, commune or gemeente for any changes to outdoor activities or daily arrangements. Conditions will not be uniform: Thursday could reach 30°C in Campine but remain around 25°C at the coast and in the Hautes-Fagnes. Friday should be cooler, with forecast highs of 17°C to 23°C, so review clothing again rather than planning for sustained heat.
Impact
Regional — Campine could record the highest temperature, around 30°C, while the coast and Hautes-Fagnes were forecast to remain nearer 25°C on Thursday. French-language schools in Brussels and Wallonia were already in session, making the timing more immediately relevant there.
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Voices & reactions
What the main actors are doing
Reported positions, summarised — not direct quotationsFamilies seeking a simple forecast
Parents chiefly need a clear packing and travel decision: water, light clothing, sun protection and a rain layer. From this perspective, the forecast is a manageable two-day disruption rather than a reason to alter normal family routines.
Schools and public-health authorities
School leaders and health services must consider indoor temperature, playground shade, physical activity and vulnerable children rather than the headline maximum alone. Their response may therefore differ by building, pupil population and municipality.
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This story was assembled from verified evidence, with its sources and reasoning recorded as it was written.