Seven Interior Districts Face Early-Week Heat Alert as Thermometers Near 38 °C

Portugal’s normally languid summer rhythm is about to quicken again, as the national weather service warns of another run of scorching afternoons across the country’s interior. From the Trás-os-Montes hills to the Alentejo plains, seven districts are now under heat alerts that stretch at least through Tuesday evening, with daytime highs expected to flirt with 38 °C in several cities. Coastal residents will feel only a muted version of the heat, yet anyone planning travel inland this week should be ready for temperatures more typical of Spain’s Meseta than of breezy Atlantic Portugal.

Interior braces for a short but sharp spike

The Portuguese Institute for Sea and Atmosphere (IPMA) has issued its yellow notice—the first rung on the agency’s three-tier warning system—for Bragança, Guarda, Vila Real, Castelo Branco, Portalegre, Évora and Beja. The advisory begins at the start of the day and is set to lapse at 18:00 on Tuesday, except in Bragança and Vila Real, where it will linger until late Wednesday. Forecast models point to mostly clear skies, a slight overnight cool-off, and then a marked rise in maximum temperatures once the sun climbs. Among larger towns, Castelo Branco and Évora are expected to lead the national heat table at 38 °C, with surrounding districts only a degree or two behind.

Why inland Portugal heats up so quickly

Foreigners familiar with Lisbon’s afternoon sea breeze or Porto’s misty mornings often underestimate how abrupt the temperature jump can be once they head east. The interior sits beyond the Serra de Estrela and other coastal ranges that block marine air, leaving valleys exposed to dry continental winds sweeping off Spain. Rock-strewn soils warm rapidly under midsummer sunshine, and when twilight arrives the lack of humidity means very little heat escapes. The result is an amplified diurnal range: coolish dawns followed by furnace-like afternoons that can surprise first-time visitors.

The invisible danger: ultraviolet radiation

While thermometers attract the headlines, IPMA’s ultraviolet index remains firmly in the “very high” bracket this week for mainland Portugal and Madeira, with an “extreme” rating flagged for several districts on Monday and Tuesday. Thin cloud cover offers minimal protection, so dermatologists recommend slipping errands to before 11:00 or after 17:00, wearing UV-rated sunglasses and broad-brimmed hats, and re-applying factor-30 (or higher) sunscreen every two hours. Children and newcomers with fair skin are at particular risk of sunburn in as little as 15 minutes.

Staying comfortable if your home lacks air-conditioning

Many historic apartments popular with expats rely on thick stone walls rather than mechanical cooling. During heat spells, close shutters by mid-morning, open windows only when outside air becomes cooler than indoors, and run a fan across a shallow tray of ice for makeshift evaporative relief. Portuguese tap water is safe nationwide, but pharmacies also stock electrolyte tablets that help replace minerals lost through perspiration. Should you feel dizzy or nauseous, the 24-hour English-speaking health helpline (808 24 24 24) can advise on whether a clinic visit is needed.

Wildfire season overlaps the heat

The civil-protection authority has stepped up patrols as cured grasses begin to brown. Open-air grilling, agricultural burn-offs and off-road vehicle use may face temporary restrictions when the mercury peaks, so check municipal websites or the Proteção Civil mobile app before planning countryside excursions.

A hint of relief by mid-week

Current computer runs indicate a weak north-westerly flow arriving late Wednesday, shaving two or three degrees off daytime highs for most regions. Nights will feel noticeably fresher first, followed by slightly cooler afternoons. Until then, a blend of local know-how—early starts, long lunches indoors, and a re-discovered appreciation for Portugal’s excellent iced coffee—should help newcomers navigate a classic Iberian heat burst without too much discomfort.