Twelve of mainland Portugal's 18 districts have been placed under a red warning, the most severe meteorological alert, as a persistent and extreme heat wave settles over the country through Saturday.
The districts of Beja, Évora, Portalegre, Santarém, Lisbon, and Setúbal are on red alert Thursday, with Aveiro, Braga, Porto, Viana do Castelo, Coimbra, and Leiria joining on Friday. The remaining six districts are under an orange warning for moderate to high risk.
Maximum temperatures are forecast to hit 41 to 44°C in the Tagus valley and Alentejo region, with highs between 35 and 41°C across the rest of the country. The situation is particularly unusual for coastal regions where weak sea breezes are failing to provide relief, making this a rare event for some areas.
Overnight lows will not dip below 24 to 28°C for several consecutive nights, including in Greater Lisbon. The extreme heat is expected to last for at least a full week as an anticyclone near the Azores drives the weather pattern.
The government has declared a formal alert situation starting midnight Friday. This triggers a ban on access to designated forest areas, a prohibition on controlled burns and agricultural waste burning, and a ban on machinery use in forests unless for firefighting operations. Authorities have also issued health guidance urging hydration, avoidance of sun exposure between 11:00 and 17:00, and special attention to vulnerable populations.