Week to see temperatures above 40°C with tropical nights, IPMA warns
From Monday, central and southern inland districts are on yellow alert, spreading to Trás-os-Montes on Tuesday and all mainland areas on Wednesday. By late week, highs will reach 43 ºC in the Tagus valley and Alentejo.
Published on 29/06/2026 - 9:18 GMT+2•Updated 10:24
The start of July will bring mainland Portugal a prolonged heatwave, with tropical nights, sending thermometers soaring to 43°C in some regions of the country.
According to the Portuguese Institute for Sea and Atmosphere (IPMA (source in Portuguese)), it is being driven by an anticyclone located to the north/northwest of the Azores archipelago, dragging in a mass of very hot, dry air.
The average temperature is expected to run 3°C to 7°C above normal across mainland Portugal, the IPMA says, highlighting increases of 5°C to 7°C in central regions and the Alentejo.
The 40°C threshold will be exceeded from Wednesday in the Alentejo districts, with the high temperatures then spreading to parts of the remaining regions towards the end of the week, meteorologists warn. In inland Alentejo, daytime highs will remain above 40°C from 1 to at least 7 July.
Over this period, eight districts are expected to reach or exceed 40°C: Braga, Coimbra, Castelo Branco, Santarém, Lisbon, Portalegre, Évora and Beja.
Unlike the heat episode at the end of May, the coast is also expected to be hit by the high temperatures, especially from Wednesday, with highs between 35°C and 38°C.
"Sea breezes along the coast in the afternoon will be weak, leading to unusually high temperatures in places that rarely experience them," the IPMA notes.
The situation will be compounded by tropical nights. Minimum temperatures will range between 12°C and 17°C at the beginning of the week, rising above 20°C in inland areas from Tuesday and in other regions from Thursday.
Yellow alerts issued
In view of what it describes as "a long spell of hot, dry weather", the IPMA has issued yellow alerts for the districts of Guarda, Castelo Branco, Portalegre, Évora and Beja from this Monday.
On Tuesday these alerts will be extended to Bragança and Vila Real, and will apply to the remaining mainland districts from Wednesday.
This weather pattern is, however, expected to be revised.
Because of the "long duration of this hot spell", the IPMA warns, "it is highly likely that the alert level will be raised in several districts in updates over the coming days".
