IPMA warns of temperatures above 40C and tropical nights this week
From Monday, central and southern inland districts are on yellow alert, extending to Trás-os-Montes on Tuesday and the rest of mainland Portugal on Wednesday. By the weekend, temperatures in the Tagus valley and Alentejo may reach 43 ºC.
Published on 29/06/2026 - 9:18 GMT+2•Updated 11:11
The start of July brings mainland Portugal a prolonged heatwave, with the formation of tropical nights, and will send thermometers soaring to 43°C in some parts of the country.
According to the Portuguese Institute for Sea and Atmosphere (IPMA (source in Portuguese)), the phenomenon is being driven by an "anticyclone located to the north/northwest of the Azores archipelago" that will pull in a "mass of very hot, dry air".
Average temperatures are expected to be 3°C to 7°C above normal across mainland Portugal, IPMA says, highlighting rises of 5°C to 7°C in the Centre and Alentejo regions.
The 40°C threshold will be exceeded from Wednesday in the Alentejo districts, with high temperatures then spreading to parts of the remaining regions by the end of the week, meteorologists warn. In the Alentejo interior, daytime highs will stay above 40°C from 1 to 7 July at least.
During this period, eight districts will reach or exceed the 40°C mark: Braga, Coimbra, Castelo Branco, Santarém, Lisbon, Portalegre, Évora and Beja.
Unlike what happened during the late-May hot spell, 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 are not used to them", IPMA notes.
The situation will be exacerbated by tropical nights. Night-time lows will range between 12°C and 17°C at the start of the week, and are expected to exceed 20°C in the interior from Tuesday and in other regions from Thursday.
Yellow alerts issued
Given what it describes as "a long period of hot, dry weather", IPMA has issued yellow alerts for the districts of Guarda, Castelo Branco, Portalegre, Évora and Beja from Monday.
On Tuesday, these alerts will be extended to Bragança and Vila Real, coming into force in the remaining mainland districts from Wednesday.
This weather pattern is, however, expected to be revised.
Because of the "long duration of this hot spell", IPMA warns, "it is very likely that the alert level will be raised in several districts in the updates over the coming days".
