Only Bragança, Vila Real and Viseu are not included.

A yellow warning, the third most serious in a series of four, is issued when there are risks for some kinds of activities.

On Saturday, Lisbon is expected to reach 33ºC, Porto 30ºC but Evora and Beja may hit 37ºC.

Sunday is expected to be even hotter with 37ºC in Lisbon, 32ºC in Porto and Faro and 39ºC in Santarem and Evora.