The institute forecasts strong winds with gusts of up to 75 kilometres per hour (km) for these two mainland districts.

The yellow warning is the least severe on a scale of three and is issued whenever there is a risk for certain activities dependent on the weather.

IPMA forecasts mostly clear or sunny skies on the mainland on 16 September, strong winds on the west coast and highlands, and a drop in maximum temperatures in the north, central interior, and south.

Minimum temperatures will range between 12 degrees Celsius (Guarda) and 20 (Faro), and maximum temperatures between 23 degrees (Aveiro) and 32 degrees (Évora).