The start of July will bring a prolonged heatwave to mainland Portugal, with tropical nights and temperatures soaring to 43°C in some regions of the country. ADVERTISEMENT ADVERTISEMENT According to the Portuguese Institute for Sea and Atmosphere (IPMA), 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,