The State Meteorological Agency, Aemet is predicting highs of 36 degrees in Majorca on Friday and over on the Peninsula, an orange warning is in place for temperatures of 40 degrees in Córdoba and Jaén and 39 in Seville with overnight lows of 26 degrees.
Stormy weather is forecast in Galicia, Asturias and Castilla y León with the possibility of hailstorms in mountainous areas.
It will be hot and sunny and 38 degrees in Extremadura, and slightly cooler in areas west of there.
Overnight temperatures will hover around 22-25 degrees in central and southern areas of the Peninsula.
On Wednesday, a trough of low pressure with cold air in the upper layers of the atmosphere and heat on the surface will cause heavy rain, thunderstorms and strong winds in some areas of the Peninsula, particularly in Galicia, Cantabrian communities, the north and east of Castilla y León, Navarra, La Rioja, Aragon, Catalonia and in northern areas of the Valencian Community.
On Thursday, more stormy weather will batter north and central areas of the Peninsula, with 15-20 litres per square meter of rainfall an hour expected.
Castilla y León, Cantabrian communities, Navarre, La Rioja, Aragon and northern Catalonia will bear the brunt of the stormy weather.
Temperatures will drop in western areas of the Peninsula and rise in eastern areas and the Balearic Islands on Thursday. Highs of more than 36 degrees are forecast in the Ebro and Guadalquivir valleys and 35 degrees in central areas, the southern plateau, Valencia, Murcia and Majorca.
It will be very hot from early in the day on Thursday and Friday and they're unlikely to dip below 20 degrees overnight in the Ebro Basin, coastal areas of the Mediterranean and central and southern areas of the Peninsula.
From Friday onwards there will be showers and storms in Galicia, Cantabrian communities and the Pyrenees that might extend throughout northern areas .
Temperatures in the Ebro Valley will continue to hover around 36 degrees, but they’ll drop slightly in central and southern regions and along the Mediterranean coast.
Majorca will have highs of 34-36 degrees.
Over the weekend, the mercury will rise yet again and the heatwave is expected to last until Tuesday or Wednesday, but there will be some showers in Galicia, coastal areas of Cantabrian and the Pyrenees.
It will be hot and sunny and 36 degrees in Valencia, the Ebro Valley and central and southern areas of the Peninsula with highs of 40 degrees in the Guadalquivir, Tagus and Guadiana valleys.
Trade winds are forecast over the next few days in the Canary Islands, with clouds in mountainous areas and temperatures typical for this time of year.