A thermal low (or heat low) is a low-pressure centre formed by intense ground heating, especially in summer over continental surfaces. Heated air rises, reducing surface pressure without generating fronts or significant precipitation.
On the Iberian Peninsula
In Spain, the Iberian thermal low is a frequent summer phenomenon: heating of the Central Plateau generates a low that draws in sea breezes, the Atlantic nortada, and south-easterly winds over the Mediterranean. This thermal low interacts with trade winds in the Canary Islands and local breezes, modulating summer weather across the Peninsula.