Nights that we call Tropical when the temperature at night is above 20°.
The Mediterranean is normal this temperature when the water is warm like now that is warmer than usual. But other problems are the cities that every year warmer. Lot of air conditioning at home, locals and vehicles, but all this warm goes outside with too much asphalt and high buildings. The temperature isn’t posible to down in short nights, because the asphalt and the buildings keep the warm of a sunny day.
The climate is getting warmer, and the cities more, it mean that warm nights now are also inland in big cities as Madrid. In the coast is more humid, but in the center of Peninsula during the day could be very warm, 35° and the minimum can’t go down to refresh a house without air conditioning.
In my village the warm nights aren’t usual, 1-2 is the normal in the last years. Warm nights in my village are when the clouds from the storms stay at night without rain, of course in very warm situation.
The Mediterranean breeze help to have lower maximum, but at night gets that is less colder that areas with less Mediterranean influence.
Castilla y Leon is the region with more contrast, could be very warm and dry, but when the sun comes down is cold. Even in areas close to the mountain could freeze in summer, microclimates of Spain with lot of mountain.