It should be hace mucho calor, meaning it is very hot (weather)
"Mucho" or "mucha."Mucho
mucho/mucha
very very hot
Demasiado, excesivo, tanto, tan, tanta, mucho, mucha
The Spanish word "mucho" means many, or a lot. (the forms are mucho, mucha, muchos, and muchas)
Demasiado, excesivo, tanto, tan, tanta, mucho, mucha
mucho (or depending on the noun: mucha, muchos, or muchas).
Translation: There's a lot of heat today. (It's hot today)
Hace mucho calor en otoño.
Va a hacer mucho calor.
As a stand-alone statement "¡Que calor!"is a complaint about the heat related to weather. Similar English statements would be "What heat!" or "How hot!". A closer translation to the sentiment is "Oh, the heat!" Literally It means "that heat"