It's very hot today

It's very hot today
 

I have the Rocket Spanish audio courses, and in one in the lessons they continuously say that the translation of "it's very hot today" is "hace mucha calor hoy". Is this correct? I would think it would be " hace mucho calor".

You're correct, but in some regions the noun is considered feminine. It's one of the ambiguous nouns, like sartén, azúcar and mar.

Let others chime in as to what they hear in their region.

So many people say "la calor" that the Academia has accepted "calor" as a both masculine and feminine word. I think though that for most of us it's best to say "el calor". :)

yes, in Northern and central Spain is more common el valor, in the South however, la calor is more frequent !

In Argentina -and I think in most Spanish speaking countries- "la calor" is used by uneducated people -and just a part of them- so, though accepted nowadays, it still has a vulgar nuance attached to it. For instance, in local TV a character is shown saying "la calor" -and other terms- generally as a sign of charming coarseness. I am still to hear a TV program or flick with a character saying "la calor" and another character replying "la calor" as if that use is conventional language.

Thank you all, this is very interesting.