Order for spanish adjectives

[senior wags]

When I translate "Today is a hot summer day", it translates to "Hoy es un día de verano caliente". How do I know which order to place the adjectives after 'un dia'? Would it be wrong to say "Hoy es un día caliente de verano"

[AngelicaDeAlquezar]

Both sentences are valid.

Some people might prefer to keep the words "día de verano" together, so they'd say "un día de verano caluroso/cálido" or "un caluroso/cálido día de verano".
Some others would take "caluroso" as referring to "verano" when saying "un día de verano cálido/caluroso", but the context would make clear your meaning, so the adjective can be placed almost everywhere without altering the sentence or the grammar.

*Note: I changed "caliente" to "cálido" or "caluroso", because these two words are the ones that we associate the most with weather.

You may find some useful discussions about this topic here and here.