Simple sentence with past tense adjective

Sorry, a bit of noob confusion here.

A native speaker said this to me:

今日は日本もとても暑かったです.

This has confused me a little, because I would have said:

今日は日本もとても暑いでした.

I trust that the native speaker understands Japanese better than I do, but I'd like a bit of advice on understanding what makes the first statement more correct. As usual, thanks, I appreciate the help.

na-adjective
静かだ(casual present)
静かです(polite present)
静かだった(casual past)
静かでした(polite past)

i-adjective
高い(casual present)
高いです(polite present)
高かった(casual past)
高かったです(polite past)


暑い is an i-adjective.;-)

Excellent, thanks again.