Learn French: Par rapport à hier, il fait plus chaud. - Compared to yesterday, it is warmer.

Both mean 'compared to', but par rapport à is a very natural and frequently used expression in everyday French. It is broadly used to compare situations, draw contrasts, or say 'in relation to'.

Why does the sentence use il fait instead of il est for 'it is'?

As a quick refresher, French uses the verb faire (to do/make) rather than être (to be) when talking about the general weather or outdoor temperature. We say il fait chaud (literally 'it makes warm') for 'it is warm'.

Since this is a comparison, why isn't there a que (than) in the sentence?

Normally, you use que when the second part of the comparison directly follows the adjective, like in Il fait plus chaud qu'hier (It is warmer than yesterday). Because this sentence already establishes the baseline of the comparison at the very beginning with par rapport à hier, a que isn't needed.

Do you pronounce the 's' in plus chaud?

No, the 's' is silent here. When plus (more) comes right before an adjective starting with a consonant, you don't pronounce the 's'. You generally only pronounce it if the next word starts with a vowel sound.