Learn Finnish: Tutkijat sanovat, että äärisää on pahempi kuin mikään aiemmin. - Researchers say that the extreme weather is worse than anything earlier.

This is a special rule for comparisons. While mikään usually means 'nothing' in negative sentences, in affirmative comparisons with kuin (than), it translates to 'anything'. It emphasizes that the extreme weather is worse than absolutely anything else.

Why is it mikään (nominative) and not mitään (partitive)?

In comparisons using kuin, the thing being compared to matches the case of the original subject. Since the subject äärisää is in the nominative case, mikään must also be in the nominative case.

I know huonompi means 'worse'. Why does this sentence use pahempi instead?

Both come from adjectives meaning 'bad' (huono and paha), but they are used slightly differently. huonompi usually implies poorer quality or lower skill, whereas pahempi implies something more severe, damaging, or serious. For extreme weather or a crisis, pahempi is the natural choice.

What kind of word is äärisää?