。
The weather's worse than I expected.
Literal
Predicted-more-than bad weather is-[plain-だ].
Note 天候 ('weather conditions, climate') is more formal/written than the everyday 天気; 悪い ('bad') paired with the past-tense relative clause 予想したより ('more than I predicted') gives the sentence a measured, written feel even with the plain copula だ. Useful as a register cue: a swap from 天気 to 天候 alone shifts the whole tone.