Relative pronouns
Are these two sentences correct? If not, why not?
- The weather was hot except on the first day, that it was windy.
- The weather was hot except on the first day, when it was windy.
Thanks a lot!

Question

Answer

Only the second sentence is correct.

To connect the phrase 'it was windy' with the previous part of the sentence you need to refer back to 'on the first day'. This is a time period, so you need the connector 'when'.