Could you help me with this sentence?

Largely this is OK.

I wouldn't use "after all" there though. I might say "In the end, it didn't rain".

A very tiny comment: you need a space before the opening bracket.

Here's another version, in case you're interested.

The weatherman predicted rain, so when I left the house I took an umbrella, just in case, but it didn’t rain after all.

CJ

Thank you very much. I see, you would use "in the end."
Thank you very much for your advice and comment I'll make sure that

Thank you very much for another sample answer, CJ:)

Sorry, I forgot to login when I sent a message just now!! Do you think the following sentence is way too long?

The weather forecast said that it was going to to rain, so when I left my house, I took an umbrella with me, but it didn't rain after all.

Sorry again. I've just come up with a better idea, I think.

The weather forecast said that it was going to rain. So I took an umbrella with me when I left my house, but it didn't rain after all.

I wonder this one is much better the other.

teacherJapanI wonder if this one is much better the other.

Not really. They are all quite acceptable, and it's not worth quibbling over such small differences.

OK! I try not to dwell on such minor details too much
Missing "if" is more serious than such minor details!!
Thank you very

teacherJapanMissing "if" is more serious

Yes. You need an indirect question after "wonder".

wonder if / wonder how / wonder what / wonder who / wonder where / wonder when / etc.

CJ

Thank you for your detailed instruction:) I try to be careful