Would a jacket marked ‘Dry clean only’ be hurt by wearing it in the rain?
Probably not though if it gets really wet it might need a cleaning/pressing afterwards (jacket like a coat or jacket like a blazer?). It’s not the water so much that causes a problem but the soap and high drying temperatures, I think. I was wearing a blazer marked dry clean only and got caught in the pouring rain. After it dried out it was all wrinkly but came back from the cleaners good as new. I have had lots of other clothing get wet from rain with similar results, including wool.