SIRI and Dewpoint
When I asked Siri, what the dewpoint is right now, she responds with websites that define dewpoint.
iPhone 14 Pro, iOS 17
So it does; interesting discovery. Sounds like something that should be fixed; the best place to suggest something to Apple is here→Product Feedback - Apple
This is a user-to-user forum, with minimal Apple participation.
If I ask for the humidity it gets that correct, and if I open the weather app it displays the humidity and dew point, so the information is there on the iPhone.