Hello wsharpe,
Try force restarting both iPhones - Force restart iPhone - Apple Support.
Also be sure to always be using the latest iOS update for the best experience and results.
Furthermore Weather relies on location data, please confirm the following:
- Open Settings
- Scroll down and tap on Weather
- Tap on Location
- Make sure it's set to whatever option you prefer
- I personally recommend While Using the App or Widgets
- (Only because this is an Apple app) turn on Precise Location for better results.
I would not recommend having Precise Location on for third party apps as they will use this data to sell to marketers and advertisers.