Hello JT_83,
It looks like you joined the Apple Support Communities from an excellent resources; If the Apple Watch Weather complication isn't working - Apple Support.
Did you have a chance to follow all the steps offered on that page? If not, complete those steps, as they are the best steps to follow for the problem that you're experiencing. If you have completed the steps and still have a problem, make sure that both the iPhone and Apple Watch are updated to their most current versions. For help with updating the software for each device, look here:
Then, test the Weather complication again to see if this resolves the issue. If not, you may want to reach out to Apple Support directly. You can reach out to them by clicking here: Get Support or over the phone by calling the number that is most local to your region: Contact Apple for support and service - Apple Support.
We hope this information helps you out.
Kind regards!