Why is the iPhone weather app always off by about 10 degrees?

Hello DiedenJD,

Thank you for participating in the Apple Support Communities! We understand that the Weather app doesn't show the correct temperature on your iPhone.

In addition to the data provided from Location Services on your device, the Weather app provides weather for your current location via the following sources mentioned under the "Learn more about the Weather app" section here:

Feature availability and data sources in the Weather app - Apple Support

When you go directly to the source that provides weather for your location instead of using the Weather app, does the temperature show correct?

Cheers.