Why have different temperatures readings for the same location at the same time

Compared to what? Are you looking at multiple apps for the same location, are you referring to some other local reporting of a temperature? Our local regional airport provides temperatures to the National Weather Service. I live about 3 miles south of the airport in town and I have an Acurite Weather station here at my home. There can be 3-5 degrees difference in temperatures. I can check the Apple Weather app and get one temperature and the Weather Channel weather app and get a different one for my city. As Jeff indicated, it depends on the reporting station being used.

If you using different apps, they will use different sources for the temperatures. I live in Clearwater Florida, about 20 miles from Tampa International Airport, about 40 miles away is National Weather Service and about 7 miles away is St Petersburg Clearwater International Airport and about 3 miles away is Clearwater airport. Each one frequently has a different temperature and yes sometimes 5 or 6 degrees difference.

In what app or service are you seeing these temperatures? If the readings are coming from two different services, then it's probable that they're just getting their information from different specific locations in the relevant area.

Can you please explain what you are seeing that is causing you to ask this question?