How are temperatures measured for geographic areas?


With all the news about record temperatures in various places in the US, how are they being measured? I assume they are as simple as placing a thermometer in direct sun or under shade and calling it a day. Please provide me ammo to help me settle this debate with my wife. Thank you.

In: 3

The NOAA operates hundreds of weather stations around the country. In general they try to NOT mount them in direct sunlight OR very dark shade. There’s a lot of guidelines they have for where they install them, because they’re trying to account for that shaded or completely in-the-sun stations will read differently.

So when reporting conditions for an area, you get a few different things.

In my area, a lot of times the weather will say, “It’s 103 at <local landmark>.” There’s a weather station installed there, we all know where it is, so hearing the temperature there helps a lot of people understand what their conditions are. However, the city itself has a big radius, maybe 20 miles. So someone in the far north portion might have very different weather from that weather station. The news doesn’t report any northern landmarks, but if we see a map with lots of different temperatures on it that’ll be obvious.

Sometimes it’s fudged. Maybe there’s a weather station very south and very north and they have wildly different numbers. If the temperature for somewhere *between* them is being reported, someone’s probably done math and assumed the temperature is somewhere between the two. But ideally, you’re only seeing the numbers from actual weather stations displayed near that weather station and the news lets *you* use your imagination to figure out the in-betweens.

You can kind of see it in action at the site “Weather Underground”. That site lets people install their own weather stations that report to the site. A lot of times you can pick out which people didn’t follow the instructions well and have a station in the sun because they’ll be way off the other stations in their area.