At the moment, much of the U-S is suffering through triple digit temperatures. In our area, they're calling it "life-threatening heat." As you can imagine, unusually hot (or cold) weather leads to a spike in calls to telephone time and temperature lines around the country.
There are also lots of stories in the news showing bank time and temp signs all around the country. We've seen a few stories pointing out that the bank signs are showing the incorrect temperature – often 5 or 10 (or more!) degrees above the actual temperature. That's because those signs use a temperature sensor on a wire – if the sensor is not carefully installed, it will read the wrong temperature.
For example, if the cable leading to the sensor is not long enough, the folks who installed the time & temp sign may have just stuck the sensor where it was convenient for them to stick it. Near a roof, or in the direct sun could inflate the temperature reading by as much as 20 degrees.
The same problem exists for old-technology telephone time & temp systems – if the wired temperature sensor is not carefully installed – the temperature reading callers hear on the phone can be very wrong. That's one of the reasons our time & temp systems are Internet-based – there is no outside wiring and no outside temperature sensors. The temperature information callers hear is consistent and accurate.