My thermometer is computerized so it has to be accurate. It agrees with the water in the dog's bowl. I am generally 8 degrees F colder than the official forecast for Phoenix, which is for the weather station at Sky Harbor Airport, in one of the warmest parts of our metro area. The US National Oceanic and Atmospheric Administration has a weather site at weather.gov which allows one to input a city or postal Zip code. Once that prediction page is up one may click quite precisely on one's location on a map on the right side of the page for a more accurate prediction. All the other weather sites get their information from the NOAA so why not cut out the middleman? Leo Martin Phoenix Arizona USA