Wash the thermometer in soap and rinse with cool, clean water before and after you use it. Do not use hot water because the thermometer may break. After washing, it is best to soak the thermometer in alcohol for 20 minutes. You can use ethyl, isopropyl, or medical alcohol (ethanol).
1 In 2015, the average temperature across global land and ocean surfaces was 1.62Â°F (0.90Â°C) above the twentieth-century averageâthe hottest year in the 136-year record.  Since 1976, every year has been warrmer than the long-term average.
Below the tables there's a map that allows you to visually compare the annual average temperatures among states. State-wide averages of annual temperatures range from a high of 70.7 degrees Fahrenheit (21.5 degrees Celsius) in Florida to a low of 26.6 Â°F (-3.0 Â°C) in Alaska. For the entire United States, excluding Hawaii and Alaska, the year averages 52.7 Â°F (11.5 Â°C).