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.
Last year was the thirty-seventh consecutive year of above-normal global temperature. According to data from NASA, the global temperature in 2013 averaged 58.3 degrees Fahrenheit (14.6 degrees Celsius), roughly a degree warmer than the twentieth-century average. Since the dawn of agriculture 11,000 years ago, civilization has enjoyed a relatively stable climate.