If you’re not sure what the temperature is on hot summer day, just listen to the crickets. According to the Library of Congress, the musical creatures adjust their signature sounds according to the temperature, which means that if you count how many times a cricket chirps in 25 seconds, divide by 3, then add 4 to get the temperature.
Example: 48 chirps /(divided by) 3 + 4 = 20° C
