Wondering how hot it is outside? Crickets will tell you if you listen, scientists say

In many parts of the United States, cricket chirps are one of the unmistakable sounds of summer. However, scientists say a cricket’s chirp is more than just a mating call—it can also help you determine air temperature. All you have to do is pay attention.

It all started in 1897 when scientist Amos Dolbear discovered the relationship between heat and the frequency of a cricket’s chirps, according to The Old Farmer’s Almanac. In an article titled “The Cricket as a Thermometer,” Dolbear published the formula for using a cricket to determine temperature, which became known as Dolbear’s Law.

Here’s how it works: choose one cricket and count how many times it chirps in 14 seconds. Add that number to 40 and you’ll have the approximate outdoor air temperature in Fahrenheit, according to Scientific American.

For instance, if you count 20 chirps in 14 seconds, the approximate air temperature is 60 degrees.

Scientists say the crickets’ thermometer capabilities are explained by the weather’s effects on a cricket’s muscles, according to Priceonomics. Cricket chirps happen when a male cricket rubs his wings together. Lower temperatures cause the frequency of a cricket’s muscle contractions to slow, meaning a cricket will rub its wing together less, not chirping as often.

This story was originally published July 7, 2019 at 11:36 AM with the headline "Wondering how hot it is outside? Crickets will tell you if you listen, scientists say."