How many times does a cricket chirp in fifteen seconds?

The chirp rate is not that fast, no more than about 3 per second in hot weather.

It is usually measured in chirps per minute, and because it varies with the cricket's metabolism, it is considered a way to determine the approximate outdoor temperature. The relationship is called Dolbear's Law, for Amos Dolbear, who calculated it using the snowy tree cricket in 1897. If used for field crickets, the calculation may be off by plus or minus 2 degrees depending on the age of the cricket.

- If you count the number of chirps in 15 seconds and add 40, you have a Fahrenheit temperature.

(a variation on this is chirps in 15 seconds, and add 37)

- If you count the number of chirps in 8 seconds and add 5, you have a Celsius temperature.

e.g. at 68F/20C, the count should be about 112 chirps per minute.