Cricket Chirp Thermometer Calculator

Count chirps for 1 minute, or count for 14 seconds and multiply by 4.
Biology

Use Dolbear's Law to estimate outdoor temperature from the number of cricket chirps per minute.

Formula

T(°F) = 50 + (chirps/min − 40) ÷ 4
  • Dolbear's Law (1897) correlates snowy tree cricket chirp rate with air temperature.
  • Valid approximately between 55°F and 100°F.
  • Works best with snowy tree crickets (Oecanthus fultoni); other species have different rates.

120 chirps per minute

Inputs
  • Chirps per Minute: 120

T = 50 + (120 − 40) / 4 = 50 + 20 = 70°F (21.1°C).

Frequently asked questions

Which cricket species does this apply to?
Primarily snowy tree crickets. Field crickets follow a slightly different formula.
How do I count chirps?
Count for exactly 14 seconds and add 40 to get the Fahrenheit temperature directly.