An online resource based on the award-winning nature guide –

Chirping Thermometers

The evenly-spaced chirping notes of the male Snowy Tree Cricket (Oecanthus fultoni) greet our ears nightly at this time of year.  Named for its pale color and tendency to be found in trees, vines and shrubs, this cricket is well known for its ability to convey the temperature to anyone who can count the number of chirps it makes in 14 seconds.  Add “40” to this number and you know how hot or cold the evening is in degrees Fahrenheit.  The relationship between the air temperature and the rate at which crickets chirp is called Dolbear’s Law.

Crickets make chirps (stridulate) by rubbing a structure on the top of one forewing wing (scraper) against wrinkles (file) on the underside of the other forewing.  To find a Snowy Tree Cricket that is stridulating, check the underside of branches and leaves.  A living thermometer awaits you there.

Naturally Curious is supported by donations. If you choose to contribute, you may go to and click on the yellow “donate” button.

4 responses

  1. Alice

    It’s great to have the window open, with the cooler nights. Because we have lots of woods around us, there are lots of different chirps & night sounds. I wish I knew what they all were. Some must be frogs, cicadas. And several coyotes The past 2 nights.

    September 7, 2020 at 8:16 am

  2. We have lots of these in the woods and Katydids! And Grey Tree frogs! Quite a Symphony all night long!

    September 7, 2020 at 5:53 pm

  3. Sigrin Newell

    Nathanial Hawthorne said, “if moonlight could be heard, it would sound like this.”


    September 14, 2020 at 9:49 am

  4. Judy Williams

    Dear Mary, my nickname is The Cricket Lady and I have even named my houseboat “The HMS Cricket Lady.” I got my nickname from a three-year old little girl who used to come over to watch the crickets I raised in terrariums! It isn’t just the Snowy Tree Cricket that is a living themometer. All crickets are also living thermometers. That you for your “Naturally Curious” snippets; I have started a file for all your wonderful notes on our incredible nature notes. Did you know that there are 28,000 species of crickets in the world but that no two have the same song?!!! Yours in the love of nature, Judy E. Williams!

    September 16, 2020 at 12:22 am

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s