Dolbear’s Law

Today, dear hearts, let’s dabble in Dolbear’s Law.


I Vespri Siciliani by Domenico Morelli (1823-1901) via Wikimedia Commons

Oh, no—don’t run off!

Dolbear’s Law is neither as lofty nor as boring as you might think (c’mon, now, you know me better than that).

Forget gavels, girls, and take the hint:


Image courtesy of Walt Disney Productions for RKO Radio Pictures via Wikimedia Commons

Mind you, the clue is not so much “Jiminy” as “cricket.”

That’s right—Dolbear’s Law concerns crickets. More specifically, it reveals the relationship between air temperature and the rate at which crickets chirp.

It’s true. When crickets are singing in the evenings from spring through fall, you can actually figure out the temperature outdoors by counting chirps. Here’s how, according to The Old Farmers Almanac:

Count the number of chirps in 14 seconds, and then add 40 to find the temperature in Fahrenheit.

For example: 30 chirps + 40 = 70°F

It works for Celsius, too, in case you were wondering. Metric mavens can count the number of chirps in 25 seconds, divide by 3, then add 4.

The cricket sound clip below plays for only a few seconds, but you can play with it to get an approximation:

As far-fetched as it sounds, this is an actual scientific fact proven by 19th-century physicist Amos Dolbear. At the time, he mistakenly believed that the number of cricket chirps determined the temperature, but he did come up with a factual formula. How he noticed or even thought to test his theory we may never know, but he published his findings in an article called “The Cricket as a Thermometer” in an 1897 issue of The American Naturalist.

And, as if THAT cricket fact isn’t mind-tickling enough, there is a rumor floating about that says a slowed recording of cricket chirps sounds like a human chorus. Listen:

Lovely, but can it be true? Read more about the mysterious music on



  1. Winnie Nielsen says:

    Wifi just tossed out my comment. I am fascinated at how there is a synergy between this insect and the atmosphere conditions allowing a predictability of something as sensitive as temperature. Absolutely fascinating!

  2. Wowie Zowie ! I always loved cricket sounds ( got one in my basement now been singing alot) but this is so amazing. I did know the cricket chirp counting thing, we learned it in 3rd grade ( don’t they teach kids anything cool anymore? ) but the “choral music” thing is so supernatural and spiritual. Just a great way to start the day ! Our crickets are slowing down and first frost will put an end to their music.

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