NCDC’s Data Help Track the Emergence of Periodical Cicadas

Image of periodical cicada

Periodical cicadas are often known as “17-year locusts,” but they are not true locusts. Locusts are a type of grasshoper.

In spring 2013, the return of the 17-year cicadas will cover areas from Georgia to Connecticut, and the air will hum with their mating buzz. These bugs with their black bodies, striking red eyes, and orange wing veins have a rather unique lifespan. The periodical cicadas returning this year, known as the Magicicada Brood II, have been living   underground for the past 17 years. 

It is believed that the particular night of the periodical cicadas’ emergence depends on soil temperature. Cicada juveniles, or nymphs, emerge when the soil temperature at 8 inches in depth exceeds approximately 64°F. In order to predict the cicadas’ arrival this year, the National Public Radio’s Radiolab developed a citizen-science project, which invites the public to plant a homemade temperature sensor in the ground and report their findings.

To assist in the project, the Radiolab is also employing soil temperatures from NCDC’s U.S. Climate Reference Network (USCRN) in their endeavor. Because scientists placed USCRN instruments in pristine locations with consistent instruments and triplicate measurements, these temperatures provide baseline  observations to help identify potentially unreliable readings and create a more robust record to understand local variability. These official sensors also add additional data points for Radiolab’s map of “swarmaggedon.”

The periodical cicadas are not generally considered pests. However, their long and loud choruses accompanied with their somewhat menacing appearance threatens to crash weddings, graduations, and other outdoor activities during May and June, making predicting their emergence important to planners and to insect enthusiast that wish to see a rare natural wonder.

You can learn more about the Radiolab’s Cicada Tracker project and how you can participate at

Find out more about USCRN’s soil moisture and temperature observations in a paper recently published in the Journal of Hyrdometeorology entitled U.S. Climate Reference Network Soil Moisture and Temperature Observations.

Bell, J.E., M.A. Palecki, C.B. Baker, W.G. Collins, J.H. Lawrimore, R.D. Leeper, M.E. Hall, J. Kochendorfer, T.P. Meyers, T. Wilson, and H.J. Diamond. 2013. U.S. Climate Reference Network Soil Moisture and Temperature Observations. Journal of Hydrometeorology. doi: