Abstract: Solar eclipses produce a wealth of easily-observable and quantifiable changes in the environment including changing animal responses, light intensity, and— of interest here— air temperature. It is well-known that the air temperature drops as sunlight diminishes during a solar eclipse due to the decrease in solar radiation per unit area; this change in temperature generally reaches a minimum value around the point of maximum eclipse, before rebounding and warming again as sunlight returns and incoming solar radiation increases.
To quantify this solar radiation induced temperature decrease and subsequent rebound, the authors conducted experiments meant to catalogue temperature changes during both the August 21, 2017 and April 8, 2024 total solar eclipses. Temperature data was collected at set intervals using a Hobo data logger hung from a tripod in the open air, with experiments conducted along the eclipse centerlines at Jay Em, Wyoming, USA in 2017, and Carbondale, Illinois, USA in 2024. During the 2017 eclipse, the air temperature in Jay Em decreased approximately 5 °C over the course of 80 minutes, from 27.4 °C at first contact to 23.0 °C at second contact. Conversely, during the deeper 2024 eclipse, the air temperature in Carbondale dropped ~14 °C over the course of 75 minutes, from 33.5 °C at first contact to 20.9 °C at second contact. In both cases, the air temperature rose again following third contact.
Taken as a whole, these data quantify the temperature differential seen during various eclipse phases, prove that this drop in temperature is both a repeated and observable phenomenon regardless of time of year or location, and concur with both the literature and modern physics as they relate to the incoming solar radiation budget, eclipse duration, and associated atmospheric dynamics.
