Dear Tom,
A recent column stated that two of Chicago’s all-time highest temperatures of 104 degrees occurred on June 20. Did they actually occur in astronomical spring?
Thanks, Larry M., Mt. Prospect
Dear Larry,
They did, but just barely. The June 20 record high temperature of 104 degrees occurred twice, first in 1953 and again in 1988. In 1953 the summer solstice, the start of astronomical summer, did not occur until noon on June 21, nearly a day later. In 1988, the solstice was on June 20, but not until 10:56 p.m., approximately 8 hours after the record high was reached. Meteorologists like to define the each of the four seasons in terms of three full months with similar weather, classifying meteorological summer as June, July and August. In those terms, 61 of 65 Chicago’s 100-degree days have occurred in meteorological summer with the remaining four in September’s opening week.
