Dear Tom,
At what time does the actual high noon time occur in Chicago?

Mark Johnson, Chicago

Dear Mark,

High noon or solar noon refers to the time of day when the sun reaches it’s highest point in the sky. During the year this high point varies at Chicago’s latitude from a maximum elevation above the horizon of 71.6 degrees on the summer solstice to its lowest value of lowest of 24.7 degrees on the winter solstice. According to Chicago astronomer Dan Joyce, this change during the year spans about 47 degrees, twice the Earth’s tilt. Joyce noted that this would be true at any point on Earth. Joyce also told us that time of high noon also varies during the course of a year from as early as 11:34 CST (12:34 CDT) in late October to as late as 12:05 pm CST (1:05 pm CDT) in mid-February.