Crystal Lake Community Consolidated School District 47 Snow Day Predictor

About 29.1 inches a winter at a NOAA weather station 3.4 miles away, averaged over 8 winters. Between December 1 and March 31 that brings 2.5 weekday mornings a year with 2 inches of new snow or more, and 0.4 with 4 inches or more.

8.9 inches on November 30, 2025, the largest single day at a NOAA weather station 3.4 miles away in 8 winters. The snowiest winter was 2018 to 2019, with 46.9 inches.

It reads the National Weather Service forecast for Crystal Lake through the night and the 5 to 8 am bus run, adds winter alerts and the Winter Storm Severity Index, and measures the snow against Crystal Lake’s own big snow morning: 3.2 inches, the top tenth of snowy weekday mornings at a NOAA weather station 3.4 miles away.

Illinois requires a calendar of at least 185 days to guarantee 176 days of actual student attendance, each of at least 5 clock hours. The extra calendar days are emergency days used first; after they are gone, the State Superintendent may excuse days lost to an act of God or a hazard beyond the district's control without cutting state aid.

A district with a board adopted e-learning program, verified each year by its regional office, can use e-learning days in place of its emergency days, and they count as full attendance days; they cannot exceed the emergency days in the calendar.