O'Fallon Community Consolidated School District 90 Snow Day Predictor

About 12.5 inches a winter at a NOAA weather station 3.3 miles away, averaged over 10 winters. Between December 1 and March 31 that brings 0.8 weekday mornings a year with 2 inches of new snow or more, and 0.3 with 4 inches or more.

7.5 inches on January 25, 2026, the largest single day at a NOAA weather station 3.3 miles away in 10 winters. The snowiest winter was 2018 to 2019, with 21.9 inches.

It reads the National Weather Service forecast for O Fallon 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 O'Fallon 90’s own big snow morning: 2.2 inches, the top tenth of snowy weekday mornings at a NOAA weather station 3.3 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.