Attendance Forecast

How to forecast class attendance by looking out your office window:

When the weather is gray and cold, it will be too miserable outside for students to want to make the trek to class and so attendance will drop off.

When the weather is gorgeous and sunny, it will be too nice outside for students to want to spend time in class and so attendance will drop off.

It's a lose/lose situation. There is simply no such thing as good weather for classes.