Here is the Clear Sky Clock for the James C. Veen Observatory. With this, you can determine the chance of cloudy or clear conditions for observing.

And here is the Clear Sky Clock for Grand Rapids.

At a glance, it shows when it will be cloudy or clear for up to the next two days. It's a prediction of when the Observatory and/or Grand Rapids will have good weather for astronomical observing. By clicking on these charts, it will take you to a separate site with more detailed information.

Thanks to Atilla Danko for generating the clocks.