Does precipitation fall more often on the weekends?

Dear Tom,
You have stated in this column that rain or snow do not happen more often on weekends than on weekdays, but I disagree. It does rain or snow more often on weekends.
— Jared Pasicovil, Chicago
Dear Jared,
You have fallen victim to the belief that precipitation falls more often on weekends, but it’s just not true. A bad experience with weekend weather can dominate our remembrance of past events. A weekend get-together buried by a fierce snowstorm, for example, will stand out in our memory more vividly than a similar event that comes off without a weather hitch.
A scan of Chicago’s precipitation records shows that measurable precipitation (0.01 inch or more) falls on either 33 or 34 percent of all days of the week: Sunday 33 percent, Monday 33 percent, Tuesday 34 percent, Wednesday 33 percent, Thursday 33 percent, Friday 34 percent, Saturday 33 percent.