IEM Daily Feature
Friday, 14 November 2008

When does it rain?

Posted: 14 Nov 2008 06:20 AM

The featured chart shows the hourly frequency of rainfall observations based on observations from the Des Moines Airport since 1973. The units of this chart are average number of hourly observations per month per year for that hour. Confused? For example, the red square represents a number around 4. This means that during the month of May, approximately 4 days during May have rainfall reported during the 7 oclock hour, which is the rainiest time of the year. According to this plot, the driest time is roughly 5 PM in August. There are many other interesting things in this plot. Compare October and November versus July and August. During the summer, rainfall comes during the nighttime. During the fall, it mostly comes during the afternoon.

Good = 42
Bad = 24

Tags:   climate   precip