OTTUMWA — Rain is one thing. This is ridiculous.
Five out of the past six weekends have seen Ottumwa soaked by heavy rain. In fact, 71 percent of all the rain that has fallen on the area since June 7 has fallen on the weekends.
Starting in June, Ottumwa’s weather has fallen into a predictable pattern of heavy rain over the weekend, followed by a few comparatively dry days. But about the time the grass dries out enough to mow the lawn again, the rain returns.
Need proof? Here are the weekend rain totals beginning with June 7-8:
June 7-8 — 0.95 inches
June 14-15 — Trace precipitation
June 21-22 — 1.50 inches
June 28-29 — 1.16 inches
July 5-6 — 1.72 inches
July 12-13 — 1.19 inches
In the period from June 7 to July 13, there were 25 weekdays and 12 weekend days. The sum of all rainfall during the week in that time came to 2.66 inches. The weekends totaled almost three times that — 6.52 inches — in half the number of days.
Mother Nature doesn’t really have it in for our outdoor plans though, right? Not according to Rob DeRoy, the data manager at the Des Moines National Weather Service office.
“That’s just the timing of the systems,” he said.
The average rainfall at this time of year runs at about 0.15 inches per day. But that’s not the way weather works. Fronts move through bringing rain at different intervals, with dry periods in between.
“The averages are based on day-by-day precipitation,” DeRoy said. But since nature doesn’t work on a specific schedule rain, “is going to occur over shorter periods. It’s going to be one day, three days, five days.”
So what we’re seeing right now is just a statistical fluke.
And it may be changing. This week is expected to be cool and dry. There’s a chance the overnight lows could set records, but it’s not guaranteed.
The next chance of rain? On Sunday, of course.