Bigger rains are more common in the warm season
As we shared yesterday, rainfall over the past several weeks has been running behind average. Assuming we don’t enter a continuing dry spell, this is the time of year when those deficits can be erased with a few well-placed rains.
For rainfall of at least an inch in a day, the average jumps from about every other year in April to one day each May. While that may not seem like a big change, consider it this way: we’re twice as likely to have a one-inch rain in May than we are in April!
May has been trending wetter over the past couple of decades. The long-term average rainfall over Iowa is 4.18”, but the 30-year average that moves annually rose from 4.24” in 2000 to 4.70” in 2019. One of the effects of climate change in the Midwest is an increase in heavy rainfall, and this is one sign of that trend.