A summer without enough rain: Minnesota’s dry summer is adding up

Minnesota has been really, really dry this summer. And not just a little below average, or a few missed thunderstorms here and there.

Since June 1, a large part of Minnesota has been running multiple inches below normal for precipitation, and the deficit covers an enormous portion of the state.

The latest data from the Midwestern Regional Climate Center, through Aug. 17, paints a pretty remarkable picture. Across much of northern, central and southern Minnesota, precipitation since the beginning of June is running roughly 2 to 5 inches below the 1991–2020 average, with some areas more than 6 inches below normal.

And when you look at the departure from normal map, the message is hard to miss: Lots of orange and red, the colors that dominate much of the Minnesota map.

There are pockets that have done better. Northwestern and portions of southern Minnesota has some areas that are near normal or even above normal, and there have certainly been thunderstorms that have dumped significant rain in localized areas. But that’s part of the problem.

Minnesota hasn't necessarily been completely rain-free. We've had rain, but we just haven’t had enough of it. And the rainfall we've received has often been uneven. One town gets a downpour while another nearby city barely gets wet. A few inches from a thunderstorm can make the lawn look better for a few days, but it doesn't necessarily erase a precipitation deficit that has been building for over three months.

This is what a dry summer looks like

We’ve gone through the bulk of meteorological summer and our rainfall ledger is sitting firmly in the red. While some areas have seen pockets of heavy rain, much of Minnesota has remained stubbornly dry since the start of June.

This matters because summer is when vegetation is using tremendous amounts of water. Crops are pulling moisture from the soil, and lawns, trees and gardens are doing the same. Warm summer temperatures also mean more evaporation from the soils.

When rainfall consistently comes up short, that deficit can build surprisingly quickly, as we’ve seen with the recent expansion in our drought monitor. Since mid-May, drought-stricken areas have expanded dramatically across Minnesota. According to the Aug. 11 drought monitor, more than 88 percent of the state was experiencing drought or abnormal dryness, with nearly 45 percent in severe drought.

A thunderstorm here or there won’t necessarily fix that. And we’re not talking about one small pocket of dryness, we are seeing a large-scale precipitation deficit stretching across much of the state.

With soils drying out, streams running lower, lawns browning, and gardens and pastures needing help, it has felt like a summer where rain has often been something to chase.

But we're not out of time

There's an important distinction between being dry now and staying dry through the fall. Meteorological summer ends on Aug. 31, but Minnesota’s opportunity to make up the precipitation shortfall doesn’t end with August.

We still have September and we still have October. And, depending on the year, there can be meaningful precipitation well into November before the ground finally freezes. That gives us time. A lot can change between now and the ground freezing.

A wetter fall could go a long way toward turning things around. Several rounds of soaking rain in September and October could erase a significant portion of the rainfall shortfall and help replenish moisture before winter arrives.

But for now, the numbers tell the story: Minnesota has had a very dry summer.