Why Are There So Many Wild Mushrooms This Fall In Duluth & Superior?

The other day I was in the backyard and noticed what looked like several softballs in the grass. I thought it was strange, as we don't have any softballs. So I went over to pick them up and noticed that they were just large, softball sized white mushrooms. These things were huge! I've never seen them that big in my yard before. I took a closer look at the rest of my yard, and it looks like old school NES Super Mario Brothers out there with mushrooms all over the place. A lot of them are huge! Why are they so big this year?

I figured it had to be something weather related so I contacted my weather buddy, Brandon Weathers at WDIO. Yes, his actual last name is Weathers. He was born to do this. Anyway, I asked him if there is a meteorological reason that we have so many mushrooms. He has a pretty good hypothesis that I'm going to go ahead and say is probably 100% accurate.

Brandon's hypothesis is that we've had a really warm and humid end of summer and fall season. He elaborates,

We’ve heard by now that this summer (June, July, August) was the warmest on record for Duluth. That wasn’t only because of consistently warm daytime highs, but also consistently mild nights. Temperatures can only drop as low as the dew points, so inevitably a stretch of warmer than normal low temps also implies high moisture content and humidity.

That weather pattern didn't just apply to the warm summer we had. Brandon explains that even from September into October we were unseasonably warm.

September was yet another warm month with the mean temperature a full three degrees above normal. Then there’s this first week of October, which has been very mild. The first 7 nights of the month have been 10-20 degrees warmer than normal consistently. In fact, it’s the unseasonable warmth and moisture that’s also responsible for all of the pesky fog we’ve seen lately!

So basically, this stretch of weather and unseasonable warm and moist fall is the perfect petri dish for these mushrooms to thrive.

Get our free mobile app

Some mushrooms are edible, but you really need to know what you're doing if you ever think about using these. Make sure to use caution and read up more about training opportunities. There are poisonous mushrooms in Minnesota & Wisconsin, so beware.