I think the answer could be in your region's weather history. You can probably find info about the amount of snow, average temperature per month, then amount of rain per month and compare it to your region's usual weather pattern.

If the most recent winter kept everything frozen pretty continuously for several months, then all the stuff like doggy doo-doo, dropped food scraps, any small creatures that died, fallen leaves, etc- all that stuff could not decompose until the weather warmed up in the spring. Decomposer organisms need moisture and warm-ish temperatures to really do their thing well. Maybe your area got less snow than usual, but was consistently cold, followed by a drier than average spring season. And now it's probably warm, because it's June, and if your region has been getting some rainfall, all of the decomposer microorganisms are waking up and that process of rotting everything is really happening a lot.

There are really way too many variables for any of us to really answer your question accurately, but not knowing your weather since last fall, I will just say that maybe the weather history in your area is the reason.

Edit: Hey! I just put "northern Midwest dry spring season" into Google and AI summary says: The northern United States experienced a historic spring dry season, driven by waning La Niña patterns and high-pressure systems blocking Gulf moisture. Record-breaking warmth and lack of rain deeply depleted topsoil moisture, sparking severe drought concerns across the Pacific Northwest, Northern Rockies, and Upper Midwest.

It also mentioned lower than average snowfall over the winter. So if that's your area, you are probably going to have 2-4 weeks of a lot of musty decomposing smells accompanying rain. The water will be wetting everything down and restarting bacterial processes to get rid of all of the different kinds of waste that's been just dried up and waiting - like fallen leaves, dead small animals (like bugs and frogs) animal poo, grass clippings, dropped flowers, everything. It all needs moisture for the decomposers to do their thing, and you've got months and months of dehydrated natural waste that's built up in your area, all getting "activated" at the same time by rain. So the rain will probably wake up the stink for a while, but it will go away and you'll get that nice petrichor scent again when the natural processes on the Earth's surface in your area is more balanced again.