I remember my first Heritage Days in 2015 quite well. I had my first experience putting up the fabled tents, absorbing the wisdom of the legendary Marty Mulford who had served as “tent foreman” for decades at that point. “We gotta move that thing about 2” to the right,” he said, and we all gamely dragged the 30’x30’ canvass two inches to the right.
“Don’t pull to tight on that yet or it might… Yep, that might happen,” he said as I snapped a guy line trying to apply tension. “You don’t wanna fall on one of those stakes,” he warned.
A lot of his direction only made sense after the whole fiasco was done, and I could see why he had such particularities in the tent locations and order of operations. Can’t go here, we’ll hit a tree root – learned that back in ’91. Don’t put this post in before that one or you’ll have a heck of a time getting the roof taught.
After we’d gotten the tents upright, we all reconvened in the break room for coffee and cookies before heading back out to finish setting up. Marty regaled us with stories of good tent years and bad, years where driving sleet and snow made for a miserable experience and years where warm weather made the bugs as numerous as the sleet pellets from a year before.
Most years, you can get by with a pretty lackluster tent job – but you don’t know until the weekend is over. Some years, high winds will quickly reveal who got lazy driving in stakes, or heavy rains will make it clear why we needed to get the seemingly-minor sag out of a corner.
2024 was my 9th year participating in Heritage Days, and every year folks come up to the information booth and comment in true midwestern fashion how “we got such great weather this year.”With next year coming up on our 50th Heritage Days, I got to wondering: what is the usual weather on Heritage Days weekend?
Fortunately, Weather Underground keeps a database of historical weather observations, so I took a little time to dig in. I wanted to see how, if at all, the weather on that second full weekend of October has changed since the first Heritage Days in 1975. It’s important, here in the midst of the Anthropocene, to check the data against our perceptions at least occasionally.
I’ve been uneasy this fall about the weather for a variety of reasons. It was 81°f on October 21st. We’re in a burn ban and haven’t gotten significant precipitation for what feels like an eternity (though that might have changed by the time this post drops). I seem to remember the end of cross country season being cold when I was competing in the mid aughts. Is it just my imagination? Selective memory? Or have I really noticed a perceptible change in my lifetime in the weather in Autumn here in Iowa?
Realistically, selective memory probably plays a huge role. I remember the cold, wet race days because a) they stick out and b) those tended to be my best days as cold weather for me is like spinach for Popeye. But at least in part, the data agrees with my observations.
Looking through the last 49 years, we see a clear trend upwards in the high temperatures. It's important to remember too that the Saturday of Heritage Days can fall as early as October 7th, or as late as the 14th, so that confounds the picture a bit, but probably not much climatically.
One also must remember that I have chosen here a snapshot of a single day, in a single location. We must use caution making assertions about the global phenomenon of a changing climate using such a small data set. While almost 50 years feels like a robust sample, climate scientists use a minimum of 30 years to determine “climate normal,” the baseline against which a given day is measured.
The picture might change substantially when compared against 60 or 100 years. This gives climate denialists plenty of ammunition; they can take a snapshot of 10 or 15 “stable” years to suggest that changes are minute, or even nonexistent, and a graph can offer a compelling piece of evidence to the layperson.
The subtle change in temperatures I can observe with this set of data also leaves out myriad other variables that play into a “nice” day. Wind, humidity, and precipitation lay beyond my motivations for this simple assignment, but maybe some yucky day this winter I’ll get bored enough to dig in.
I was also fascinated to see that just ever so slightly, the daily lows have gone down on average over the past 50 years. That’s distinctly at odds with observations throughout the region noting nighttime lows rising faster than daytime highs, and winter temps rising much faster than summers as the greenhouse effect hampers Earth’s ability to dissipate heat after sunset.
But again, small sample size: just a few extreme dips could drag the overall average down dramatically with so few points of measurement. And that’s what sticks out to me most when I look at the graph: the change in “wiggliness.” The hottest-ever and the coldest-ever have both occurred in the last 15 years, with the change from one year to the next becoming increasingly dramatic.
Thinking back to your high school math classes, you probably learned about mean and standard deviation: “mean” is the average number in a given set, while deviation is the amount by which a number within that set differs from the mean. So a set of 5, 6, and 7 would have an average 6 and a standard deviation of ~0.8. A set of 4, 6, and 8 would also have an average of 6, but a standard deviation of ~1.6
This is what climate scientists mean when they refer to a greater likelihood of “extremes” taking place as our climate changes. The averages might not move much, but the amplitude has changed considerably even in just this tiny snapshot of one locale in Northeast Iowa. The picture becomes even more striking when we zoom out.
I think about Hurricane Helene, and before that Hurricane Maria in Puerto Rico and Hurricane Harvey in Houston – three once-in-a-lifetime storms that have landed in just the last 6 years.
I think about the last two springs here on the Upper Mississippi, when floodwaters have crested to near-record levels only to be followed by unusually low waters by late summer. The overall average river level might not look that different if I plotted it out day by day, but the standard deviation would tell a different story.
I think about the “polar vortex,” an always-present component of the global weather system that has come to colloquially describe especially brutal cold snaps in the winter. I have noticed in the last few years, as they’ve grown more common, people remember those winters as "pretty rough," even though each January and February has, on average, been warmer than the last going on five years now.
That selective memory, and the generally short memory of most humans, make it difficult to notice real climate change happening before our eyes. But the numbers don’t lie. Our climate has changed, significantly, in our lifetimes, and likely will continue to do so. We can adjust, we always have, but we must acknowledge the data staring us in the face.
Looking Back
Heritage Days dominated the better part of early October, but we also had a slew of new and exciting events taking place this past month. Music under the Moon, a partnership with Cabin Concerts, was a huge success! Many thanks to the musicians, organizers, and attendees who brought the sleepy old ghost town of Motor to life for a magical evening.
We also welcomed the entire fifth grade class from Central to their first School of the Wild down at Motor Mill. With fantastic weather and inquisitive minds, it was an unforgettable week for everyone involved.
The O.W.L.S. took a trip up to the Iowa Dairy Center south of Calmar for a look at the past and future of dairy production, including a guided tour of the dairy museum and the state-of-the-art robotic milking facilities.
Lastly, on October 26th runners toed the line for the Pony Hollow Trail 5k/15k. Lots of smiling faces at the finish line on such a beautiful fall day. Thanks to all who came out! Results can be found here.
Looking Forward
On November 21st at 11:00 AM we will welcome Tom Milligan to the Osborne Nature Center for his unique one-act play "American Dreamer: The Life and Times of Henry A. Wallace" which brings to life the legendary Iowan who pioneered agricultural science before serving as U.S. Secretary of Agriculture and Vice President under Franklin Roosevelt.
That Saturday, November 23rd, the holiday lights will once again flicker on at Motor Mill, with an Open House to boot. If you haven't seen the new inn and stable renovation, this is your chance! Festivities begin at 4:00 PM.
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