Late August is historically one of the more unpredictable stretches of weather Iowa sees all year. Derecho season runs from May through August, and central Iowa still remembers August 10, 2020, when a derecho moved through Ames, Des Moines, and Marshalltown with wind gusts near 120 miles an hour, the kind of event meteorologists call roughly a once in a decade occurrence for this region.
Most years do not bring anything close to that scale, but Iowa still averages a derecho every year or two, and August itself tends to be one of the more active months for severe wind and hail reports across the state. If you have patio shades or motorized shades installed, this is a good week to think through how they hold up when the sky turns green.
Why late summer is Iowa's most active storm stretch
Derechos, the long lived, fast moving bands of thunderstorms capable of winds over 58 miles an hour, are officially a May through August phenomenon here, which puts us right in the tail end of the highest risk window as summer winds down. Iowa sees one on average every year or two, and while most are nowhere near the scale of the August 2020 event, even a routine severe thunderstorm line can produce straight line winds strong enough to damage anything left extended outside.
Central Iowa also tends to log a meaningful number of severe weather days through August specifically, not just isolated storms but stretches where hail, high wind, or both get reported across several counties in a single day. None of this means panic every time clouds build up, but it does mean patio shades and exterior mounted equipment deserve a plan, not an afterthought, this time of year.
What high winds do to patio shades
Exterior solar shades are built to handle wind better than most people assume, but every product has a limit, and that limit is almost always lower when a shade is fully extended than when it is retracted. A shade caught open in a straight line wind event acts like a sail, and the strain lands on the same brackets and hardware that hold the whole system to your house.
The most common storm damage I see on patio shades is not the fabric itself, it is bent tracks, pulled brackets, or a motor housing that took a direct hit from wind driven debris. Almost all of that is preventable simply by retracting the shade before a storm arrives rather than after it starts. If you already have motorized patio shades, that takes about ten seconds from a remote or your phone, which is a big part of why I recommend motorization for exterior shades specifically, not just for convenience on a sunny afternoon.
Protecting motorized shades during storms and power outages
Motorized shades raise a second question during storm season, what happens if the power goes out mid storm. Most of the motorized systems I install run on a rechargeable battery inside the headrail rather than pulling power directly from your home's electrical system, so a power outage on its own usually does not strand your shades in whatever position they were in when the lights went out.
What I do recommend is getting in the habit of checking the forecast before you leave the house on a day storms are likely, and retracting exterior shades in the morning if severe weather is expected that afternoon or evening, the same way you would bring in patio furniture. For interior motorized shades, storms are far less of a concern since they are not exposed to wind, though a prolonged outage will eventually drain the battery if you are relying on scheduled automation.
What actually held up after the August 2020 derecho
I was already in this business when the August 2020 derecho tore through central Iowa, and it left a clear pattern in what survived and what did not. Retracted patio shades came through largely fine. Extended ones, along with a lot of other exterior equipment left out that day, took the brunt of it. Homes with mature trees lost far more shade coverage from broken branches and downed limbs than from anything wrong with their window treatments.
That storm was an extreme, once in a decade event, and I am not suggesting every August brings something like it. But the lesson held up in smaller storms too, in the years since. Retracted and put away beats extended and exposed, every time, regardless of how strong the actual wind ends up being.
A simple pre storm checklist
When severe weather is in the forecast for our area, here is what I tell customers with exterior shades to do. Retract any patio or exterior solar shades fully, even if the storm looks like it might miss you, since Iowa storms shift direction fast. Close blinds or shades on windows facing the direction the storm is coming from, which adds a small buffer against flying debris and glass in the rare case a window does break. And if you know a bad stretch of weather is coming for more than a day, charge or check the battery on motorized systems so retracting is not the thing that fails you right when you need it.
What to do after a bad storm
After any storm strong enough to worry about, walk your exterior shades and give the tracks and brackets a visual check before you extend anything again. Look for bent hardware, debris caught in the tracks, or a housing that took a direct hit. A shade that will not retract or extend smoothly after a storm is telling you something is bent or blocked, and running the motor against that resistance repeatedly can burn it out.
If anything looks off, or if a storm damaged your patio shades, motorized blinds, or any other window treatment, I am happy to come take a look. Request a free estimate or call (515) 850-9700, and we will figure out whether it is a quick fix or time for a replacement.
Have a question I did not cover? Call (515) 850-9700 or request your free in-home estimate and I will give you a straight answer for your exact windows.