ERA5 climate data · Broken Arrow
Downpours in Broken Arrow are up 21% since the 1990s, and the drainage was built for the old rainfall
We counted every day with an inch or more of rain in Broken Arrow from 1995 to 2024. The heavy days, the ones that overwhelm drainage and drive water against the foundation and under the slab, are climbing.
Broken Arrow went from 8.9 to 10.7 heavy-rain days a year.
That is a 21% rise in the downpour days that overwhelm drainage, over three decades.
What this means if you own a home in Broken Arrow
Every part of a home's water defense, the grade of the yard, the gutters and downspouts, and the drainage around the slab, was sized for the rainfall of the era the house went up. In Broken Arrow, that era was drier. Now the downpour days those systems have to handle come 21% more often, so the water they used to shrug off is the water that now ends up against the foundation and under the slab.
You cannot change the weather, but you can resize the defenses to today's rainfall: extend the downspouts and regrade so water runs away from the slab, add French drains and area drains to carry it off, and seal the cracks already letting water into the foundation. The homes that stay dry are the ones whose drainage matched the rain that is actually falling now.
Where this comes from
Source is ERA5 reanalysis via the Open-Meteo archive: daily precipitation for Broken Arrow from 1995 to 2024. A heavy-rain day is any day with 25.4mm (1 inch) or more. We compared the average annual count in the recent half of the record against the early half. Broken Arrow also averages 2.2 days a year now with 2 inches or more, the ones that do the real damage.
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Broken Arrow rainfall and your home: FAQ
Is it raining harder in Broken Arrow than it used to?+
Yes, in the way that matters for a home. Broken Arrow now averages 10.7 days a year with an inch or more of rain, up from 8.9 in the late 1990s, a 21% increase over 1995 to 2024. It is the heavy days, the ones that overwhelm drainage, that have climbed.
Why does that matter for my foundation in Broken Arrow?+
The grade of the yard, the gutters and downspouts, and the drainage around the slab were all sized for the rainfall of the era the house was built in. When the number of downpour days rises, that older drainage gets overwhelmed more often, and water that used to run off ends up against the foundation and under the slab.
What can I do about heavier rain in Broken Arrow?+
You cannot change the weather, but you can resize the defenses: extend the downspouts and regrade so water runs away from the slab, add French drains and area drains to carry it off, and seal the cracks already letting water into the foundation. The point is to match today's rainfall, not the 1990s.