Freeze-Thaw in the Midwest 24 cities. 365 days. One map.
How many freeze-thaw cycles did Upper-Midwest cities actually see in 2025 — and how does it compare against the 10-year baseline? Every city’s full year is plotted directly on the map below, no clicking required.
We pulled a full year of NOAA data across 24 Upper-Midwest cities so owners can see exactly what their buildings absorbed in 2025 — and plan repairs before they become rehabilitations.
2025 vs. the 10-Year Baseline, Plotted
Each badge anchors to a NOAA station and shows the city’s 2025 freeze-thaw count alongside the deviation from its 10-year average. Orange means more freeze-thaw activity than baseline (harder on infrastructure). Blue-slate means a milder year.
Every City. Every Day. Side by Side.
Each small calendar shows all 365 days of 2025 — colored cells mark days the temperature crossed freezing (a freeze-thaw cycle). Sort the grid to surface the cities that diverged the most from their baseline.
What Every Cycle Does to Your Building
Plotting the cycles is only half the story. Each one is a physical event happening inside your concrete and masonry. Water works its way into pores, hairline cracks, and mortar joints. When it freezes it expands by roughly nine percent, prying the material apart from the inside; when it thaws, the void it leaves behind draws in even more water, ready for the next freeze. A single cycle is harmless. The fifty, sixty, or seventy that many Upper-Midwest cities logged in 2025 are not — the stress is cumulative, and a season of it is what later surfaces as scaled surfaces, spalled decks, failing joints, and corroding steel. The encouraging part is that this is one of the most predictable failure modes in commercial construction, which makes it one of the most preventable; the full chemistry of why Midwest concrete fails faster than the climate alone would suggest is laid out in our explainer. What follows is where those cycles do the most damage — and what to watch for in each.
From surface scaling to structural loss
Concrete shows the damage first and most visibly. It begins as surface scaling — a fine flaking of the top layer — and progresses to spalling, where saturated concrete freezes near the surface and breaks away in chunks. The real danger is what those open paths expose. Once water and de-icing salt reach the embedded reinforcing steel, corrosion takes over, and the expanding rust does far more structural harm than the frost ever did. Caught at the scaling stage, the work stays in the range of routine concrete repair — patching, sealing, crack injection. Left until the steel is involved, the same defect becomes full-depth structural rehabilitation at many times the cost.
The hardest-hit asset you own
No asset in a commercial portfolio absorbs more of this than an open parking structure. The decks face the sky and take every cycle directly, the de-icing salt tracked in by vehicles accelerates the corrosion chemistry, and the same water that drives the frost works down to the rebar and post-tension cables below. The result is deterioration that runs years ahead of an enclosed building. That is why we put together a practical two-tier inspection routine owners can run themselves and a field guide to why these structures fail faster here — and, when the numbers eventually force a repair-or-replace call, a straight ROI analysis to keep the decision honest.
Joints, mortar, and keeping water out
Every freeze-thaw cycle is, at its root, a water-management problem — which makes the building envelope the place to stop it before it starts. Failed sealant joints and eroded mortar are the entry points; close them, manage the drainage, and the cycles have far less to act on. The discipline is less about any single product than about keeping the whole system intact year over year, which is the logic behind a deliberate waterproofing strategy rather than a patch-as-it-leaks habit.
Plan Around the Freeze, Not After It
The takeaway from the 2025 numbers is simple: the cycles are coming regardless of what you do, but the damage they cause is a choice. The buildings that come through a Midwest winter intact are the ones that find and document problems before the cold, scope them in spring, and do the real work in the warm window — not the ones that wait for a leak. Learn to read the warning signs early with our guide to condition assessment reports, and weigh the long game against the compounding cost of deferred maintenance.
Freeze-Thaw Cycles & Your Building: Common Questions
Quick answers to the questions owners and property managers ask most about the 2025 freeze-thaw data and what it means for their buildings.
What counts as a freeze-thaw cycle in this report?
A freeze-thaw cycle (FTC) is defined here as a calendar day on which the temperature crosses 0°C in either direction. Daily readings come from NOAA’s Global Historical Climatology Network – Daily (GHCN-D) for the listed weather stations, and each city’s 2025 count is compared against a 10-year baseline (2015–2024) and a 30-year baseline (1995–2024).
How many freeze-thaw cycles did Upper-Midwest cities see in 2025?
Across the 24 cities tracked, 2025 counts ranged from 45 days in Chicago to 95 days in Sioux City, with most cities logging fifty to ninety freeze-thaw days. Cities above their 10-year baseline were generally the colder, drier interior stations, while the lake-influenced stations near Lake Michigan saw a milder year than usual.
Why do freeze-thaw cycles damage concrete and masonry?
Water works into pores, hairline cracks, and mortar joints; when it freezes it expands by roughly nine percent, prying the material apart from the inside. When it thaws, the void left behind draws in even more water for the next freeze. A single cycle is harmless, but the stress is cumulative — a season of fifty to seventy cycles is what later surfaces as scaled surfaces, spalled decks, failing joints, and corroding steel. The full chemistry is covered in our freeze-thaw damage explainer.
Why are parking structures hit hardest by freeze-thaw?
Open parking decks face the sky and take every cycle directly, de-icing salt tracked in by vehicles accelerates the corrosion chemistry, and the same water that drives the frost works down to the rebar and post-tension cables below. The result is deterioration that runs years ahead of an enclosed building, which is why we recommend owners run a regular two-tier inspection routine.
Can freeze-thaw damage be prevented?
Largely, yes — freeze-thaw is one of the most predictable failure modes in commercial construction, which makes it one of the most preventable. Every cycle is at its root a water-management problem: failed sealant joints and eroded mortar are the entry points, so closing them and managing drainage gives the cycles far less to act on. That is the logic behind a deliberate waterproofing strategy rather than a patch-as-it-leaks habit.
When should owners schedule freeze-thaw repairs?
The buildings that come through a Midwest winter intact are the ones that find and document problems before the cold, scope repairs in spring, and do the real work in the warm window — not the ones that wait for a leak. Caught at the surface-scaling stage, the work stays in the range of routine concrete repair like patching, sealing, and crack injection; left until the embedded steel is involved, the same defect becomes full-depth structural rehabilitation at many times the cost.