Livonia Freeze-Thaw and Winter Pavement Data

Last reviewed 2026-07-25. Journalists, researchers, and community groups are welcome to cite any figure on this page with attribution and a link.

This page collects the actual figures behind everything else on this site. The climate data is NOAA's 1991-2020 U.S. Climate Normals for Detroit Metro Airport, station USW00094847, which sits about eleven miles due south of Livonia and is the nearest first-order observation site. Values in NOAA's normals file are published in tenths, so 1154 is 115.4 days and 425 is 42.5 inches; they are converted here.

The one number on this page that is arithmetic rather than a direct reading is the freeze-thaw day count, and the subtraction is shown below so you can check it. Everything else is quoted as published. Sources with working links are listed at the bottom. If a figure is not sourced, it is not on this page.

The freeze-thaw arithmetic

NOAA does not publish a freeze-thaw cycle count directly, but it publishes both halves of one. The normals file records the average number of days a year with a minimum temperature at or below 32 degrees, and separately the number of days with a maximum at or below 32. The first is every day the pavement gets below freezing at some point. The second is every day it never gets back above. Subtract the second from the first and what remains is the number of days a year the pavement went below freezing and came back up.

For Detroit Metro Airport on the 1991-2020 normals that is 115.4 minus 41.3, or 74.1 days a year. Broken down by season it is 38.1 days in December through February, 22.5 in March through May, and 13.5 in September through November, which sums back to 74.1. The spring and fall numbers matter more than people expect: those are shoulder-season cycles, when the ground is wet and thawing and the pavement has the least support underneath it.

Snow, and how it arrives

Livonia's snowfall normal is 42.5 inches a year, of which 32.3 inches falls in December through February. That total is less interesting than how it arrives. Thirty-six point seven days a year bring at least a tenth of an inch, but only 13.1 bring an inch or more and only 4.1 bring three inches or more. Storms big enough to trigger Livonia's city-wide plowing response, which starts at four inches, are a handful of events a season.

The distinction matters for pavement because it is the small, frequent events that produce the most salting. A trace of snow or a freezing drizzle gets treated the same way a real storm does, and there are almost three times as many of those days as there are inch-plus days. That is the pattern that keeps brine on the road, and on your driveway, more or less continuously from December through March.

The salt program around Livonia

Winter road maintenance in and around Livonia is split across three agencies. MDOT runs the state trunklines, including I-96, I-275 and M-14. Wayne County's Department of Public Services handles most of the major surface roads, which in Livonia means the mile roads and the main north-south arteries. The City of Livonia handles approximately 360 miles of neighborhood streets on its own tiered plan.

The volumes are substantial and they swing hard between winters. MDOT's Metro Region spread more than 111,000 tons in the 2025-26 winter, roughly 35 percent above average, after a mild 2023-24 winter in which statewide trunkline use fell 37 percent, or 175,000 tons and around $10 million. Wayne County pre-wets its rock salt with liquid brine, which activates it faster on contact, and built a new salt dome in Plymouth Township in the summer of 2024.

The ground under the pavement

The Blount series is the characteristic till soil across much of this part of southeastern Michigan. The USDA official series description classes it as fine, illitic, mesic Aeric Epiaqualfs, formed in till on wave-worked till plains and relict near-shore zones of Wisconsinan age, somewhat poorly drained, with saturated hydraulic conductivity described as moderately low in the solum and low in the dense till beneath. The particle-size control section averages 35 to 45 percent clay.

That combination, high clay content and poor drainage, is why water reaching the base under a Livonia driveway tends to stay there. Classic work on frost action in Michigan put the state's freezing index at roughly 600 in the southern counties, rising toward 1800 in the Upper Peninsula, and found that during the thaw cycle the moisture content of fine-grained soils often approaches the liquid limit, at which point the soil stops supporting load. That study also noted bituminous surfaces suffer most severely under those conditions.

MDOT describes the surface consequence plainly: moisture seeps into the pavement and freezes, the ground expands and pushes the pavement up, and when temperatures rise the ground returns to level, leaving a void between the pavement and the ground below. Traffic then breaks the unsupported span. That sequence is why the [road salt guide](/road-salt-and-livonia-driveways) treats brine as a freeze-thaw multiplier rather than a corrosive.

The working season, in NOAA dates

Sealcoating in Livonia is bounded by weather, not by preference. NOAA's normals give median freeze dates for Detroit Metro that define the outer edges of the season, and the practical working window sits inside them, because sealer wants surface temperatures comfortably above 50 degrees and about 24 hours dry afterward, not merely above freezing.

The median last spring freeze at 32 degrees is April 20 and the median first fall freeze is October 24, giving a median freeze-free season of 185 days. In practice that means May through early October for sealing, with the good weekends in May, June, and September booking out first. Crack filling has a slightly longer window on either end, and cold-patch repairs can be made any time, though they are a stopgap rather than a fix.

Sources & Methodology

Every figure above was taken from the primary sources below (accessed 2026-07-25). Where a number is derived (arithmetic on published figures) or covers a broader period or area, the text says so.

1. NOAA NCEI, 1991-2020 U.S. Climate Normals, Detroit Metro Airport (USW00094847) — Direct data service response for the annual and seasonal normals. Values are published in tenths: ANN-TMIN-AVGNDS-LSTH032 of 1154 is 115.4 days, ANN-TMAX-AVGNDS-LSTH032 of 413 is 41.3 days, and ANN-SNOW-NORMAL of 425 is 42.5 inches. Freeze dates come from the PRBLST and PRBFST fields at the 50 percent probability level.
2. MDOT winter salt use, Metro Detroit region, 2025-26 winter (ClickOnDetroit) — Source for the 111,000-plus tons figure and the statement that it ran about 35 percent above average.
3. Wayne County winter operations (CBS News Detroit) — Source for roughly 4,500 lane miles, more than 100 trucks, the practice of pre-wetting rock salt with liquid brine, and the salt dome built in Plymouth Township in summer 2024.
4. Michigan road salt use and the 2023-24 mild winter (Michigan Public) — Source for the 37 percent statewide trunkline reduction, 175,000 tons, roughly $10 million saved, 9,700 trunkline miles, 90,500 county road miles, and Oakland County at 66 percent of normal.
5. City of Livonia snow removal policy — Source for approximately 360 miles of city-maintained neighborhood streets, the primary and secondary route tiers, and the Level I, II and III thresholds at four and eight inches.
6. USDA NRCS Official Series Description, BLOUNT series — Source for 35 to 45 percent clay in the particle-size control section, the somewhat poorly drained class, low saturated hydraulic conductivity in the dense till, and formation in Wisconsinan-age till in Michigan.
7. Frost Action in Michigan, Highway Research Board Special Report 2 — Source for the Michigan freezing index range of roughly 600 in the south to 1800 in the Upper Peninsula, and for the finding that fine-grained soil moisture often approaches the liquid limit during thaw, with bituminous surfaces suffering most severely.