When to Stop Mowing Your Lawn in Fall: The Last Mow Where You Live

Stop mowing your lawn in fall when the grass stops growing. For cool-season lawns that is when daytime highs stay below about 50°F, which in a normal year means late October in Minneapolis, mid-November in Chicago and Des Moines, and early December in Philadelphia. Warm-season lawns such as Bermuda grass and zoysia stop when the first frost sends them into dormancy.

Most guides give a month for your whole state. Below are normal-year dates for 22 cool-season and 18 warm-season cities, worked out from NOAA’s 1991–2020 climate normals and checked against what three extension services say about their own states.

Two temperature signals that end the mowing season

Cool-season grasses, which include Kentucky bluegrass, tall fescue, perennial ryegrass and the fine fescues, slow down as fall cools and then stop. Extension services describe the stopping point in two slightly different ways. Iowa State University Extension ties it to the daytime high: the foliage of cool-season grasses such as Kentucky bluegrass²

stops growing when daytime high temperatures are consistently below 50 degrees Fahrenheit

Cornell University’s turfgrass program uses the average of day and night instead:³

Top growth continues until the average daily temperature is consistently below 50°F.

Both are useful, but they don’t mark the same day. The daily mean drops below 50°F first, a median of 26 days before the daytime high does.¹ Read the earlier date as the point where growth slows and you can mow less often. The later date is when the last mow usually comes. Keep mowing in between whenever the grass needs it; Purdue’s advice is to continue as long as the grass is growing.⁴

When lawns stop growing in your city

We placed NOAA’s monthly normal temperatures at the middle of each month, joined them day by day, and found the first fall day each signal drops below 50°F at the weather station nearest each ZIP code.¹ The frost column is the median date of the first 32°F night at that station; half of years bring it earlier.

These are normal-year dates. A warm November can keep a lawn growing for weeks longer, and a cold snap can end it early. For any other ZIP code, look up your frost dates and their odds.

Do the dates match local extension advice?

Three extension services publish a typical end of the mowing season for their own state. We compared them with our dates for towns in those states:

In Iowa and Minnesota the daytime-high date lands right on the published timing, within days.^2,5 Purdue’s Indiana guidance sits between the two dates.⁴ So treat the daytime-high date as your realistic last mow, and the mean date as the start of the slowdown.

Why the first frost isn’t your stop signal

Many guides tell you to stop mowing at the first frost, or a week before it. For cool-season grass, the data says otherwise. Across 27,472 ZIP codes in the lower 48 states where both dates occur in a normal year, the daytime high falls below 50°F after the median first frost in 99.5% of them, a median of 33 days later.¹ By the extension temperature rules above, a cool-season lawn keeps growing on the mild afternoons that follow a first frost.

The opposite is also true in the South. In 32% of ZIP codes, the normal daytime high never falls below 50°F at all, including nearly all of Texas, Florida, Georgia and the Gulf Coast. There the 50°F rule never applies, and grass type decides when you stop. To time frost protection for the garden instead, see when to cover plants for frost.

Warm-season lawns: the first frost ends the season

Bermuda grass, zoysia, centipede and St. Augustine grass work differently. Mississippi State University Extension says warm-season grass keeps growing until the first frost marks the beginning of dormancy.⁹ Clemson’s factsheet says zoysia turns brown with the first fall frost and stays dormant all winter.¹¹ So for these lawns, the median first frost is the realistic last-mow date:

Where a frost comes in only some years, as in Phoenix, Tampa and Miami, there is no reliable stop date: mow when the grass needs it. Not sure which kind of grass you have? Our guide to cool-season vs. warm-season grass shows how to tell.

How short to cut the last mow

Advice on the final cut ranges from “cut it short” to “leave it alone.” The extension sources agree on one thing: don’t scalp the lawn.

avoid the urge to set the mower down and scalp your lawn

Purdue explains that photosynthesis is still high in fall, and the leaf you leave on stores energy for winter and spring.⁴ The sources differ on small adjustments:

• Illinois Extension: the first and last mowing can be slightly shorter, but grass left very tall at the end of fall encourages weeds and disease.⁶
• NDSU Extension (North Dakota): make the final mowing at 2 inches, because tall grass is more likely to mat down and get snow mold.⁷
• University of Minnesota: keep the lawn at 3 inches or higher, and keep it mowed to height before winter, since grass left too long can bring disease and vole activity.⁵
• Warm-season grasses: UGA Extension in Forsyth County suggests cutting Bermuda, centipede and zoysia at the top of their 1–2-inch range, 2 inches, going into fall.¹² Mississippi State suggests raising St. Augustine grass to 3 inches for winter hardiness.⁹

Put together: for a cool-season lawn, the low end of its normal range is as short as any of these sources goes (NDSU’s 2 inches is the bottom of the Kentucky bluegrass range). For warm-season grass, the advice is the top of the range. Either way, lower the mower in steps, because Illinois Extension’s rule is never to remove more than a third of the blade in one cutting.⁶ The normal ranges come from Illinois Extension for cool-season grasses and Clemson for warm-season grasses.^6,10

Mulch the leaves with the mower

Your last few mowings can also deal with the leaves. Purdue’s turf team says oak and maple leaves can be mulched into the lawn with a mower without harming the soil or the grass. In its summary of research, mulched leaves didn’t add thatch, disease or weeds, and didn’t change soil pH.⁸

The limit is the amount. When leaves cover the lawn so thickly that you can’t see the grass, rake some off first, or the layer can smother the turf. Dry leaves mulch more easily than wet ones.⁸ The University of Minnesota also suggests bagging or raking up heavy debris at the last mow of the season.⁵

Signs the season is over

Temperatures give you a date to plan around; the grass gives you the final answer. Use the one-third rule as your test. To keep a 3-inch lawn, the University of Minnesota says to mow before it reaches 4.5 inches.⁵ If a week or more after your last cut the lawn still hasn’t grown enough to need mowing by that rule, and the daytime highs have settled below 50°F, you have probably made your last mow.

If the weather turns warm again and the grass starts growing, mow again. Wait for wet grass to dry first; Illinois Extension advises against mowing it wet.⁶

Before you put the mower away

• Sharpen the blade. A dull blade tears grass and leaves it more open to disease.^6,5
• Time the last feeding. On cool-season lawns, the late-fall feeding is timed around the last mowing; see when to fertilize your lawn. On warm-season lawns, UGA warns that fall nitrogen can delay dormancy and expose the grass to cold injury.¹²
• Keep watering in a dry fall. UGA notes that warm-season lawns still need about an inch of water a week as they slow down.¹² Our guide to how much to water your lawn shows how much your rain already covers.
• Store the mower by its manual. Fuel, oil and battery storage differ by model, so follow the manufacturer’s instructions.

Related guideWhen to Fertilize Your Lawn: A Schedule by Grass Type and Climate

How we worked out these dates, and their limits

Each date uses NOAA NCEI’s 1991–2020 monthly normals for daily mean and daily maximum temperature at the station nearest the ZIP code.¹ We put each month’s value at mid-month, interpolated the days in between, and took the first fall day below 50°F. “Consistently below 50°F” is our reading of that crossing in a normal year; real years cross earlier or later. Frost dates are the station’s median first 32°F and 28°F nights.

Three limits matter. First, some guides give soil-temperature cutoffs between 40°F and 50°F. We found no extension source for a soil threshold for the end of mowing, and our dataset has no soil temperatures, so we don’t estimate one. Second, a station can be a few miles away, and a valley or hilltop yard can differ by a week or more. Third, these are averages, not a forecast. The methodology page explains how every date on this site is calculated.

For the rest of the season’s yard work, see our mowing and watering guides. If your lawn is thin, check the last safe day to overseed before next fall, or in the North try dormant seeding this winter.