Colorado Snow Day Calculator: Chances, Mountain Snow and School Hours

In Colorado’s big cities, 7 to 9 inches of snow is where schools close about half the time, by our rule of thumb. Colorado Springs sits at 7 inches, Aurora and Denver at 7.5, Fort Collins at 8, Thornton at 8.5 and Lakewood at 9.

The mountains are another world. Colorado’s snowiest NOAA station, near Crested Butte at about 9,600 feet, normally records 389 inches a year; the least snowy, John Martin Dam, gets 9.7. Jeffco Public Schools lists its mountain schools as a group of their own, and says predicting weather across a large, varied district “presents a challenge.”

Colorado law counts scheduled hours: 1,080 a year for secondary students and 990 for elementary, on at least 160 days. Actual hours may fall slightly short for closings the local board deems necessary for safety, a small cushion shared with conferences and staff training.

How much snow closes school in Colorado?

Between 7 and 9 inches in the six cities on our map, by our rule of thumb. That is the amount at which schools close about half the time.

Colorado's six largest cities: normal snowfall a year (NOAA 1991–2020) and the snowfall and wind chill at which, by our rule of thumb, schools there usually close.

Our rule of thumb: the usual closing point is 0.5 × (normal snowfall a year)^0.7, the cold point the normal December–February low minus 45°F. How the calculator works.

Lakewood, with 59.9 inches a year, has the highest point, 9 inches. Colorado Springs, with 43.9, has the lowest, 7, and Denver’s 46.8 inches put it at 7.5. For other states’ cities, see how much snow it takes to close school.

Totals are only part of it. Denver Public Schools bases the call on “the expected accumulation of snow, the size of the storm and its duration,” and the calculator weighs similar things. Snow overnight and during bus hours counts in full, snow during the school day counts 45%, and gusts of 25 mph or more while an inch or more falls make it count more.

On a storm night, the Weather Service office in Boulder publishes snow probability maps: the chance that snow will top 1, 2, 4, 6, 8, 12 or 18 inches, and a likely range drawn from the National Blend of Models. They make a useful check beside the calculator’s reasons.

Do snow days have to be made up in Colorado?

Only if closings cut too deep into the hours. Under C.R.S. 22-32-109, schools may not be “scheduled to have fewer than one thousand eighty hours” of planned teacher-pupil instruction and contact for secondary students. Elementary students need 990, full-day kindergarten 900 and half-day kindergarten 450. No school may be in session fewer than 160 days without the Commissioner of Education’s prior approval.

The key word is scheduled. Actual hours may drop to 1,056 for secondary and 968 for elementary (870 and 435 for full- and half-day kindergarten) for parent-teacher conferences, staff in-service programs and closings the board deems necessary for students’ health, safety or welfare.

That leaves a cushion of 24 hours for secondary students, 22 for elementary, 30 for full-day kindergarten and 15 for half-day. It is shared with conferences and training, not set aside for snow. On a 6-hour day, 24 hours is 4 days, before any conference time is counted.

In extraordinary circumstances, the Commissioner may waive the hour requirement on the district board’s application, but only if meeting it would mean scheduling hours when few students would attend and they would gain little for the cost. Calendar changes normally need 30 days’ notice, but not changes caused by emergency closings. From 2025–26, under a 2024 law, the state education department collects every district’s school closures, snow days and instructional hours and publishes a report.

We read the 2024 edition of the Colorado Revised Statutes, so changes made in the 2025 and 2026 sessions are not reflected. We found no penalty text for falling short.

Can Colorado schools switch to remote learning instead?

The state statute we read does not say. Nothing in C.R.S. 22-32-109 addresses whether remote teaching on a weather day counts toward the hours, and we did not find a state education department or State Board rule on it.

Big districts, though, name it as an option. Denver Public Schools‘ superintendent decides whether to “go remote or close.” Jeffco uses remote learning days when weather closes schools for more than one day in a row. A one-day closure is a snow day, with no instruction, and Jeffco saves the 2-hour delay for extreme weather. Our guide to snow days, delays and e-learning days explains each.

Where does Colorado get the most snow?

High in the mountains. The station near Crested Butte, about 9,600 feet up, has the highest normal of Colorado’s 196 NOAA weather stations: 389 inches a year. Climax, at about 11,340 feet, gets 294.7, and Winter Park 214.

Normal snowfall a year and normal December to February low at each of the 196 weather stations in Colorado with a snowfall normal in NOAA's U.S. Climate Normals for 1991–2020, with each station's location, elevation and how complete its record is.

The 10 snowiest and 5 least snowy of 196 stations in Colorado

Download “Normal snowfall at Colorado weather stations, 1991–2020” (CSV, opens in Excel)

Built from: U.S. Climate Normals, 1991–2020 (National Centers for Environmental Information).

Next come a second Crested Butte station (203), Coal Creek Canyon (194.7), Vail (189.2), Breckenridge (184.6) and Steamboat Springs (184.5). Our rule tops out at 15 inches, which it reaches at about 129 inches of snow a year, so every one of those stations sits at the ceiling.

The least snowy stations sit lower. John Martin Dam, about 3,810 feet up, normally gets 9.7 inches, Uravan 11.1, Gateway 11.2 and the station near Grand Junction 12.6. The middle of the list is about 49 inches. Of the 196 stations, 51 are what NOAA calls standard, with 24 or more years of records, and 145 are provisional, with at least 10.

How cold does it have to be to close school in Colorado?

Colorado’s school law sets no temperature, and the Denver and Jeffco pages we read name no number, so the calculator uses our cold point: a wind chill of −26°F to −29°F in the map’s cities, by our rule of thumb. It is the normal December-to-February low minus 45°F. Districts elsewhere that publish a number are in our guide to cold-weather closings.

Fort Collins, with a normal winter low of 16.4°F, sits at −29°F. Denver and Lakewood, near 19°F, sit at −26°F. The calculator checks the wind chill from 5 to 9 AM.

Weather Service alerts weigh in. An Extreme Cold Watch means dangerous cold is possible but still uncertain; an Extreme Cold Warning means it is expected or happening, and it raises the calculator’s chance more. Both names replaced the wind chill alerts on or about October 1, 2024.

Who decides, and when do families hear?

Your local board of education sets the calendar and decides closures; the Commissioner handles waivers. Denver Public Schools consults weather services, the City of Denver’s plowing schedules, the state transportation department and neighboring districts, and aims to make the call by 5 a.m.

Jeffco Public Schools starts the night before and decides before 5:30 a.m. Its weather team uses a professional forecast company and the National Weather Service. It asks whether buses and snow removal can work, whether meals can be served, and what the forecast says for later in the day. After-school activities are decided by 1 p.m.

Jeffco also weighs the cost: the schedules of 66,500 students’ families and 14,000 employees. On closing, it says, “Most often, the answer is no.” If your district is like that, set the calculator to rarely closes, and check your district’s website, app, or local TV and radio for the decision. Our guide to how schools decide snow days covers the rest of the country.

Snow days in Colorado

• Snow
  • 7 inches in Colorado Springs
  • 7.5 in Denver
  • 9 in Lakewood
• Mountains
  • 389 inches near Crested Butte
  • Rule tops out at 15 inches
• Cold
  • Our cold point −26°F to −29°F
  • Extreme Cold Warning
• School hours
  • 1,080 or 990 scheduled
  • 160 days
  • Small cushion for closings
• Remote days
  • Not in the statute we read
  • Denver can go remote
  • Jeffco for multi-day closures
• Who decides
  • Local board
  • Denver by 5 AM
  • Jeffco before 5:30 AM

Questions people ask

How much snow does it take to cancel school in Colorado?

The state sets no number. By our rule of thumb, it is 7 to 9 inches in the big cities, and Denver says it weighs the expected snow, the size of the storm and how long it lasts.

Do Denver schools go remote on snow days?

They can. Denver’s superintendent decides whether to go remote or close, aiming to call it by 5 a.m.

What time does Jeffco announce snow days?

Before 5:30 a.m. Planning starts the night before, and after-school decisions come by 1 p.m.

Do Colorado schools make up snow days?

Only if closings push actual hours below the floors: 1,056 for secondary students and 968 for elementary. The cushion above them is small and shared with conferences and training.

Sources: Colorado Revised Statutes 2024, Title 22 (C.R.S. 22-32-109 and 22-2-310); Jeffco Public Schools, weather; Denver Public Schools, weather.

Facts checked October 29, 2026.

Updated October 29, 2026