Hail and Roofing Rules Across the Denver Metro

Five counties, one hail season

NOAA's Storm Events Database records 599 hail events of 1 inch or larger across Denver, Arapahoe, Jefferson, Adams and Douglas counties from 2016 through 2025 (NCEI Storm Events Database). Arapahoe County has the most, and Douglas County's reports are spread over 48 separate days, more than any of the other four.

A hailstorm that crosses a county line is counted once in each county, so the five figures overlap where a single storm tracked across several of them.

Storms that shaped metro roofs

• May 8, 2017, Jefferson and Denver counties. The database logs 2.75-inch hail at Edgewater, with the $2.3 billion estimate covering the entire episode, and 2.5-inch hail in Denver the same day.
• June 19, 2018, Arapahoe County. Three-inch hail at Englewood carries a $276.4 million estimate that the record describes as the total storm damage summary for the event.
• May 30, 2024, Denver County. Hail of 2.75 inches near Denver International Airport, including Northfield and Central Park, is the largest stone the database records in Denver County from 2000 through 2025.
• May 10, 2023, Adams County. Strasburg took 2.75-inch hail.
• June 8, 2019, Douglas County. Castle Rock recorded 2.5-inch hail.
• May 18, 2025, Arapahoe and Adams counties. An EF2 tornado touched down south of I-70 in Arapahoe County before doing EF2 damage to numerous properties in Bennett.

Arapahoe, Douglas and Jefferson counties are also named in FEMA's major disaster declaration DR-4731 for severe storms, flooding and tornadoes beginning June 8, 2023.

Denver's contractor license

Denver's contractor licensing page says Community Planning and Development issues licenses and certificates to individuals and companies that do construction and trade work in the city, and that a supervisor certificate, or an employee who holds one, is required before a contractor's license is issued. The city runs a contractor license search you can use before you sign anything.

Denver's Roofing Guide and Checklist, updated April 11, 2024, names two roofing license types. Membrane roofs must be installed by a D-Roof Covering/Waterproofing licensed contractor, while a D-Roof Shingles licensed contractor may install small membrane areas on shingle jobs, such as porches and patios.

When a Denver roof needs a permit

The same checklist sets these rules:

• On buildings under 25,000 square feet, a repair needs a permit when it covers more than 10% of the roof or two roof squares, whichever is smaller.
• Every new roof penetration, such as a skylight, pipe or solar array, needs a permit; roof coatings do not.
• Where two or more layers of roof covering exist, the roof must be removed to the deck.
• Shingle wind ratings step up from 115 mph east of Federal Boulevard to 125 mph between Federal and Sheridan, and 140 mph from Sheridan to Kipling.
• One- and two-family asphalt shingle roofs get a final roof inspection.

Colorado's statewide roofing contract law sits on top of these city rules; the homepage walks through what it requires.

Denver-area roofers on the National Roofing Directory

The directory lists roofers in Denver, Aurora, Lakewood and Littleton. You can also browse roofers in Denver, roofers in Aurora or roofers in Lakewood directly.

Frequently asked questions

Do I need a permit to fix hail damage on a Denver roof?

It depends on the size of the repair. Denver's checklist requires a permit once a repair exceeds 10% of the roof or two roof squares, whichever is smaller, on buildings under 25,000 square feet, and a full replacement is well past that line.

How do I check a Denver roofing contractor's license?

Use the city's contractor license search on denvergov.org. The roofing checklist refers to D-Roof Shingles and D-Roof Covering/Waterproofing licenses, so confirm the company holds the type that matches your roof.

What is the largest hail recorded in Denver County?

NOAA's Storm Events Database lists 2.75-inch hail near Denver International Airport on May 30, 2024 as the largest in Denver County from 2000 through 2025. Neighboring Arapahoe County logged 3-inch hail at Englewood on June 19, 2018.