Boulder County, Colorado severe weather history spans 513 recorded events between 1953 and 2025. The dominant hazard is hail, accounting for 69.4% of all recorded events. It ranks #830 nationally and #20 in Colorado.
513
Recorded events
6
Direct deaths
25
Direct injuries
$299.4M
Property damage
The record
What the Boulder County, Colorado severe weather history record shows
Across the archive, Boulder County, Colorado severe weather history averages 7.1 recorded events a year. The busiest stretch on record is the 2010s, with 170 events logged in that decade alone. Roughly 85 events fall before 1990 and 428 from 1990 onward — a gap that reflects the expansion of NOAA reporting practice as much as the weather itself.
The deadliest hazard in the Boulder County, Colorado record is flash flood, responsible for 4 direct deaths. The costliest is flood, with $297.1M in reported property damage. In total, 7 distinct hazard types appear in this county archive, each listed with its own dated record below.
By hazard type
Every hazard type recorded in Boulder County
| Hazard | Events | Deaths | Damage | Max | Span |
|---|---|---|---|---|---|
| Hail | 356 | 0 | $1.0M | 3 | 1962–2025 |
| Thunderstorm Wind | 72 | 0 | $26K | 87 | 1957–2024 |
| Lightning | 35 | 2 | $117K | 0 | 1996–2019 |
| Flash Flood | 31 | 4 | $835K | 0 | 1997–2021 |
| Tornado | 11 | 0 | $283K | F2 | 1953–2015 |
| Flood | 5 | 0 | $297.1M | 0 | 1999–2015 |
| Heavy Rain | 3 | 0 | $0 | 0 | 2004–2019 |
Decade by decade
Boulder County, Colorado severe weather history by decade
Reporting practice changed over time — early decades are undercounted, not calmer.
Tornado tracks
Paths crossing this county
10 mapped tornado paths intersect this county: 10 touched down inside it and 0 crossed in from a neighbouring county. This comes from path geometry, not county-tagged reports.
| Date | Scale | Deaths | Injuries | Path length | Origin |
|---|---|---|---|---|---|
| 2015-06-04 | EF3 | 0 | 0 | 6.7 mi | Touched down here |
| 1980-10-15 | EF2 | 0 | 0 | 1.5 mi | Touched down here |
| 1997-06-06 | EF1 | 0 | 0 | 0.1 mi | Touched down here |
| 1996-06-16 | EF1 | 0 | 0 | 1.5 mi | Touched down here |
| 1980-04-30 | EF1 | 0 | 0 | 5.7 mi | Touched down here |
| 1978-05-17 | EF1 | 0 | 0 | 0.5 mi | Touched down here |
| 1955-05-12 | EF1 | 0 | 0 | 0.1 mi | Touched down here |
| 1953-09-17 | EF1 | 0 | 0 | 0.1 mi | Touched down here |
| 1990-06-01 | EF0 | 0 | 0 | 0.2 mi | Touched down here |
| 1976-06-04 | EF0 | 0 | 0 | 0.1 mi | Touched down here |
Significant events
Deadliest events on record in Boulder County
| Date | Type | Location | Deaths | Injuries | Damage |
|---|---|---|---|---|---|
| Sep 12, 2013 | Flash Flood | RIVERSIDE | 3 | 2 | $0 |
| Jul 14, 2019 | Lightning | ELDORADO CANYON STATE PARK | 1 | 1 | $0 |
| Sep 12, 2013 | Flash Flood | NIWOT | 1 | 0 | $0 |
| Jul 12, 2000 | Lightning | ALLENS PARK | 1 | 0 | $0 |
| Aug 2, 1986 | Hail | 0 | 6 | $0 | |
| Sep 12, 2013 | Flood | SUPERIOR | 0 | 3 | $297.0M |
| Jul 10, 2000 | Lightning | BOULDER | 0 | 3 | $0 |
| Jul 24, 2000 | Lightning | LONGMONT | 0 | 2 | $0 |
From the record
What the reports say
Written by National Weather Service staff at the time of the event · public domain
Two hikers were struck by lightning on Bear Peak off the Bear Peak Trail. The male hiker sustained a direct lightning strike and died later at the hospitail. The female hike sustained minor injuries from an indirect strike.
In Boulder, many vehicles were abandoned near Lookout Road and Spine due to floodwaters. Significant flooding was reported at the Justice Center; the Juvenile Detention Center had to be evacuated to the second floor. Floodwaters to a depth of 2 feet inundated Hawthorne Street in north Boulder. Moderate flooding was observed along Boulder Creek. Boulder Canyon was closed due to flash flooding. Numerous rock and mudslides made Lefthand Canyon impassable. Major structures were lost in Jamestown. In Lyons, rock and mud slides were also reported and the Waste Water Treatment Plant was breached. An 80-yr old man was killed when his truck was swept into the St. Vrain River. He had returned to his home to look for his wife. His vehicle was found 200 yards from their residence. In town, 82 properties were destroyed. Mandatory evacuations were ordered in Longmont, along the Lefthand and St. Vrain Creeks. In Longmont, 53 properties were destroyed.
A climber was struck and killed by lightning as he and a companion were ascending a sheer rock face, near the summit of Longs Peak. Lightning struck the victim, who was using climbing ropes and a harness, killing him instantly. His friend was not injured.
Context
Risk, population and federal disasters
Relatively Moderate
FEMA NRI risk rating
328,961
Population (ACS)
$756K
Median home value
19
Federal declarations
| Declared | Incident | Title | Type |
|---|---|---|---|
| Jul 31, 2024 | Fire | STONE MOUNTAIN FIRE | FM |
| Dec 31, 2021 | Fire | WILDFIRES AND STRAIGHT-LINE WINDS | DR |
| Dec 30, 2021 | Fire | MARSHALL FIRE | FM |
| Oct 17, 2020 | Fire | CALWOOD FIRE | FM |
| Mar 28, 2020 | Biological | COVID-19 PANDEMIC | DR |
| Mar 13, 2020 | Biological | COVID-19 | EM |
Quick answers
Frequently asked
How many severe weather events have been recorded in Boulder County, Colorado?
513 events are on record between 1953 and 2025, causing 6 direct deaths and $299.4M in property damage.
What is the most common severe weather hazard in Boulder County?
Hail, with 356 recorded events — 69.4% of everything in the archive for this county.
How many tornadoes have crossed Boulder County?
10 mapped tornado paths intersect the county boundary; 10 of them touched down inside it. This is derived from path geometry, not county-tagged reports.
How many federal disaster declarations cover Boulder County?
19 federal disaster declarations from FEMA include Boulder County, each tied to a specific incident period.
How risky is Boulder County compared with the rest of the country?
FEMA's National Risk Index rates Boulder County as relatively moderate risk, placing it in the 91 percentile of its state for expected annual loss.
Where does the Boulder County, Colorado severe weather history data come from?
Every figure is drawn from United States federal public-domain records: NOAA/NCEI Storm Events for the event archive, NOAA SPC SVRGIS for mapped tornado paths, FEMA for disaster declarations and risk ratings, and the U.S. Census for population context. Dates are shown in UTC and recent entries may still be revised by NOAA.
Nearby
Neighbouring counties
- Broomfield County 48
- Bent County 290
- Chaffee County 48
- Baca County 621
- Cheyenne County 851
- Clear Creek County 35
Cite this page
“Boulder County, Colorado.” Severe Weather History. severeweatherhistory.com/county/colorado/boulder-county/ · Data: NOAA/NCEI, FEMA, U.S. Census — public domain.