Casper hail storm history
Natrona County·NOAA NCEI Storm Events Database·~75-day publication lag
Casper lies in the North Platte River corridor of central Wyoming, where afternoon convection triggered by the surrounding Casper Mountain and Rattlesnake Range produces consistent hail activity throughout the warm season. Natrona County's position in this orographic lift zone means hailstorms that develop locally often track northeast across the county, exposing residential and commercial properties to recurring severe weather risk.
Check if your roof was damaged by recent hail
Hail activity in Casper peaks during July and June, with secondary activity extending into May and August. The Wyoming Climate Atlas 56-year record for Casper shows July averaging 9.4 thunderstorm days—the highest of any month—reflecting the role of summer heating in triggering mountain-induced convection. Storm systems that develop in this corridor tend to organize rapidly and produce hail capable of functional damage to roofing, siding, and vehicles.
Annual frequency — last 10 years
When hail hits — monthly pattern
Avg events per month · all years · NOAA data
All recorded hail events
Of 36 recorded events, 14 (39%) reached 1.5" or larger — the threshold for likely functional damage on standard asphalt shingles.
A trained spotter reported nickel size hail to the west of Mills.
Trained spotters reported hail from the size of pennies to quarters from south of Mills to Casper Mo…
Time estimated via radar. Emergency manager reports golf ball size hail.
A thunderstorm moved southeastward and brought local severe hail. Hail from penny to occasionally qu…
From Glenrock Police Department. Hail ranged from quarters to half dollar size.
A trained spotter reported nickel to golf ball size hail covering Highway 259 south of Midwest to a …
A trained spotter reported golf ball size hail to the west of Bar Nunn.
A trained spotter reported quarter size hail to the west of Casper.
A trained spotter reported nickel size hail to the west of Casper.
Trained spotters observed quarter-sized hail in and around Evansville.
Firefighters reported golf ball size hail along Cole Creek Road north of Evansville, Wyoming.
The public reported ping pong ball sized hail north of Casper, Wyoming along Interstate 25 near the …
A storm moved into Natrona County and rapidly strengthened as it moved toward Highway 220 southwest …
The Natrona County Emergency Manager reported up to nickel size hail at the Bear Trap Music Festival…
A trained spotter reported golf ball sized hail.
Trained spotters reported anywhere from penny to quarter size hail on the east side of Casper and in…
Hail was reported along Interstate 25 at mile marker 169 near Glenrock.
Law enforcement reported quarter size hail at the Natrona County airport.
Ping pong ball size hail was observed south of Glenrock.
Trained spotters reported from quarter to golf ball size hail throughout much of Casper.
Quarter size hail was observed a mile southwest of Glenrock.
A trained spotter reported nickel to quarter size hail, two miles east-southeast of Evansville.
A strong thunderstorm produced penny sized hail in Bar Nunn north of Casper.
A trained spotter reported penny-sized hail on Casper Mountain.
NOAA National Centers for Environmental Information Storm Events Database. Publication lag is approximately 75 days — current-year events may be incomplete.
NOAA Storm Events Database ↗