Rockford hail storm history
Winnebago County·NOAA NCEI Storm Events Database·~75-day publication lag
Winnebago County, where Rockford is located, has experienced 8 documented hail events of 1 inch or larger over the past 10 years, with 2 of those events reaching the 1.5-inch threshold capable of functional roof damage. Rockford sits in northern Illinois where fast-moving frontal systems and squall lines from the Plains produce the highest hail frequency in the state. The largest recorded hail event in Winnebago County measured 1.5 inches in diameter, occurring on July 10, 2025.
Hail in Rockford occurs most frequently during April, May, and June, when organized severe weather systems move northward with the jet stream. March and July represent secondary risk months in Winnebago County. The spring peak aligns with the seasonal shift of storm tracks from the southern Plains toward northern Illinois, making late spring the period of highest hail exposure for Rockford homeowners.
Annual frequency — last 10 years
When hail hits — monthly pattern
Avg events per month · all years · NOAA data
All recorded hail events
Of 112 recorded events, 32 (29%) reached 1.5" or larger — the threshold for likely functional damage on standard asphalt shingles.
Hail lasted for 10 minutes with the largest hail 1.5 inches in diameter.
A photo was shared with quarter size hail next to a quarter coin.
Quarter size hail was reported southwest of Kirkland. Some melting occurred prior to the observatio…
A photo shared on social media showed quarter size hail near Grand Detour.
Dime to quarter sized hail.
Photos showed hail at least 2 inches in diameter.
Quarter size hail was reported between Loves Park and Rock Cut State Park.
Ping pong ball size hail was reported at Route 64 and Blackhawk Road.
Nickel to quarter size hail was reported near Center and Main Streets.
Quarter to ping pong ball size hail was reported.
Brief penny to quarter size hail was reported.
Reported in Freeport from a separate supercell before the derecho straight-line wind damage occurred…
Hail 2 inches in diameter was reported near Interstate 39.
Emergency management relayed public reports of 1 to 3 inch diameter hail.
Golf ball size hail was reported on Interstate 88 near Ashton.
A morning storm produced heavy rain and pea to penny size hail in Stephenson County.
A trained spotter reported hail up to the size of pennies to quarters.
Hail ranging from 1.5 to 2.0 inches in diameter was reported from multiple locations around and to t…
Hail was mostly pea size with some larger penny size hail stones.
Quarter size hail was reported at multiple locations.
Quarter to half dollar size hail was reported in numerous locations including near north State Stree…
Nickel size hail was reported 2 miles north of Belvidere.
There were multiple reports of quarter to golf ball size hail in Machesney Park. Damage to cars was…
Nickel size hail was reported at the intersection of East State Street and Regan Street.
Nickel size hail was reported near Harrison Avenue and Mulford Road.
There were also reports of 55 to 60 mph winds and very heavy rainfall with visibilities around 200 f…
Quarter sized hail near Barker Rd.
Winnebago County's hail event count of 8 events over 10 years reflects the NOAA Storm Events Database reporting density for this region. The database prioritizes events meeting damage thresholds or producing significant hail rather than comprehensive capture of all hail occurrences, so actual event frequency may be higher than records indicate. Current-year data is excluded from the annual frequency table until October, when NOAA's Storm Events Database has processed the full hail season accounting for the standard 75-day reporting lag.
NOAA Storm Events Database source