Data current as of 2026-10-16 · Sourced from NOAA Storm Events
Over the past five years, the National Oceanic and Atmospheric Administration has recorded 216 hail storms within 25 miles of Oconomowoc, WI. Of those, 176 produced hail at least quarter-size — the threshold most insurance carriers consider potentially damaging to asphalt shingles. The largest reported hail in this window was egg-sized, which can fracture shingle mat and dent metal flashing on contact. 2026 was the most active year on record locally, with 77 documented hail events.
Check Hail History for a Specific Address in Oconomowoc| Severity | Count | What it means for roofs |
|---|---|---|
| Destructive | 17 events | Egg-size, expect mat fractures and gutter damage |
| Severe | 34 events | Ping pong-size, granule loss and bruising common |
| Significant | 125 events | Quarter-size, the standard insurance damage threshold |
| Moderate | 40 events | Marble-size, possible cosmetic damage |
| Year | Reported Hail Events Within 25 mi |
|---|---|
| 2026 | 77 events |
| 2025 | 58 events |
| 2024 | 25 events |
| 2023 | 22 events |
| 2022 | 34 events |
2026 was the busiest hail year on record locally for Oconomowoc, with 77 documented events inside the 25-mile radius. Storm activity in Oconomowoc typically peaks in spring and early summer, when the jet stream pushes Gulf moisture into the area and supercell thunderstorms become more frequent.
| Date | Location | Severity | Size | NOAA Comments |
|---|---|---|---|---|
| 2026-08-10 | 1 SW Mukwonago, WI | Significant | 1.00" | — |
| 2026-08-10 | 2 E Mukwonago, WI | Significant | 1.25" | Report from mPING: Half Dollar (1.25 in.). |
| 2026-07-27 | 1 W Oconomowoc, WI | Destructive | 2.50" | — |
| 2026-07-27 | 1 SW Lac La Belle, WI | Significant | 1.25" | — |
| 2026-07-27 | 1 ESE Lac La Belle, WI | Severe | 1.75" | — |
| 2026-07-27 | Juneau, WI | Significant | 1.00" | Two reports of one inch hail in Juneau. |
| 2026-07-27 | Neosho, WI | Destructive | 2.75" | Delayed Report - Photos of hail around 2.75 inch diameter received on social media. Time of 11:05 AM was estimated from radar. |
| 2026-07-27 | 1 NE Oconomowoc, WI | Destructive | 2.00" | — |
| 2026-07-27 | 1 S Delafield, WI | Significant | 1.00" | — |
| 2026-07-03 | 3 ESE Jackson, WI | Significant | 1.00" | Trained spotter reports 1 inch diameter hail in Jackson. |
| 2026-06-25 | 4 E Iron Ridge, WI | Significant | 1.00" | Delayed Report: Report from mPING: Quarter (1.00 in.). |
| 2026-06-24 | HERMAN CENTER, WI | Significant | 1.00" | — |
| 2026-04-18 | 3 SE Palmyra, WI | Significant | 1.00" | — |
| 2026-04-18 | Eagle, WI | Significant | 1.00" | Relayed from HAM Radio. |
| 2026-04-18 | 2 S Eagle, WI | Significant | 1.00" | — |
| 2026-04-17 | LITTLE PRAIRIE, WI | Significant | 1.00" | — |
| 2026-04-17 | EAGLE, WI | Significant | 1.00" | — |
| 2026-04-17 | EAGLE, WI | Significant | 1.00" | — |
| 2026-04-17 | Watertown, WI | Significant | 1.00" | — |
| 2026-04-15 | 2 N Menomonee Falls, WI | Destructive | 2.00" | Report from mPING: Hen Egg (2.00 in.). |
NOAA has recorded 119 high-wind events within 25 miles of Oconomowoc, WI in the past five years. Of those, 119 reached severe-thunderstorm thresholds (58+ mph). The highest measured gust was 82 mph.
| Severity | Count |
|---|---|
| Severe | 30 events |
| Significant | 89 events |
| Date | Location | Gust (mph) | Severity | NOAA Comments |
|---|---|---|---|---|
| 2026-08-18 | 2 ENE Butler, WI | 56 | Significant | AWOS station KMWC Milwaukee Timmerman Airport reports 56 mph winds during thunderstorm. |
| 2026-07-27 | 2 SW North Prairie, WI | 62 | Significant | 62 MPH wind gust measured via home weather station. Time confirmed from radar data. |
| 2026-07-27 | Juneau, WI | 65 | Severe | Trained spotter estimates 65 MPH wind gusts. Time confirmed from radar data. |
| 2026-07-03 | 1 SE Menomonee Falls, WI | 64 | Severe | Private weather station measures 64 MPH wind gust. Time confirmed from radar. |
| 2026-07-02 | 3 WSW Watertown, WI | 55 | Significant | Private weather statement measures 55 MPH wind gust. Time confirmed from radar. |
| 2026-06-10 | 1 E Fort Atkinson, WI | 75 | Severe | Trained spotter estimates 75 MPH wind gusts. |
| 2026-06-10 | FT ATKINSON, WI | 75 | Severe | Trained spotter estimates 75 MPH wind gusts in Fort Atkinson. |
| 2026-06-10 | WATERTOWN AIRPORT, WI | 60 | Significant | Public report of a 60 MPH wind gust as measured by a home weather station. |
| 2026-06-10 | REESEVILLE, WI | 60 | Significant | Fire and rescue reports a fallen tree on powerlines. Wind gust estimated from radar data, nearby observations, and damage. |
| 2026-06-10 | 3 SW Watertown, WI | 60 | Significant | Home wx station. |
| 2026-06-10 | HARTFORD, WI | 60 | Significant | Public report of a downed tree near downtown Hartford. Wind gust estimated from radar data, nearby observations, and damage. |
| 2026-06-10 | LANNON, WI | 60 | Significant | Public report a small tree snapped half way up. Wind gust estimated from radar data and damage. |
| 2026-04-17 | EAST TROY, WI | 64 | Severe | An uprooted tree. |
| 2026-04-17 | RICHWOOD, WI | 64 | Severe | A barn wall was blown down. |
| 2026-04-14 | 4 SSE Sullivan, WI | 60 | Significant | — |
| 2026-04-14 | WHITEWATER, WI | 58 | Significant | A couple trees down on the north side of Whitewater. |
| 2026-04-14 | LAKE BEULAH, WI | 64 | Severe | Several large tree downs. Another tree down on County Highway L just to the south. |
| 2026-04-14 | 1 W Oconomowoc, WI | 60 | Significant | — |
| 2026-04-14 | OCONOMOWOC LAKE, WI | 81 | Severe | A swath of scattered tree and powerline damage across the county, but with heavier concentrations of damage in some areas. There was widespread tree damage on the west side of Lake Okauchee, and also a concentration of uprooted and snapped trees, including some felled on homes, near North Prairie. Another concentration of many snapped pine trees near the intersection of Waterville Rd. and Robinhood Dr. Another concentration of trees and powerlines down near Big Bend and yet another in the Sussex area. |
| 2026-04-14 | BUTLER, WI | 49 | Significant | Multiple social media reports of tree limbs and trees down in northern and western Milwaukee. |
The most recent quarter-size-or-larger hail storm recorded by NOAA within 25 miles of Oconomowoc was on August 10, 2026. HailCheck refreshes from the NOAA Storm Events database daily, so newer events appear here as they are reported.
Oconomowoc averages roughly 43 reported hail events per year within a 25-mile radius. Significant storms (quarter-size or larger) account for 176 of the 216 events recorded over the last five years.
The largest documented hail near Oconomowoc in the last five years was egg-sized. Most Oconomowoc-area hail falls in the marble-to-quarter range, with destructive storms (egg-size or larger) appearing roughly once every few years.
Most homeowners insurance policies in WI cover hail damage to roofs, siding, and gutters under the dwelling and other-structures coverage. Coverage typically requires the damage to be tied to a verifiable storm date — which is where the NOAA hail history above (and a HAAG-style test square validation) becomes important for the claim file.
Use the HailCheck address search to enter any street address in or near Oconomowoc. HailCheck returns every NOAA hail event within a configurable radius, along with severity bands, dates, and storm narratives for Pro members.
If your property in or near Oconomowoc took on hail during one of the storms above, the standard process for documenting damage is a 10×10 foot test square inspection. A HAAG-trained reviewer counts impact indicators — granule displacement, mat fractures, and bruising — within the marked square and produces a PASS or FAIL document for the claim file.
HailCheck offers a $99 photo-based HAAG-style test square validation. You submit photos from the field, our reviewer evaluates the impact indicators and cross-references the NOAA storm dates listed above, and a written PASS/FAIL determination is returned within one business day. We do not send anyone to the roof — the validation is built around the photos you submit.
Learn About $99 HAAG-Style ValidationOconomowoc sits east of the traditional hail alley, where hail events are less frequent than the central plains but tend to be associated with strong squall lines and tropical systems. Local roof systems are less commonly hardened for hail, which can mean even moderate impacts produce claim-worthy damage.