Hail size 1"
Deerfield Dane County
“(MKX)”
— NOAA / SPC storm report
Hail in Waterloo Apr 14, 2026
The radar-estimated size surface caught this storm, reaching 2.25" aloft. NEXRAD logged no point detections over Waterloo this day. At 2.25" — tennis ball — this is severe, roof-replacing hail: close to every roof inside the footprint becomes a claim candidate.
Largest hailstone
2.25"
≈ tennis ball · radar-estimated size aloft Homes in the hail footprint
9,204
Ground reports
7
7 hailThe most severe storm Waterloo has seen in the last 12 months
Storm severity score
Overview's storm severity score weighs hailstone size, homes in the footprint, and ground-truth reports.
6.9 /10
- Hail size
- 56 /100
- Homes exposed
- 79 /100
- Ground truth
- 100 /100
Largest hailstone — the top predictor of roof damage.
How many homes sit inside the storm's footprint.
Independent storm reports filed with the NWS.
How Waterloo saw the hail — from two instruments
Two instruments, one storm: NEXRAD logs the point signatures it detected overhead, while the estimated-size surface models how large the hail aloft could have grown. Agreement between them is not guaranteed — the gaps are where the model ran ahead of, or behind, the detections.
Radar-estimated hail size
Radar-estimated maximum hail size across the swath, modeled from radar aloft. It reflects the biggest stone the storm could support, which may differ from what actually fell.
Max size
2.25"
Only the radar-estimated size surface resolved for Apr 14, 2026 — this storm produced no NEXRAD point detections over Waterloo, so there is one map to show, not two.
Where Apr 14, 2026 sits in Waterloo's hail record
This was Waterloo's 1st recorded hail day — the first hail day in our records for the city. By severity it ranks 1st of the 4 storms we have logged here. Radar put the day's largest stone over Waterloo at 2.25" — radar-estimated size aloft.
The Apr 14, 2026 convective day was bigger than Waterloo: the same system put hail over 476 other tracked cities, 94 of them in Wisconsin. Nearest: Lake Mills (7 miles south, up to 2.25"); Johnson Creek (9 miles southeast, up to 1.75"); Watertown (10 miles east, up to 1.75").
These maps are stills from Waterloo's Apr 14, 2026 storm. In the Overview app the same surfaces are live — radar updating in real time, radar-estimated hail size as it forms, and NWS spotter reports pinned where they're filed — with a radar replay you can scrub back over any past day.
What people on the ground reported
These are storm reports filed with the National Weather Service and released through the NOAA Storm Prediction Center — public-domain observations from spotters, the public, and NWS surveys. We quote each one exactly as filed.
Hail reports
7 reports Hail size 1.25"
3 NE Deerfield Dane County
“(MKX)”
— NOAA / SPC storm report
Hail size 1"
Waterloo Jefferson County
“Report from mPING: Quarter (1.00 in.). (MKX)”
— NOAA / SPC storm report
Hail size 1"
Waterloo Jefferson County
“Report from mPING: Quarter (1.00 in.). (MKX)”
— NOAA / SPC storm report
Hail size 1.5"
4 NW Lake Mills Jefferson County
“Report from mPING: Ping Pong Ball (1.50 in.). (MKX)”
— NOAA / SPC storm report
Hail size 1"
4 NW Lake Mills Jefferson County
“Report from mPING: Quarter (1.00 in.). (MKX)”
— NOAA / SPC storm report
Hail size 2"
2 S Marshall Dane County
“(MKX)”
— NOAA / SPC storm report
Storm forensics
Read from the arrival times and locations of the NOAA ground reports,
not a radar-measured storm track.
How the storm moved
The storm tracked northeast at roughly 5 mph, based on the timing of ground reports.
Hail was reported over 74 minutes, from to .
Reports came from Deerfield, Lake Mills, and Marshall — beyond Waterloo itself.
What 2.25" hail means for Waterloo roofs
Two-inch-plus hail punctures shingles, breaks skylights and windows, and dents anything soft. In the core of a footprint like this, close to every roof is a candidate for an insurance claim. Speed decides who writes those jobs.
What this storm is worth to a roofer
$110M
Potential roof exposure — 9,204 homes × the ~$12,000 industry-average hail roof claim. Exposure, not confirmed damage.
Illustrative jobs
46 jobs
Illustrative work
~$690K
Claims from this storm can typically be filed until around April 2028 — the window to reach these homeowners while it's still open. Deadlines vary by policy and state.
Track hail over Waterloo on the live map
Radar updates in real time, spotter reports appear on the map as they're filed, and the full Waterloo storm history — this Apr 14, 2026 storm included — sits underneath. When you're ready, draw this storm's footprint and pull highly accurate homeowner contact information for every address inside it.
Highly accurate contact information starting at $0.23 per address — every contact included. Digital leads cost $15–$40. Start with a 7-day free trial — no credit card required. See pricing
Waterloo hail history
← All hail in Waterloo 4 recorded storm days in Waterloo, WI
Other storms in Waterloo
A storm day here is a convective day — it runs from noon to noon
UTC, so late-night hail is grouped with the afternoon storm that
spawned it rather than split across two calendar dates. Ground
reports are public-domain observations from the NOAA Storm
Prediction Center. Radar surfaces are detections and estimates,
not confirmed damage. Last updated Aug 3, 2026.