April 17, 2026 Storm Near Janesville, WI: Reported Hail Sizes

On April 17, 2026, storm reports placed hail up to 2.25 in. within 25 miles of Janesville, Wisconsin; the record shows no wind reports there that day. 12 reports meet National Weather Service severe criteria: hail 1.00 in. or larger, or a gust of 58 mph or more.

Hail reports near Janesville on Apr 17, 2026

14 hail reports fall within 25 miles of the Janesville city center on Apr 17, 2026. The closest value meeting NWS severe criteria came from 1 WSW Janesville, 0.9 miles west of Janesville: 1.50 in. hail (ping pong ball size).

  • 2.25 in. hail — 2 NE Lake Summerset, Illinois, 23.4 mi SW — NWS Local Storm Report (Public, NWS office LOT) — meets NWS severe criteria
  • 2.25 in. hail — 1 SE Durand, Illinois, 24 mi SW — NWS Local Storm Report (Public, NWS office LOT) — meets NWS severe criteria
  • 2.00 in. hail (hen egg size) — 3 E Beloit, 10.9 mi S — NWS Local Storm Report (Trained Spotter, NWS office MKX) — meets NWS severe criteria
  • 1.75 in. hail (golf ball size) — Milton, 7.3 mi NE — NWS Local Storm Report (Public, NWS office MKX) — meets NWS severe criteria
  • 1.75 in. hail (golf ball size) — Beloit, 11.4 mi S — NWS Local Storm Report (Broadcast Media, NWS office MKX) — meets NWS severe criteria
  • 1.75 in. hail (golf ball size) — 4 NE Durand, Illinois, 19.6 mi SW — NWS Local Storm Report (Public, NWS office LOT) — meets NWS severe criteria
  • 1.75 in. hail (golf ball size) — 1 S Durand, Illinois, 24.4 mi SW — NWS Local Storm Report (Public, NWS office LOT) — meets NWS severe criteria
  • 1.50 in. hail (ping pong ball size) — 1 WSW Janesville, 0.9 mi W — NWS Local Storm Report (Public, NWS office MKX) — meets NWS severe criteria
  • 1.50 in. hail (ping pong ball size) — South Beloit, Illinois, 13.5 mi S — NWS Local Storm Report (Public, NWS office LOT) — meets NWS severe criteria
  • 1.25 in. hail (half dollar size) — South Beloit, Illinois, 13.5 mi S — NWS Local Storm Report (Public, NWS office LOT) — meets NWS severe criteria
  • 1.00 in. hail (quarter size) — 3 NNW Footville, 11.6 mi W — NWS Local Storm Report (Trained Spotter, NWS office MKX) — meets NWS severe criteria
  • 1.00 in. hail (quarter size) — 3 W Rockton, Illinois, 16.4 mi S — NWS Local Storm Report (Public, NWS office LOT) — meets NWS severe criteria
  • 0.75 in. hail (penny size) — 3 E South Beloit, Illinois, 13.5 mi S — NWS Local Storm Report (Public, NWS office LOT)
  • 0.50 in. hail — South Beloit, Illinois, 13.5 mi S — NWS Local Storm Report (Public, NWS office LOT)

Measured station gusts near Janesville

No airport weather station (ASOS/AWOS) within 25 miles of Janesville logged a gust of 50 mph or more on April 17, 2026. The record near Janesville that day is driven by hail reports.

What the Apr 17, 2026 numbers mean

The National Weather Service defines a severe thunderstorm as one that produces hail at least 1 inch in diameter, winds of at least 58 mph, or a tornado (NWS glossary). The same 58 mph gust mark triggers an NWS High Wind Warning for wind outside thunderstorms. The largest hail reported near Janesville that day, 2.25 in., meets the NWS hail criterion.

StormAuditor also uses lower screening thresholds — hail 0.75 in. and wind 45 mph — to flag dates worth researching at an address. Screening thresholds are not NWS severe criteria. Hail sizes compare to everyday objects in the Hail Size Guide; gust speeds are explained in the Wind Speed Guide.

Check your Janesville address for Apr 17, 2026

Storm reports are points on a map; a property sits somewhere between them. Run the Free Report Snapshot for any Janesville address: a free YES/NO on whether the public record shows estimated wind of 45 mph or more or hail of 0.75 in. or larger at the property itself. Those are StormAuditor screening thresholds.

For the numbers, the Single Weather Report ($2.99) lists the estimated peak gust and estimated maximum hail size for every qualifying storm date at one address, including April 17, 2026 when the estimate there clears the screening thresholds. The Audit Report shows the evidence and arithmetic behind the estimate for a single date.

Other Wisconsin cities with NWS severe reports on Apr 17, 2026

3 other cities in Wisconsin had a report meeting NWS severe criteria within 25 miles the same day:

More storm days near Janesville and in Wisconsin

How these numbers are counted

This page and the Janesville city page share one set of definitions:

  • Reports from another state: The 25-mile circle around Janesville reaches into Illinois. Values marked with that state's name come from there: they count for Janesville but not on the Wisconsin state page, which counts reports inside Wisconsin only.
  • This page (NWS severe): Every NWS hail and wind report within 25 miles of Janesville that day (StormAuditor records reports from hail 0.50 in. and wind 40 mph), plus airport weather-station gusts of 50 mph or more. The page exists because at least one report or station gust met NWS severe criteria (hail 1.00 in.+ or wind 58 mph+), at least two separate observations were logged, and the day ranks among the most significant.
  • Each observation counts once: A storm report that relays an airport weather station's reading (the same station, the same gust and the same time) counts once, as the station reading. Reports merge only when they are copies of one report: the identical report repeated, or the same report arriving through another feed (SPC or NCEI). Different reports from the same spot, such as two hail sizes reported at one place, count separately.
  • Janesville storm-day table: The city page lists storm days: hail 0.75 in.+ or wind 45 mph+ within 25 miles in the last 12 months (StormAuditor screening thresholds; reports and station gusts, never warnings alone). When this date is in that table, it shows the same largest hail and strongest gust as this page; a value below the screening thresholds shows as a dash.
  • Events (12-month counts): The Janesville city page also counts events, which include NWS warnings. Events measure how busy the area was, not whether a storm hit, so they are not compared with the report counts here.

Full method: Methodology and Data Sources.

Sources for this page

Reports come from NWS Local Storm Reports. StormAuditor merges copies of the same report that arrive through more than one feed, counts a storm report that relays an airport station's reading once, as the station reading, measures each distance from the Janesville city center, and compiled this record on October 7, 2026. See Data Sources and Methodology.

Guides for reading this data

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