Accuracy scorecard · updated 2026-10-15

How close is radar hail to what people measured?

Every street on a StormRoute list gets its hail size from NOAA's radar estimate. So we checked that estimate against the ground: every National Weather Service hail report of 1 inch or more in our 44 markets, Oct 2024 – Oct 2026, compared with the same radar grid our morning lists use. Here is what we found, good and bad.

1,374hail reports checked (1 in+)

74%radar showed 1 in+ hail within 3 mi

94%same, for 2 in+ hail

7%radar read more than ½ in too big

Did the radar see the hail?

Share of reports where radar showed hail of 1 inch or more within 3 miles: the same distance as the ground check on every street.

All reports, 1 in+74%

1.00–1.49 in reported67%

1.50–1.99 in reported78%

2 in+ reported94%

Was the size right?

Biggest radar estimate within ¾ mile of the report (the distance a street's hail size uses), against the size people reported.

All reports (1,374 reports)51% close · 42% lower · 7% higher

1.00–1.49 in reported (821 reports)65% close · 27% lower · 8% higher

1.50–1.99 in reported (322 reports)38% close · 55% lower · 6% higher

2 in+ reported (231 reports)22% close · 73% lower · 5% higher

Close: within ½ inRadar more than ½ in lowerRadar more than ½ in higher

What it means for your list

Big hail is real when radar says so.Radar showed 1-inch-plus hail within 3 miles of 94% of the 2-inch-plus reports. The storms that fill roofing schedules are the ones radar catches best.
Radar sizes lean low, not high.Radar read more than half an inch too big on only 7% of reports, and more than half an inch too small on 42%. The typical gap: radar 0.41 inch under what people reported. We print the radar number as it is and never round it up, so a street's hail size is more often an undercount than an overcount.
Radar misses some smaller, scattered hail.For 1.00–1.49 inch reports, radar showed 1-inch hail within 3 miles 67% of the time. That's why every street also shows whether a Weather Service hail report was logged within 3 miles, and says "radar only" when none was.
Two checks before anything is sent.Every morning, two independent checks must pass before a list goes out. If the data can't be verified, members get a "don't canvass" notice instead of a guess.

How we measured, and the limits

Reports: National Weather Service hail reports (Storm Prediction Center, filtered), 1.00 inch or larger, inside each market's 30-mile area, on the 291 storm days in our 2-year archive. Radar: NOAA MRMS MESH, the daily maximum (about 1 km grid) for the same storm day, the grid our lists use. Limits: reports exist only where people saw hail and reported it, so this checks the radar where reports exist and can't count hail nobody reported. Report sizes are usually estimated by eye (coins, golf balls, ruler photos), and people tend to report the biggest stone. Markets with fewer than 20 reports are small samples. Hail sizes on our lists are radar estimates, and a ranked street is a place to inspect, never a promise that a roof is damaged.

Results by market (44 markets)

Market	Reports	Radar saw 1 in+ ≤3 mi	Typical size gap
Kansas City, MO	82	56%	-0.49 in
Oklahoma City, OK	82	67%	-0.57 in
Wichita, KS	82	72%	-0.33 in
Dallas, TX	72	68%	-0.44 in
Fort Worth, TX	71	73%	-0.54 in
St. Louis, MO	61	82%	-0.48 in
Aurora, IL	59	70%	-0.28 in
Omaha, NE	54	85%	-0.35 in
Lubbock, TX	52	96%	-0.29 in
Tulsa, OK	51	71%	-0.27 in
Denver, CO	49	69%	-0.32 in
McKinney, TX	46	80%	-0.41 in
Springfield, MO	44	77%	-0.33 in
Chicago, IL	41	73%	-0.45 in
Madison, WI	41	76%	-0.77 in
Des Moines, IA	36	61%	-0.20 in
Rapid City, SD	36	94%	-0.27 in
Austin, TX	35	89%	-0.09 in
Enid, OK	35	86%	-0.21 in
Lincoln, NE	33	76%	-0.28 in
Colorado Springs, CO	30	80%	-0.27 in
Minneapolis, MN	28	89%	-0.34 in
Lawton, OK	27	70%	-0.57 in
Nashville, TN	27	48%	-0.69 in
Amarillo, TX	26	100%	-0.28 in
Shreveport, LA	23	56%	-0.45 in
Temple-Waco, TX	22	86%	-0.01 in
Huntsville, AL	21	52%	-0.49 in
Fayetteville, AR	19	90%	-0.67 in
Kankakee, IL	19	74%	-0.45 in
Fort Collins, CO	18	89%	+0.01 in
Manchester, NH	18	33%	-0.67 in
Houston, TX	17	82%	-0.13 in
Memphis, TN	16	44%	-0.46 in
San Antonio, TX	14	86%	-0.45 in
Wausau, WI	13	62%	-0.37 in
Charlotte, NC	12	67%	-0.56 in
Little Rock, AR	12	50%	-0.57 in
Rochester, MN	12	67%	-0.42 in
Fox Cities (Appleton–Oshkosh), WI	10	30%	-0.70 in
Gulf Coast (Mobile–Pensacola–Destin), FL	10	100%	-0.28 in
Dothan–Enterprise, AL	7	71%	-0.66 in
Hattiesburg (Pine Belt), MS	5	100%	+0.20 in
Panama City, FL	3	100%	+0.04 in

Typical size gap = median of radar (within ¾ mi) minus reported size; negative means radar read lower.

Every report checked, with both radar numbers: accuracy-rows.json. Totals: accuracy.json.

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