2021 Year in Severe Weather
Annual U.S. Storm Report Summary • Published April 10, 2026
Year at a Glance
129,615
Storm Reports
+0.2% vs 2020
7,106
Hail Reports
Largest: 5.5"
52,968
Winter Weather Reports
7,512
Flood / Flash Flood Reports
2021 Highlights:
Snow was the most-reported event with 45,513 reports.
February was the busiest month (22,972 reports).
Colorado led all states with 9,423 reports.
The largest hail recorded measured 5.5 inches in diameter.
Storm Reports by Event Type
| # | Event Type | Reports | % of Total |
|---|
| 1 |
Snow |
45,513 |
35.1% |
| 2 |
Non-Tstm Wnd Gst |
18,642 |
14.4% |
| 3 |
Heavy Rain |
15,932 |
12.3% |
| 4 |
Tstm Wnd Dmg |
12,451 |
9.6% |
| 5 |
Hail |
7,106 |
5.5% |
| 6 |
Tstm Wnd Gst |
5,528 |
4.3% |
| 7 |
Flash Flood |
4,842 |
3.7% |
| 8 |
Heavy Snow |
4,785 |
3.7% |
| 9 |
Flood |
2,343 |
1.8% |
| 10 |
Non-Tstm Wnd Dmg |
2,276 |
1.8% |
| 11 |
Freezing Rain |
1,846 |
1.4% |
| 12 |
Marine Tstm Wind |
1,658 |
1.3% |
Tornado Activity
AL
Most Active State
106 reports
May
Peak Month
263 reports
Top States
| # | State | Reports |
|---|
| 1 | AL | 106 |
| 2 | TX | 91 |
| 3 | IL | 82 |
| 4 | IA | 79 |
| 5 | MS | 76 |
| 6 | TN | 69 |
| 7 | NE | 55 |
| 8 | MO | 54 |
| 9 | KS | 52 |
| 10 | CO | 51 |
Data note: Tornado EF/F intensity ratings are not consistently recorded in storm reports. Counts above represent confirmed tornado reports; intensity data is omitted due to incomplete coverage.
Hail Activity
533
Significant (≥ 2.0")
Baseball size and larger
Top States
| # | State | Reports |
|---|
| 1 | TX | 880 |
| 2 | KS | 555 |
| 3 | WI | 370 |
| 4 | NE | 345 |
| 5 | CO | 306 |
| 6 | MN | 306 |
| 7 | SD | 292 |
| 8 | MO | 259 |
| 9 | MT | 224 |
| 10 | ND | 208 |
Wind Events
39,513
Wind Reports
Damaging & measured gusts
159 mph
Strongest Gust Reported
1,292
Reports ≥ 75 mph
Hurricane-force threshold
By Wind Type
| Type | Reports |
|---|
| Non-Tstm Wnd Gst | 18,642 |
| Tstm Wnd Dmg | 12,451 |
| Tstm Wnd Gst | 5,528 |
| Non-Tstm Wnd Dmg | 2,276 |
| High Sust Winds | 616 |
Top States
| # | State | Reports |
|---|
| 1 | MT | 3,456 |
| 2 | SD | 2,661 |
| 3 | WY | 2,444 |
| 4 | MI | 2,288 |
| 5 | CO | 1,750 |
| 6 | KS | 1,574 |
| 7 | CA | 1,544 |
| 8 | PA | 1,481 |
| 9 | UT | 1,452 |
| 10 | NY | 1,353 |
Winter Weather
52,968
Total Winter Weather Reports
50,298
Snow Reports
Including heavy snow events
By Event Type
| Event | Reports |
|---|
| Snow | 45,513 |
| Heavy Snow | 4,785 |
| Freezing Rain | 1,846 |
| Sleet | 417 |
| Ice Storm | 354 |
| Blizzard | 52 |
| Winter Storm | 1 |
Top States
| # | State | Reports |
|---|
| 1 | CO | 6,290 |
| 2 | NY | 3,115 |
| 3 | MI | 2,764 |
| 4 | MN | 2,702 |
| 5 | WI | 2,563 |
| 6 | MT | 1,959 |
| 7 | IL | 1,949 |
| 8 | WY | 1,848 |
Flood & Flash Flood Reports
7,512
Flood Reports (all types)
By Event Type
| Event | Reports |
|---|
| Flash Flood | 4,842 |
| Flood | 2,343 |
| Coastal Flood | 311 |
| Lakeshore Flood | 16 |
Geographic Distribution — Top States
| # | State | Storm Reports | % of Total |
|---|
| 1 |
CO |
9,423 |
7.3% |
| 2 |
MI |
7,252 |
5.6% |
| 3 |
MT |
6,285 |
4.8% |
| 4 |
NY |
6,110 |
4.7% |
| 5 |
IL |
5,883 |
4.5% |
| 6 |
SD |
5,058 |
3.9% |
| 7 |
WY |
4,581 |
3.5% |
| 8 |
KS |
4,496 |
3.5% |
| 9 |
WI |
4,458 |
3.4% |
| 10 |
PA |
4,186 |
3.2% |
| 11 |
TX |
3,992 |
3.1% |
| 12 |
MN |
3,921 |
3.0% |
| 13 |
NE |
3,405 |
2.6% |
| 14 |
CA |
3,225 |
2.5% |
| 15 |
UT |
2,977 |
2.3% |
| 16 |
VA |
2,892 |
2.2% |
| 17 |
OH |
2,849 |
2.2% |
| 18 |
FL |
2,822 |
2.2% |
| 19 |
IN |
2,673 |
2.1% |
| 20 |
MO |
2,590 |
2.0% |
Monthly Storm Report Activity
| Month |
2021 Reports |
2020 Reports |
Change |
| Jan |
16,274 |
14,562 |
+12%
|
| Feb |
22,972 |
12,977 |
+77%
|
| Mar |
11,022 |
8,819 |
+25%
|
| Apr |
8,076 |
13,470 |
-40%
|
| May |
6,912 |
9,372 |
-26%
|
| Jun |
9,147 |
10,943 |
-16%
|
| Jul |
10,909 |
12,335 |
-12%
|
| Aug |
9,854 |
10,366 |
-5%
|
| Sep |
4,759 |
5,604 |
-15%
|
| Oct |
6,154 |
7,459 |
-17%
|
| Nov |
5,796 |
9,293 |
-38%
|
| Dec |
17,740 |
14,173 |
+25%
|
About This Report
This report summarizes storm spotter reports and NWS weather alerts collected by iAlert for calendar year 2021.
Storm report data is sourced from National Weather Service Local Storm Reports (LSRs) ingested by the iAlert weather monitoring system.
Alert data represents official NWS alerts issued via the NOAA Weather Wire and CAP alert feed.
Data coverage: Contiguous United States, Alaska, Hawaii, and U.S. territories.
Data represents events reported through NWS field offices; actual occurrence may be higher in areas with limited spotter coverage.
Individual storm events may generate multiple LSR entries from different reporting sources, which are counted separately as received from NWS.
Wind gust values reflect reported maximum gusts; entries over 200 mph are excluded as data entry errors.
Hail sizes reflect maximum diameter as reported by spotters and NWS personnel.
