Cerro Gordo County, Iowa
County storm and disaster record · FIPS 19033 · population 43,117 · 568 sq mi
NOAA's Storm Events Database holds 854 records for Cerro Gordo County, Iowa from 1950 through June 30, 2026, on 515 days; the most frequent are severe thunderstorm wind events (223 records). The deadliest single record is the July 7, 1991 thunderstorm wind: 1 death. FEMA has issued 15 declarations naming the county since 1965, 13 of them for natural hazards; the latest for a natural hazard was “Severe Storms, Tornadoes, Straight-Line Winds, and Flooding” on August 20, 2018.
The record, 1950 to 2026
Storm records filed for the county each year (2026 to June 30, 2026). Before 1996 NOAA recorded only tornadoes (from 1950), thunderstorm wind and hail (from 1955).
- recorded, no damage figure
- under $100,000
- $100,000 or more
- $1 million or more
- $10 million or more, or a death
- $100 million or more, or 10 deaths
- a year's colour: its recorded damage or deaths
- a year with a death
- 1955: wind and hail recorded from 1955
- 1996: all 48 event types from 1996
- Storm records
- 854on 515 days, 1950 to June 30, 2026
- Deaths recorded
- 115 injuries
- Damage, 2025 dollars
- $186Mas filed (scale steps before 1993)
- Tornadoes
- 39strongest F4
- FEMA declarations
- 15latest 2020
Source: NOAA NCEI Storm Events Database, records through June 30, 2026 (file revision 20260918); damage converted to 2025 dollars with the BLS CPI-U. Search the record at NCEI. BLS consumer price index.
What hazards hit Cerro Gordo County most?
The most frequent records are severe thunderstorm wind events: 223 since 1956. 54% of its severe thunderstorm wind events since 1956 fell in June and July. The rank column places the county among Iowa's counties by days with a record per 1,000 square miles of land over each hazard's complete period.
| Hazard | Records | Days | First, last | Killed | Injured | Damage | Rank in state |
|---|---|---|---|---|---|---|---|
| Severe thunderstorm wind | 223 | 134 | 1956-2025 | 1 | 11 | $4.9M | 17 of 99 |
| Hail | 184 | 91 | 1959-2025 | 0 | 0 | $1.9M | 35 of 99 |
| Winter storms | 105 | 102 | 1996-2025 | 0 | 0 | $2.7M | 42 of 99 |
| Floods | 82 | 63 | 1997-2024 | 0 | 0 | $42M | 29 of 99 |
| Heavy rain | 76 | 32 | 2007-2024 | 0 | 0 | – | 20 of 99 |
| High wind and dust storms | 55 | 53 | 1996-2025 | 0 | 1 | $3.2M | 7 of 99 |
| Tornadoes | 39 | 31 | 1953-2025 | 0 | 3 | $16M | 31 of 99 |
| Extreme cold | 38 | 38 | 1996-2025 | 0 | 0 | $9.4M | 13 of 99 |
| Drought | 24 | 24 | 2001-2024 | 0 | 0 | $105M | 62 of 99 |
| Fog, smoke and funnel clouds | 14 | 11 | 1996-2021 | 0 | 0 | – | 32 of 99 |
| Lightning | 10 | 10 | 1997-2019 | 0 | 0 | $241K | 8 of 99 |
| Heat | 4 | 4 | 2001-2019 | 0 | 0 | $177K | 62 of 99 |
Source: NOAA NCEI Storm Events Database (county and forecast-zone records attributed to the county; a zone record shows its own totals on each county it covers). Days: dates with at least one record of the hazard in the county. Ranks: days with a record per 1,000 square miles of land (Census Bureau 2024 Gazetteer), since 1950 for tornadoes, 1955 for hail and thunderstorm wind, 1996 for the rest.
How many tornadoes has Cerro Gordo County had?
NOAA records 39 tornadoes in Cerro Gordo County from 1953 to 2025, the strongest rated F4, with 0 deaths and 3 injuries recorded in the county. That is 31st of 99 Iowa counties by days with tornadoes per 1,000 square miles since 1950. A tornado that crossed a county line is counted in each county it touched, with the length of its path inside the county.
Counted as whole tornadoes rather than county records, the Storm Prediction Center's database holds 40 tornadoes whose track touched Cerro Gordo County since 1950 (NOAA's county records number 39: they file a crossing tornado once per county segment, and the two databases differ on some tracks); along their whole tracks they killed 0 people.
| Date | Tornado | Rating | Path | Killed |
|---|---|---|---|---|
| 1953-05-10 16:10, as SPC files it | Ventura to Fertile | F4 | 26.6 mi | 0 |
| 1967-04-30 17:05, as SPC files it | Clear Lake | F3 | 7.7 mi | 0 |
Map of the strongest tornado tracks in Iowa.
Every tornado record filed for Cerro Gordo County (39)
| Date | Place | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2025-07-28 | Clear Lake, Cerro Gordo County | EF0 1.64 mi x 15 yd | 0 | 0 | – |
| 2022-04-12 | Clear Lake Jct, Cerro Gordo County | EF1 4.49 mi x 100 yd | 0 | 0 | $126K |
| 2021-12-15 | Rock Falls, Cerro Gordo County | EF0 3.54 mi x 60 yd | 0 | 0 | $545 |
| 2021-12-15 | Rockwell, Cerro Gordo County | EF0 2.86 mi x 40 yd | 0 | 0 | $545 |
| 2021-12-15 | Meservey, Cerro Gordo County | EF2 4.93 mi x 100 yd | 0 | 0 | $109K |
| 2021-08-27 | Dougherty, Cerro Gordo County | EFU 2.04 mi x 110 yd | 0 | 0 | $2K |
| 2021-08-27 | Clear Lake, Cerro Gordo County | EF0 2.14 mi x 250 yd | 0 | 0 | $2K |
| 2021-07-14 | Rockwell, Cerro Gordo County | EF0 5.1 mi x 225 yd | 0 | 0 | $13K |
| 2018-06-09 | Clear Lake Lake, Cerro Gordo County | EF0 1.18 mi x 30 yd | 0 | 0 | $235 |
| 2014-06-16 | Freeman, Cerro Gordo County | EF0 1.1 mi x 40 yd | 0 | 0 | $9K |
| 2014-06-16 | Mason City Municipal, Cerro Gordo County | EF1 3.03 mi x 110 yd | 0 | 0 | $74K |
| 2008-06-07 | Mason City Municipal, Cerro Gordo County | EF0 1.01 mi x 40 yd | 0 | 0 | $7K |
| 2005-07-03 | Rock Falls, Cerro Gordo County | F0 0.1 mi x 25 yd | 0 | 0 | $2K |
| 2005-03-30 | Mason City, Cerro Gordo County | F0 1.1 mi x 50 yd | 0 | 0 | – |
| 2005-03-30 | Mason City, Cerro Gordo County | F0 0.5 mi x 40 yd | 0 | 0 | – |
| 2005-03-30 | Mason City, Cerro Gordo County | F0 0.2 mi x 30 yd | 0 | 0 | – |
| 2004-04-17 | Mason City, Cerro Gordo County | F0 0.2 mi x 25 yd | 0 | 0 | – |
| 2003-07-04 | Mason City, Cerro Gordo County | F0 0.1 mi x 20 yd | 0 | 0 | – |
| 2002-06-21 | Rockwell, Cerro Gordo County | F1 5 mi x 40 yd | 0 | 0 | $8K |
| 1999-08-09 | Burchinal, Cerro Gordo County | F0 0.1 mi x 25 yd | 0 | 0 | – |
| 1999-06-06 | Mason City, Cerro Gordo County | F0 0.1 mi x 20 yd | 0 | 0 | – |
| 1998-06-27 | Swaledale, Cerro Gordo County | F2 12.5 mi x 50 yd | 0 | 0 | $244K |
| 1998-06-27 | Thornton, Cerro Gordo County | F2 7.5 mi x 50 yd | 0 | 0 | $94K |
| 1995-06-06 | Mason City Airport, Cerro Gordo County | F1 3.5 mi x 40 yd | 0 | 0 | $149K |
| 1994-07-06 | Portland To, Cerro Gordo County | F1 11.5 mi x 30 yd | 0 | 0 | $110K |
| 1992-05-16 | Cerro Gordo County | F0 0.2 mi x 20 yd | 0 | 0 | $25K step |
| 1990-08-02 | Cerro Gordo County | F1 3 mi x 33 yd | 0 | 0 | $25K step |
| 1988-03-24 | Cerro Gordo County | F1 1 mi x 20 yd | 0 | 0 | $250K step |
| 1984-06-22 | Cerro Gordo County | F1 9 mi x 77 yd | 0 | 0 | $2.5M step |
| 1984-06-16 | Cerro Gordo County | F1 6 mi x 77 yd | 0 | 2 | $250K step |
| 1980-05-30 | Cerro Gordo County | F1 1 mi x 30 yd | 0 | 0 | $25K step |
| 1980-05-29 | Cerro Gordo County | F2 0.5 mi x 30 yd | 0 | 0 | $25K step |
| 1979-08-28 | Cerro Gordo County | F1 1 mi x 60 yd | 0 | 0 | $25K step |
| 1977-02-23 | Cerro Gordo County | F1 0.1 mi x 13 yd | 0 | 1 | $250K step |
| 1973-09-26 | Cerro Gordo County | F2 2 mi x 100 yd | 0 | 0 | $25K step |
| 1967-04-30 | Cerro Gordo County | F3 7.7 mi x 250 yd | 0 | 0 | $250K step |
| 1960-08-28 | Cerro Gordo County | F1 1 mi x 200 yd | 0 | 0 | $3K step |
| 1960-08-28 | Cerro Gordo County | F1 1 mi x 200 yd | 0 | 0 | $3K step |
| 1953-05-10 | Cerro Gordo County | F4 20.2 mi x 33 yd | 0 | 0 | $250K step |
A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.
Source: NOAA NCEI Storm Events Database, tornado records by county (path length in the county, maximum width); ratings as published: F scale before February 1, 2007, EF scale after. Whole-track figures: NOAA Storm Prediction Center tornado database (1950-2025). SPC severe weather database.
When was the last damaging storm in Cerro Gordo County?
The most recent record with damage, injuries or deaths is the July 28, 2025 thunderstorm wind ($50,000 in damage in 2025 dollars).
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2025-09-16 | HailSwaledale, Cerro Gordo County | 1.00 in hail | 0 | 0 | – |
| 2025-08-06 | High WindCerro Gordo County · forecast zone Cerro Gordo | 52 kt wind | 0 | 0 | – |
| 2025-07-28 | Thunderstorm WindVentura, Cerro Gordo County | 61 kt wind | 0 | 0 | $50K |
| 2025-07-28 | Thunderstorm WindVentura, Cerro Gordo County | 56 kt wind | 0 | 0 | $10K |
| 2025-07-28 | TornadoClear Lake, Cerro Gordo County | EF0 1.64 mi x 15 yd | 0 | 0 | – |
| 2025-07-27 | Thunderstorm WindRock Falls, Cerro Gordo County | 58 kt wind | 0 | 0 | $10K |
| 2025-07-27 | Thunderstorm WindMason City, Cerro Gordo County | 62 kt wind | 0 | 0 | $20K |
| 2025-07-27 | Thunderstorm WindMason City Municipal, Cerro Gordo County | 62 kt wind | 0 | 0 | – |
| 2025-06-20 | HailMason City Municipal, Cerro Gordo County | 1.00 in hail | 0 | 0 | – |
| 2025-06-20 | Thunderstorm WindMason City Municipal, Cerro Gordo County | 51 kt wind | 0 | 0 | – |
| 2025-04-28 | HailMason City, Cerro Gordo County | 0.88 in hail | 0 | 0 | – |
| 2025-04-28 | HailVentura, Cerro Gordo County | 1.00 in hail | 0 | 0 | – |
Source: NOAA NCEI Storm Events Database; every record of 2025-2026 is listed, earlier ones when they caused deaths, injuries or $250,000 of damage (2025 dollars), and every tornado.
The deadliest and costliest records
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 1991-07-07 | Thunderstorm WindCerro Gordo County | 1 | 0 | – | |
| 1997-06-15 | Thunderstorm WindClear Lake, Cerro Gordo County Thunderstorms developed to the north of Iowa with the tail of a line of thunderstorms brushing into north central Iowa. As the storms moved into Clear Lake, high winds downed trees across the city. Four injuries were reported due to falling tree debris. | 0 | 4 | $74K | |
| 2007-08-15 | Thunderstorm WindSwaledale, Cerro Gordo County Two semis were blown over between mile markers 185 and 186 on interstate 35. | 61 kt wind | 0 | 2 | $85K |
| 1984-06-16 | TornadoCerro Gordo County | F1 6 mi x 77 yd | 0 | 2 | $250K step |
| 2018-08-28 | Thunderstorm WindThornton, Cerro Gordo County Law enforcement reported a semi-truck blown over by winds on Interstate 35. One individual was transported to the hospital. Time estimated from radar. | 56 kt wind | 0 | 1 | $35K |
| 2003-11-12 | High WindCerro Gordo County · forecast zone Cerro Gordo An intensifying low pressure system moved southeast across southern Minnesota into the lower Great Lakes. As the storm passed Iowa, strong subsidence took place. A tropospheric fold reached below 700 mb in the wake of the storm, enhancing the wind. Strong winds were sustained above 40 MPH for several hours over much ... | 50 kt wind | 0 | 1 | $241K |
| 2003-07-04 | Thunderstorm WindClear Lake, Cerro Gordo County A very unstable air mass was in place over Iowa with surface dew points in the upper 70s to low 80s following a day with highs in the 90s. Lifted indices were in the -10 to -15 C. range as the low level jet began to strengthen during the nighttime hours. A cold front to the northwest of the state began to sink ... | 52 kt wind | 0 | 1 | $8K |
| 1996-08-04 | Thunderstorm WindMason City, Cerro Gordo County Marginal severe thunderstorms moved through the Mason City area. Damage was limited around the city, however there were two injuries caused by downed trees. Both occurred in a similar fashion. A tree fell on top of a car, resulting in one injury. A short time later, a tree fell on top of three cars resulting in ... | 0 | 1 | $47K |
A damage figure marked "step" is a record from before 1993: NOAA then filed damage by category, and the figure is the category as entered, in the dollars of that year, not an estimate of the loss.
| Date | Record | Character | Killed | Injured | Damage |
|---|---|---|---|---|---|
| 2008-06-07 | FloodPortland, Cerro Gordo County | 0 | 0 | $2.1M | |
| 1999-07-19 | Flash FloodMason City, Cerro Gordo County | 0 | 0 | $1.9M | |
| 2018-06-08 | FloodClear Lake Lake, Cerro Gordo County | 0 | 0 | $705K | |
| 2008-06-08 | Flash FloodMason City, Cerro Gordo County | 0 | 0 | $685K | |
| 2014-08-23 | Flash FloodMason City, Cerro Gordo County | 0 | 0 | $623K | |
| 1998-06-23 | Thunderstorm WindClear Lake, Cerro Gordo County | 0 | 0 | $498K | |
| 2007-08-19 | Flash FloodWinnebago Hgts, Cerro Gordo County | 0 | 0 | $391K | |
| 1999-07-02 | FloodCerro Gordo County · forecast zone Cerro Gordo | 0 | 0 | $354K |
Before 1993 NOAA filed damage by category, not amount, so the list above starts in 1993. The highest category filed here before then (entered as $2.5M, in the dollars of the day) holds: June 22, 1984 (tornado, Cerro Gordo County).
Source: NOAA NCEI Storm Events Database: deaths and injuries direct and indirect; damage is property plus crops as estimated by the National Weather Service, converted to 2025 dollars.
Is it getting more frequent?
Records per decade for Cerro Gordo County's most frequent hazards. Counts rose everywhere after 1996, when NOAA began recording every event type, so compare decades within a hazard's complete period only (the shaded cells come before it).
| Hazard | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020-26 |
|---|---|---|---|---|---|---|---|---|
| Severe thunderstorm wind | 2 | 11 | 17 | 12 | 47 | 36 | 68 | 30 |
| Hail | 1 | 4 | 3 | 4 | 19 | 68 | 60 | 25 |
| Winter storms | – | – | – | – | 16 | 32 | 40 | 17 |
| Floods | – | – | – | – | 16 | 33 | 30 | 3 |
| Heavy rain | – | – | – | – | 0 | 1 | 60 | 15 |
| High wind and dust storms | – | – | – | – | 12 | 20 | 13 | 10 |
Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).
What time of year?
54% of its severe thunderstorm wind events since 1956 fell in June and July. The two busiest months are in violet.
The values, month by month
Jan 56 · Feb 37 · Mar 53 · Apr 69 · May 113 · Jun 176 · Jul 121 · Aug 83 · Sep 62 · Oct 32 · Nov 15 · Dec 37 (records).
Source: NOAA NCEI Storm Events Database, records by the month they began.
Federal disaster declarations for Cerro Gordo County
FEMA's register lists 15 declarations that include Cerro Gordo County: 13 major disasters, 2 emergencies and 0 fire management assistance declarations. Most were for flood (6) and severe storm (4).
| Declared | Number | Type | Title |
|---|---|---|---|
| 2020-03-23 | DR-4483 | Biological | Covid-19 Pandemic |
| 2020-03-13 | EM-3480 | Biological | Covid-19 |
| 2018-08-20 | DR-4386 | Severe Storm | Severe Storms, Tornadoes, Straight-Line Winds, and Flooding |
| 2016-10-31 | DR-4289 | Flood | Severe Storms and Flooding |
| 2008-05-27 | DR-1763 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| 2005-09-10 | EM-3239 | Hurricane | Hurricane Katrina Evacuation |
| 2004-05-25 | DR-1518 | Severe Storm | Severe Storms, Tornadoes, and Flooding |
| 1999-07-22 | DR-1282 | Severe Storm | Severe Storms and Flooding |
| 1998-07-02 | DR-1230 | Flood | Severe Storms, Tornadoes and Flooding |
| 1993-07-09 | DR-996 | Flood | Severe Storms & Flooding |
| 1991-12-26 | DR-928 | Severe Ice Storm | Ice Storm |
| 1990-09-06 | DR-879 | Flood | Severe Storms & Flooding |
| 1979-07-01 | DR-590 | Tornado | High Winds & Tornadoes |
| 1969-08-14 | DR-269 | Flood | Heavy Rains & Flooding |
| 1965-04-22 | DR-193 | Flood | Flooding |
Source: FEMA OpenFEMA Disaster Declarations Summaries (v2), declarations through October 2, 2026; one declaration is counted once however many areas it names. OpenFEMA dataset page.
How many floods has Cerro Gordo County had?
NOAA's Storm Events Database holds 82 flood or flash flood records for Cerro Gordo County from 1997 to 2024, on 63 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Cerro Gordo County ranks 895th of 2,942 U.S. counties.
The National Flood Insurance Program has paid $3.5 million on 216 claims filed in Cerro Gordo County; the most in one year was 89 in 2008. Claims count insured losses only: uninsured flood damage is not in this file.
The values, year by year
1978: 4 · 1979: 15 · 1980: 10 · 1981: 3 · 1982: 2 · 1983: 1 · 1984: 13 · 1990: 8 · 1991: 1 · 1993: 2 · 1997: 1 · 1999: 24 · 2001: 1 · 2004: 26 · 2007: 1 · 2008: 89 · 2013: 1 · 2014: 1 · 2016: 2 · 2018: 11; the other years: 0.
Source: FEMA OpenFEMA NFIP Redacted Claims, as of September 8, 2026; claims by year of loss, payments in the dollars of the year paid. OpenFEMA dataset page.
FEMA's modeled risk for Cerro Gordo County
FEMA's National Risk Index rates Cerro Gordo County Relatively Low overall, with an expected annual loss of $27.4 million. These are FEMA's model estimates of future loss from 18 hazards, not a count of what happened; they can differ from the record above.
| Hazard | Risk rating | Expected annual loss | Modeled frequency |
|---|---|---|---|
| Drought | Relatively High | $4.0M | 24 modeled event-days a year |
| Winter Weather | Relatively High | $343K | 20 a year (modeled) |
| Tornado | Relatively Moderate | $6.5M | once in about 2 years (modeled) |
| Hail | Relatively Moderate | $697K | 4.6 a year (modeled) |
| Cold Wave | Relatively Moderate | $2.5M | 11 a year (modeled) |
| Strong Wind | Relatively Moderate | $942K | 3.9 a year (modeled) |
| Riverine Flooding | Relatively Low | $12M | 2.2 a year (modeled) |
| Ice Storm | Relatively Low | $57K | once in about 2 years (modeled) |
Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.
Counties that share a border with Cerro Gordo County
Source: U.S. Census Bureau county adjacency file; NOAA NCEI Storm Events Database, records since 1950. The Census Bureau's adjacency file.
Next
- Tornadoes in IowaEvery Iowa tornado since 1950 and the counties with the most per square mile
- Severe thunderstorm wind in IowaThe state's severe thunderstorm wind events, by county, year and month
- The Iowa recordEvery hazard in the state, its deadliest events and its federal declarations
- FEMA's risk rating for each hazard in Cerro Gordo CountyThe hazard risk calculator: 18 hazards beside the county's record
- Download Cerro Gordo County's FEMA declarations (CSV)15 rows: every declaration that named the county, for your own analysis