Mason City, IA

Local storm history & FEMA National Risk Index data

Population: 26,948 · Part of Cerro Gordo County

Mason City is rated Relatively Low for overall natural hazard risk — lower risk than most US counties — based on FEMA's National Risk Index for Cerro Gordo County, IA. The county's highest-rated hazards are drought, tornado, and winter weather.

Storm events near Mason City

NOAA-recorded tornado, hail, and flood events within 25 miles of Mason City's center, 2016–2026 — the only hazards NOAA reports with exact coordinates, so these counts are specific to Mason City itself, not the whole county.

Tornado 27 events
Hail 124 events
Inland Flooding 59 events

County-wide hazard risk

Every other hazard FEMA and NOAA track — including drought — is only scored at the county level. These are Cerro Gordo County's FEMA National Risk Index scores, covering Mason City along with the rest of the county, not a Mason City-specific figure.

Hazard NRI score Rating
Wildfire 26.7 Very Low
Inland Flooding 69 Relatively Low
Coastal Flooding Not Applicable
Earthquake 24.2 Very Low
Heat Wave 19.9 Very Low
Tornado 89.3 Relatively Moderate
Avalanche Not Applicable
Cold Wave 74.5 Relatively Moderate
Drought 97.6 Relatively High
Hail 76.1 Relatively Moderate
Hurricane 11.5 Very Low
Ice Storm 42.1 Relatively Low
Landslide 34.3 Very Low
Lightning 21 Very Low
Strong Wind 70.1 Relatively Moderate
Tsunami Not Applicable
Volcanic Activity Not Applicable
Winter Weather 88.1 Relatively High

Source: FEMA National Risk Index v1.20.0, December 2025. See the methodology page for definitions, or the full Cerro Gordo County risk profile for disaster declarations, social vulnerability, and climate projection data.

More on Cerro Gordo County:

Frequently asked questions

What natural hazards is Mason City, IA at risk of?

Mason City is rated Relatively Low for overall natural hazard risk by FEMA's National Risk Index — lower risk than most US counties. The highest-rated hazards for Cerro Gordo County, where Mason City is located, are drought, tornado, and winter weather.

What is Mason City's biggest natural hazard risk?

Drought is the highest-rated hazard for Cerro Gordo County, where Mason City is located, scoring 97.6 out of 100 on FEMA's National Risk Index (rated "Relatively High").

Is Mason City a high-risk area for natural disasters?

No — Mason City carries lower risk than most US counties for overall natural hazard risk, per FEMA's National Risk Index rating of "Relatively Low" for Cerro Gordo County.

Has Mason City had tornadoes, hail, or flooding?

NOAA has recorded 27 tornado, 124 hail, 59 inland flooding events within 25 miles of Mason City since 2016.