Janesville, WI
Local storm history & FEMA National Risk Index data
Janesville is rated Relatively Moderate for overall natural hazard risk — near the middle compared to other US counties — based on FEMA's National Risk Index for Rock County, WI. The county's highest-rated hazards are hail, tornado, and cold wave.
Storm events near Janesville
NOAA-recorded tornado, hail, and flood events within 25 miles of Janesville's center, 2016–2026 — the only hazards NOAA reports with exact coordinates, so these counts are specific to Janesville itself, not the whole county.
County-wide hazard risk
Every other hazard FEMA and NOAA track — including drought — is only scored at the county level. These are Rock County's FEMA National Risk Index scores, covering Janesville along with the rest of the county, not a Janesville-specific figure.
| Hazard | NRI score | Rating |
|---|---|---|
| Wildfire | 26.8 | Very Low |
| Inland Flooding | 87.6 | Relatively Moderate |
| Coastal Flooding | — | Not Applicable |
| Earthquake | 59.3 | Very Low |
| Heat Wave | 80.8 | Relatively Moderate |
| Tornado | 94.3 | Relatively High |
| Avalanche | — | Not Applicable |
| Cold Wave | 94.1 | Relatively High |
| Drought | 48 | Relatively Low |
| Hail | 95.6 | Relatively High |
| Hurricane | 14.9 | Very Low |
| Ice Storm | 57.9 | Relatively Low |
| Landslide | 60.1 | Very Low |
| Lightning | 84.7 | Relatively High |
| Strong Wind | 86.2 | Relatively High |
| Tsunami | — | Not Applicable |
| Volcanic Activity | — | Not Applicable |
| Winter Weather | 61.2 | Relatively Moderate |
Source: FEMA National Risk Index v1.20.0, December 2025. See the methodology page for definitions, or the full Rock County risk profile for disaster declarations, social vulnerability, and climate projection data.
Other cities in Rock County:
More on Rock County:
Frequently asked questions
What natural hazards is Janesville, WI at risk of?
Janesville is rated Relatively Moderate for overall natural hazard risk by FEMA's National Risk Index — near the middle compared to other US counties. The highest-rated hazards for Rock County, where Janesville is located, are hail, tornado, and cold wave.
What is Janesville's biggest natural hazard risk?
Hail is the highest-rated hazard for Rock County, where Janesville is located, scoring 95.6 out of 100 on FEMA's National Risk Index (rated "Relatively High").
Is Janesville a high-risk area for natural disasters?
Somewhat — Janesville carries near the middle compared to other US counties for overall natural hazard risk, per FEMA's National Risk Index rating of "Relatively Moderate" for Rock County.
Has Janesville had tornadoes, hail, or flooding?
NOAA has recorded 36 tornado, 143 hail, 93 inland flooding events within 25 miles of Janesville since 2016.