Chisago County, Minnesota

What hazards hit Chisago County most?

The most frequent records are severe thunderstorm wind events: 98 since 1965. 63% of its severe thunderstorm wind events since 1965 fell in June and July. The rank column places the county among Minnesota's counties by days with a record per 1,000 square miles of land over each hazard's complete period.

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 Chisago County had?

NOAA records 19 tornadoes in Chisago County from 1954 to 2020, the strongest rated F4, with 0 deaths and 2 injuries recorded in the county. That is 24th of 87 Minnesota 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 20 tornadoes whose track touched Chisago County since 1950 (NOAA's county records number 19: 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.

Map of the strongest tornado tracks in Minnesota.

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 Chisago County?

The most recent record with damage, injuries or deaths is the July 28, 2019 tornado ($577,000 in damage in 2025 dollars).

This is the continuation path of the Washington County tornado that moved into Chisago County on 240th Street North, east of Morgan Avenue. This EF1 tornado continued for approximately another 3.8 miles before dissipating north of a farm that was damaged on 268th Street. Along the path in Chisago County, the tornado damaged a farm shed, uprooted numerous trees, damaged an outdoor wedding venue near Highway 25, and destroyed an outbuilding before dissipating. Maximum winds were estimated at 90 mph, with a width of 250 yards in Chisago County.
National Weather Service event narrative, NOAA Storm Events Database (search the full record, event 835226)

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

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: 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 Chisago 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).

Source: NOAA NCEI Storm Events Database, records per calendar decade; zone records from the CZ_TYPE field (Z).

What time of year?

63% of its severe thunderstorm wind events since 1965 fell in June and July. The two busiest months are in violet.

Source: NOAA NCEI Storm Events Database, records by the month they began.

Federal disaster declarations for Chisago County

FEMA's register lists 12 declarations that include Chisago County: 8 major disasters, 3 emergencies and one fire management assistance declaration. Most were for flood (5) and biological (2).

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 Chisago County had?

NOAA's Storm Events Database holds 6 flood or flash flood records for Chisago County from 1997 to 2005, on 5 days, with 0 deaths. By flood insurance claims since 1978 (OpenFEMA, as of September 8, 2026), Chisago County ranks 1811th of 2,942 U.S. counties.

The National Flood Insurance Program has paid $422,000 on 37 claims filed in Chisago County; the most in one year was 14 in 1986. Claims count insured losses only: uninsured flood damage is not in this file.

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 Chisago County

FEMA's National Risk Index rates Chisago County Relatively Low overall, with an expected annual loss of $22.7 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.

Source: FEMA National Risk Index, county table, December 2025 release. FEMA's National Risk Index map.

Counties that share a border with Chisago County

1. Anoka County 770
2. Washington County 593
3. Pine County 534
4. Polk County, WI 520
5. Burnett County, WI 482
6. Chisago County 364
7. Isanti County 362
8. Kanabec County 314

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 MinnesotaEvery Minnesota tornado since 1950 and the counties with the most per square mile
• Severe thunderstorm wind in MinnesotaThe state's severe thunderstorm wind events, by county, year and month
• The Minnesota recordEvery hazard in the state, its deadliest events and its federal declarations
• FEMA's risk rating for each hazard in Chisago CountyThe hazard risk calculator: 18 hazards beside the county's record
• Download Chisago County's FEMA declarations (CSV)12 rows: every declaration that named the county, for your own analysis