Blaine County

Every recorded tornado

1. Injuries and deaths are for the tornado’s whole path, which may extend beyond the county. Deaths recorded within Blaine County: 0.
2. Weak tornadoes were under-recorded before Doppler radar coverage became national in the early 1990s, so earlier decades read low. Ratings use the Fujita scale before February 2007 and the Enhanced Fujita scale after.

Storm Prediction Center severe weather database, 1950 to 2025.

Every large fire

1. Large fires mapped by the Monitoring Trends in Burn Severity program since 1984: 1,000 acres or more in the West, 500 or more in the East. Prescribed burns are excluded. Acres here are the part of each perimeter inside this place.

Monitoring Trends in Burn Severity (USGS and U.S. Forest Service), 1984 to 2026.

Smoke overhead

1. A smoke day is a date on which a smoke plume traced by NOAA Hazard Mapping System analysts from satellite imagery covered this place's point (the county's population centre or the city centre). Counts here are of medium or heavy smoke. Since 2018 analysts have often drawn light smoke as one area over most of the continent, so light-smoke counts are not comparable from year to year. The plumes show smoke anywhere in the air above, not air quality at the ground, and smoke hidden by cloud is missed.

NOAA Hazard Mapping System smoke analysis, 2011 to 2026, retrieved October 30, 2026.

Claims by ZIP code

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026. NOAA Storm Events through 2026.

River crests

River gauges

1. Crests are the highest and the recent crests the National Weather Service lists for each river gauge in the county that has a flood stage, not every flood. Flood categories use each gauge's current flood stages; crests from before levees, dams or channel changes may not be comparable. Crests measured on an old datum are left out of the rankings.

NOAA National Water Prediction Service gauge records, retrieved October 30, 2026.

1. The Palmer Drought Severity Index is computed by NOAA each month from the county's average temperature and precipitation, relative to the county's own climate. Zero is normal; -3 or lower is severe drought and -4 or lower extreme drought. It describes the long-term balance of moisture, not water supply or crop losses.

NOAA NCEI nClimDiv county Palmer Drought Severity Index, 1895 to September 2026, issued October 6, 2026.

1. Earthquakes of magnitude 2.5 or more in the USGS Comprehensive Catalog since 1900. Within 50 miles means the epicentre lies within 50 miles of the county boundary (or inside the county).
2. Small earthquakes were under-recorded before the modern seismic networks of the 1970s and are still missed in remote areas, so early decades read low. Magnitudes are as the catalogue reports them and mix scales (moment, local and body-wave).

USGS ANSS Comprehensive Earthquake Catalog, 1900 to present, retrieved October 30, 2026.

Costliest events since 1996

1. May 7, 2024Flood$1.1 million
   National Weather Service narrative

   MT Department of Emergency services reported $1,071,000 in damages to roads and bridges from the combination of rain and snow melt on the Fort Belknap Reservation in Blaine County.

2. Jul 30, 2023Hail$1.0 million
   National Weather Service narrative

   Several photos submitted on social media of large hail in Chinook. Insurance company reported at least 11 vehicle hail damage claims and 5 homeowners claims. Number of claims likely increased since preliminary reports.

3. Apr 10, 2023Flood$1.0 million
   National Weather Service narrative

   Significant flooding occurred along the Milk River across Blaine County. The Rocky Boy SNOTEL station which is the main Milk River basin station peaked later than normal and had over 3.5 times the snow water equivalent that it normally would on April 6 (10.7��� of snow water equivalent versus a normal of 3.0���). When this thick snowpack melted, virtually the entire Milk River system flooded in a matter of days, as a result. The Milk River near Harlem crested at 23.80 feet on April 12, which as of this entry was the seventh highest river level recorded at this site. Roughly 4,000 aces of irrigation land was flooded. Chinook water plant was surrounded by water. Several…

4. Jul 8, 2022Thunderstorm Wind$200,000
   National Weather Service narrative

   Significant damage to a farm occurred. Two grain bins were destroyed, two roofs heavily damaged, barns heavily damaged, a few windows were reported to be blown out.

5. Jul 3, 2000Thunderstorm Wind$100,000
   National Weather Service narrative

   Storage shed destroyed with valuable machinary damaged...machine shop severely damaged.

6. Jul 8, 2002Tornado$50,000
   National Weather Service narrative

   A severe thunderstorm moved across southern Blaine County during the late afternoon hours on the 8th. This storm produced golf ball sized hail, and wind gusts in excess of 100 mph. A tornado developed shortly after 1600 MST. This tornado was short lived, but it did do some crop damage, along with damage to 3 residences. Several barns were destroyed and a few other structures lost roofs. One vehicle suffered major damage.

7. Mar 27, 1997Flood$25,000
   National Weather Service narrative

   Snow melt from southern Canada caused flooding along Battle Creek, east and north of Chonook. 5 county roads were washed out. Damage was estimated at $25,000.

8. Jul 1, 2004Flood, Blaine$5,000
   National Weather Service narrative

   Slow moving thunderstorms over central Blaine county produced very heavy rainfall during the late afternoon and early evening hours of the 1st. The community of Chinook had approximately 2 inches of rain fall in 30 minutes. Similar amounts were reported at Lloyd and Cleveland, communities located 30 miles south of Chinook. The heavy rains flooded steets and basements, washed out corrals and caused local streams and creeks to flow out of their banks.

9. Jun 17, 1996Thunderstorm Wind$500
   National Weather Service narrative

   Strong thunderstorm winds blew a large plate glass window out of a grocery store. Damage to fix the window was estimated at $500.

1. Storm Events records before 1996 cover only tornadoes, thunderstorm wind and hail. Damage figures are as reported by the National Weather Service at the time, not adjusted for inflation.

NOAA NCEI Storm Events Database, 1950 to 2026, issued October 26, 2026.

All-time high

110°FJul 27, 1917

All-time low

−53°FDec 21, 1989

Warmest night

80°FJun 24, 1912

Coldest day

−25°F4 times, most recently Jan 14, 2024

Wettest day

5.50 inSep 24, 1986

Snowiest day

14.0 in3 times, most recently Dec 27, 2003

Hottest year

1963mean 46.9°F

Coldest year

1951mean 37.9°F

Wettest year

192721.55 in

Driest year

20175.22 in

Snowiest season

66.0 in2010-11

Station Chinook (USC00241722), 2,420 ft elevation, 19.5 miles from the population centre. Daily records from 1895 to October 27, 2026; 95.6% of days in the last 30 years are complete. Records at a single station can differ from a city’s official threaded record, which may combine several stations.

NOAA NCEI Global Historical Climatology Network Daily.

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

OpenFEMA Disaster Declarations Summaries, retrieved October 30, 2026. Statewide declarations are not listed.

Neighbouring counties

• Tornadoes NOAA Storm Prediction Center severe weather database, through 2025.
• Tropical cyclones NOAA National Hurricane Center HURDAT2 (Atlantic; Northeast and Central Pacific), through 2025.
• Wildfire USGS/USFS Monitoring Trends in Burn Severity, through 2026.
• Storm events NOAA NCEI Storm Events Database, through 2026.
• Flood insurance OpenFEMA NFIP Redacted Claims v3, refreshed August 4, 2026.
• Declarations OpenFEMA Disaster Declarations Summaries v2, retrieved October 30, 2026.
• Weather records NOAA NCEI Global Historical Climatology Network Daily, station USC00241722.
• River crests NOAA National Weather Service, National Water Prediction Service river gauges, retrieved October 30, 2026.
• Drought NOAA NCEI nClimDiv county Palmer Drought Severity Index, through September 2026.
• Smoke NOAA NESDIS Hazard Mapping System smoke analysis, retrieved October 30, 2026.
• Earthquakes USGS ANSS Comprehensive Earthquake Catalog (ComCat), retrieved October 30, 2026.

Joins, thresholds and known limits are set out in the methodology. Found an error? Report it. Page built October 30, 2026.