County Hazards

Storm events on record through

Sweet Grass County, Montana Storm events, disaster declarations and flood insurance claims on record

This page is a county record of past events and claims. It does not show the flood zone or the risk of an address. For the flood map of an address, use FEMA's address search (opens in a new tab).

NCEI has 214 storm events on record for Sweet Grass County, Montana, from 1950 through 30 Jun 2026.

The newest event on record is a thunderstorm wind event on 13 May 2026.

FEMA has 10 disaster declarations on record for the county from 1964 through 1 Oct 2026. The newest is DR-4902 of 7 Apr 2026.

OpenFEMA has 10 NFIP claims on record for the county from 1978 through 8 Sep 2026. The NFIP paid $326 thousand on the claims of the years that have an amount in the table.

The NWS collects event reports from a variety of sources, which include (but are not limited to): county, state, and federal emergency management officials, local law enforcement officials, SKYWARN spotters, NWS damage surveys, newspaper clipping services, the insurance industry, and the general public, among others.

The National Weather Service reports property and crop damage estimates using available data at the time of event reporting. These values should therefore be considered broad estimates. Damage amounts are not adjusted for inflation.

Zone (NWS Forecast Zone): A zone is a geographic area defined by the NWS for issuing forecasts, watches, and warnings. While zones often align with counties, they can also represent smaller or subdivided areas within a county to account for differences in weather conditions, such as elevation or proximity to water. Larger-scale events—such as heat, cold, drought, and winter storms—are typically recorded by zone.

The words of the agency. Source: NOAA NCEI, Storm Events Database, page "Frequently Asked Questions", copied on .

This is raw, unedited data from FEMA's National Emergency Management Information System (NEMIS) and as such is subject to a small percentage of human error.

The words of the agency. Source: FEMA, OpenFEMA Dataset "Disaster Declarations Summaries - v2", copied on . The page gives: last data refresh 2026-10-01.

It is derived from the National Flood Insurance Program system of record, staged in the program's reporting platform and redacted to protect policy holder personally identifiable information.

The words of the agency. Source: FEMA, OpenFEMA Dataset "NFIP Redacted Claims - v3", copied on . The page gives: last data refresh 2026-09-09.

Dates of the data: NCEI storm events through . OpenFEMA disaster declarations through . NFIP claims through .

Since the last update: no change is on record for Sweet Grass County. The site compares the agency data at each update. Updates of the data

The five hazards

Storm events on record for Sweet Grass County by hazard and period (NCEI, through 30 Jun 2026)
Hazard1950 to 20262000 to 20092010 to 20192020 to 2026Newest event
Hail13037695
Tornado2000
Flood10143
Wind4151517
Winter212100
Other event types10Heat, cold, drought, wildfire, lightning, fog, tropical and other types
All storm events214699025

A hazard name opens the page of that hazard for the county. A hazard has a page from 10 events. The year 2026 has the events through 30 Jun 2026 only.

Forecast zones with the name of the county give 22 of the 214 events. A county count has the events that NCEI gives to the county. It also has the events of a forecast zone that has the name of the county. A zone with another name counts for the state only.

Rates of Sweet Grass County beside the total of the counties of Montana and of the United States
MeasureSweet GrassAll counties of MontanaAll counties of the United States
Storm events for each 100 square miles, 1950 to 202611.516.749.3
Storm events for each 10,000 residents, 1950 to 2026no figure220.752.5
NFIP claims for each 1,000 policies in force, 2016 to 2025no figure100.0185.3

The columns for the state and the United States total the counties. They count the events of each county in the same way as the county column. The site gives a rate for each 10,000 residents only from 10,000 residents. Residents and area: Census Bureau, 2021.

Newest storm events on record

Thunderstorm Wind69 mph (60 knots, measured gust)

4 miles SSE of BIG TIMBER ARPT

Thunderstorm Wind58 mph (50 knots, measured gust)

13 miles ESE of MC LEOD

Thunderstorm Wind62 mph (54 knots, measured gust)

3 miles NE of MELVILLE

Thunderstorm Wind67 mph (58 knots, measured gust)

At BIG TIMBER ARPT

Thunderstorm Wind59 mph (51 knots, measured gust)

1 mile N of BIG TIMBER

Hail1.00 in, quarter size

At BIG TIMBER

Hail1.25 in, half dollar size

22 miles E of MELVILLE

Thunderstorm Wind60 mph (52 knots, measured gust)

At BIG TIMBER ARPT

Thunderstorm Wind62 mph (54 knots, measured gust)

At BIG TIMBER ARPT

Thunderstorm Wind63 mph (55 knots, measured gust)

1 mile N of BIG TIMBER ARPT

Thunderstorm Wind59 mph (51 knots, measured gust)

9 miles SE of MELVILLE

Flash Flood

10 miles NE of GREYCLIFF

Flash Flood

5 miles N of GREYCLIFF

Thunderstorm Wind62 mph (54 knots, measured gust)

1 mile NW of BIG TIMBER

Thunderstorm Wind59 mph (51 knots, measured gust)

1 mile N of BIG TIMBER ARPT

Hail1.00 in, quarter size

6 miles N of BIG TIMBER

Flood

1 mile NW of BIG TIMBER

Thunderstorm Wind63 mph (55 knots, measured gust)

1 mile N of BIG TIMBER ARPT

Thunderstorm Wind58 mph (50 knots, measured gust)

9 miles SE of MELVILLE

Thunderstorm Wind60 mph (52 knots, measured gust)

1 mile N of BIG TIMBER ARPT

Thunderstorm Wind61 mph (53 knots, measured gust)

1 mile N of BIG TIMBER ARPT

Thunderstorm Wind59 mph (51 knots, measured gust)

11 miles ESE of GREYCLIFF

Thunderstorm Wind59 mph (51 knots, measured gust)

1 mile N of BIG TIMBER ARPT

Hail0.75 in, penny size

3 miles WNW of GREYCLIFF

Hail0.75 in, penny size

10 miles ENE of MELVILLE

The 25 events above are the newest in the NCEI record. A place is the text of the NCEI record: a distance and a direction from a reference place. Wind speed is in miles per hour, with the knots that NCEI gives. The site does not show a place text that names a private property or reads as a person. Download these events (CSV)

Storm events on record for Sweet Grass County by year, 1950 to 2026
DecadeYear that ends in 0Year that ends in 1Year that ends in 2Year that ends in 3Year that ends in 4Year that ends in 5Year that ends in 6Year that ends in 7Year that ends in 8Year that ends in 9All
1950s00000110002
1960s00000100001
1970s00010000001
1980s01001010104
1990s121014264122
2000s33914685152469
2010s2113026705061290
2020s5343334 (part of the year)25

A darker cell has a larger count. The number is in each cell.

NCEI recorded tornado events from 1950, and hail and thunderstorm wind events from 1955. It recorded all event types from 1996. A count before 1996 has fewer event types.

FEMA disaster declarations

FEMA has 10 disaster declarations on record for Sweet Grass County from 1964 through 1 Oct 2026. The newest is DR-4902: SEVERE WINTER STORM AND STRAIGHT-LINE WINDS.

Disaster declarations that name Sweet Grass County (OpenFEMA, through 1 Oct 2026)
DeclaredNumberTypeIncident typeTitle in the FEMA recordAssistance
DR-4902Major disasterStraight-Line WindsSEVERE WINTER STORM AND STRAIGHT-LINE WINDSPublic
DR-4655Major disasterFloodSEVERE STORM AND FLOODINGPublic
DR-4508Major disasterBiologicalCOVID-19 PANDEMICIndividual, Public
EM-3476EmergencyBiologicalCOVID-19Public
DR-1996Major disasterSevere StormSEVERE STORMS AND FLOODINGIndividual, Public
FM-2671Fire management assistanceFireDERBY FIREPublic
EM-3253EmergencyHurricaneHURRICANE KATRINA EVACUATIONPublic
FM-2488Fire management assistanceFireMT-HOBBLE FIRE-08/07/2003Public
DR-1340Major disasterFireWILDFIRESIndividual
DR-1183Major disasterSevere StormSEVERE STORMS,ICE JAMS, SNOW MELT, FLOODINGPublic

DR is a major disaster declaration. EM is an emergency declaration. FM is a fire management assistance declaration. A declaration for the whole state is on the Montana page. What a disaster declaration is

The dataset includes declared recovery programs and geographic areas (county not available before 1964; Fire Management records are considered partial due to historical nature of the dataset).

The words of the agency. Source: FEMA, OpenFEMA Dataset "Disaster Declarations Summaries - v2", copied on . The page gives: last data refresh 2026-10-01.

Flood insurance claims (NFIP)

OpenFEMA has 10 NFIP claims on record for Sweet Grass County from 1978 through 8 Sep 2026.

The NFIP paid $325,998 on 7 claims in the years that have an amount in the table.

FEMA counts 14 residential policies in force on 3 Aug 2026. The site gives a rate for each 1,000 policies only from 100 policies, because one claim changes a smaller rate too much.

NFIP claims in Sweet Grass County by year of loss, 1978 to 2026
DecadeYear that ends in 0Year that ends in 1Year that ends in 2Year that ends in 3Year that ends in 4Year that ends in 5Year that ends in 6Year that ends in 7Year that ends in 8Year that ends in 9All
1970s000
1980s00000000000
1990s00000007007
2000s00000000000
2010s01000000102
2020s0010000 (part of the year)1

A darker cell has a larger count. The number is in each cell.

NFIP claims by year of loss with the amount paid: 4 years
NFIP claims in Sweet Grass County by year of loss, with the amount paid (OpenFEMA, through 8 Sep 2026)
Year of lossClaimsClaims with a paymentAmount paid
20221not shownnot shown
20181not shownnot shown
20111not shownnot shown
199777$325,998

A year with fewer than 5 claims shows the count of claims and no amount. A year with 1 to 4 claims with a payment shows no amount either. Such an amount could point to one property. The amount is the sum of the building, contents and increased cost of compliance payments. How FEMA redacts NFIP claims

This dataset is not intended to be an official federal report, and should not be considered an official federal report.

Note, the County Code field may not reflect the individual county the property is located as projects can be associated with more than one county

The words of the agency. Source: FEMA, OpenFEMA Dataset "NFIP Redacted Claims - v3", copied on . The page gives: last data refresh 2026-09-09.

FEMA cannot verify the quality and/or timeliness of any data or any analysis derived therefrom after the data has been retrieved from FEMA.gov.

The words of the agency. Source: FEMA, OpenFEMA Terms and Conditions, copied on . The page gives: last updated 2025-01-22.

National Risk Index

Risk Index rating
Very Low
Risk Index score
8.1 of 100
Expected Annual Loss rating
Very Low
Expected Annual Loss
$5.9 million
Social Vulnerability rating
Very Low
Community Resilience rating
Relatively Moderate
National Risk Index of Sweet Grass County by hazard type (FEMA, December 2025 release)
Hazard typeRisk Index ratingExpected Annual Loss
AvalancheVery Low$2,236
Cold waveRelatively Low$577,849
DroughtVery Low$3,512
EarthquakeVery Low$156,824
HailVery Low$108,911
Heat waveVery Low$12,622
Ice stormVery Low$2,311
Inland floodingVery Low$3,395,280
LandslideVery Low$2,980
LightningVery Low$87,560
Strong windVery Low$25,361
TornadoVery Low$16,491
WildfireRelatively Low$1,454,520
Winter weatherRelatively Low$46,400

The National Risk Index dataset leverages available source data for natural hazard and community risk factors to develop a baseline relative risk measurement for each United States county and Census tract.

The rating is a qualitative categorization that describes the community in comparison to all other communities at the same level, ranging from “Very Low” to “Very High.”

The National Risk Index data are meant for planning purposes only.

The words of the agency. Source: FEMA, National Risk Index Data: Frequently Asked Questions (December 2025, v1.20), copied on .

The labels and the ratings are those of FEMA. Expected Annual Loss is a figure for a whole county. It is not a figure for a property. How to read the National Risk Index

Tropical storm and hurricane tracks

The HURDAT2 record of the National Hurricane Center goes through the 2025 season. It has no track at tropical storm strength within 100 miles of the centre point of Sweet Grass County.

ZIP Codes, cities and towns of Sweet Grass County

Each ZIP Code below has a page with its NFIP claims by year. 1 more ZIP Code has fewer than 5 claims and no page.

A city or town has no page of its own. This page is the record for the whole county, which has these places:

  • Big Timber
  • Greycliff

Official channels

These links open the pages of the agencies. The site checked the links on .

Cite this page

County Hazards. "Sweet Grass County, Montana: storm events, disaster declarations and flood insurance claims on record". https://countyhazards.com/county/mt/sweet-grass/. Data: NOAA NCEI Storm Events Database through 30 Jun 2026; FEMA OpenFEMA disaster declarations through 1 Oct 2026; FEMA OpenFEMA NFIP claims through 8 Sep 2026. Page made on .

Where the data comes from

  • Storm events: NOAA NCEI Storm Events Database, yearly details files through 30 Jun 2026.
  • Disaster declarations: OpenFEMA Disaster Declarations Summaries, read on 1 Oct 2026.
  • NFIP claims: OpenFEMA NFIP Claims, as of 8 Sep 2026. Multiple-loss properties: 2 Aug 2026. Policies in force: 3 Aug 2026.
  • National Risk Index: FEMA, December 2025 release. Storm tracks: NHC HURDAT2 through the 2025 season.
  • Residents, area, places and adjacent counties: US Census Bureau, 2021 vintage.

How the counts are made · Corrections · Hazards in all states: hail, tornado, flood, wind, winter

Questions

How many tornado events are on record for Sweet Grass County?
NCEI has 2 tornado events on record for Sweet Grass County from 1950 through 30 Jun 2026. No event has a rating of EF2 or F2, or a higher rating.
How large is the hail on record for Sweet Grass County?
NCEI has 130 hail events on record from 1955 through 30 Jun 2026. 22 events have a hail size of 1.75 inches or more. NCEI names 1.75 inches a golf ball.
Which month has the most storm events on record for Sweet Grass County?
June has 72 of the 214 storm events on record from 1950 through 30 Jun 2026.
How many NFIP claims are there for each 1,000 policies in force in Sweet Grass County?
FEMA counts 14 residential policies in force on 3 Aug 2026. The site gives a rate for each 1,000 policies only from 100 policies, because one claim changes a smaller rate too much.