Enter any address in Cascade County, Montana to see its FEMA flood zone
Flash flooding from intense thunderstorms is a significant flood hazard in Cascade County. Over the last 30 years, NOAA data shows 15 flood events and 15 flash flood events. For example, on July 31, 2025, heavy rainfall over the Great Falls urban area caused flash flooding, with one gauge recording 2.25 inches of rain in an hour. Earlier, on May 17, 2023, spring rains and snowmelt caused Belt Creek to flood near Monarch, impacting Sluice Boxes State Park and surrounding areas.
FEMA data indicates that properties in Zone A have experienced the most National Flood Insurance Program claims, with an average payout of $4,805 and an average water depth of 0.9 feet. Homeowners in Zone A, as well as those in areas prone to flash flooding or located near creeks and streams that have previously flooded, should pay close attention to flood risk.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
19 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Cascade County, Montana has recorded 30 flood-related events since 1996 according to NOAA's Storm Events Database, including 15 flash floods and 15 river or area floods. The county has received 7 federal disaster declarations, 2 of which involved flooding or coastal storms. Enter any address above to check its FEMA flood zone designation.
FEMA Disaster Declarations (1975–2020)
Source: OpenFEMA Disaster Declarations Summaries.
| Declaration | Type | Date |
|---|---|---|
| Covid-19 | Biological | Jan 20, 2020 |
| Covid-19 Pandemic | Biological | Jan 20, 2020 |
| Severe Storms And Flooding | Severe Storm | Apr 4, 2011 |
| Hurricane Katrina Evacuation | Hurricane | Aug 29, 2005 |
| Wildfires | Fire | Jul 13, 2000 |
| Severe Storms & Flooding | Flood | May 27, 1981 |
| Rains, Showmelt, Storms & Flooding | Flood | Jun 28, 1975 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flash Flood | Jul 31, 2025 | 0.00K |
| Flood | May 17, 2023 | 60.00K (2 deaths) |
| Flood | May 6, 2023 | 0.00K |
| Flash Flood | Jun 5, 2023 | 50.00K |
| Flash Flood | Jun 3, 2021 | 0.00K |
| Flood | Jul 23, 2020 | 0.00K |
| Flood | May 27, 2019 | 0.00K |
| Flash Flood | Jun 27, 2019 | 0.00K |
| Flood | Jun 27, 2019 | 0.00K |
| Flash Flood | Aug 21, 2019 | 0.00K |
Flash Flood — Jul 31, 2025
An upper-level shortwave combined with monsoon moisture brought a few severe thunderstorms and localized areas of heavy rainfall to North-Central MT. This resulted in isolated large hail, flooding, and a landspout. A stationary storm developed directly over the Great Falls urban area; this produced heavy rainfall and flash flooding in the city, with one gauge reporting 2.25 inches of rain in an...
Flood — May 17, 2023
Spring rains across the area resulted in additional high elevation snowmelt which led to elevated water levels along many creeks and streams. Belt Creek flooded for a second time this month. Water levels crested at 6.78 feet at the river gauge along Belt Creek near Monarch. Water briefly impacted Sluice Boxes State Park's entrance parking lot and flooded primarily fields and driveways from Slui...
Flood — May 6, 2023
Lingering snowpack in the higher elevations of the Little Belt Mountains began to melt in early May. This melting was accelerated by moderate rainfall. Belt Creek ultimately flooded, impacting areas within the Lewis & Clark National Forest to near the community of Belt. Sluice Boxes State Park's main entrance was flooded with the park ultimately closed for a period of time. Some homes between A...
Flash Flood — Jun 5, 2023
Several rounds of rain and thunderstorms affected much of Montana during the first half of June. Flash flooding occurred across portions of the region, especially across Fergus County as well as the Rocky Mountains. Fergus County was hit exceptionally hard as several days of occasional heavy rain exasperated area creeks and streams. Casino Creek, located south of Lewistown, was washed out in at...
Flash Flood — Jun 3, 2021
Showers and thunderstorms crossed the Continental Divide during the afternoon of June 3 and strengthened as they moved over the plains of North-Central Montana. The storms appear to have peaked in the Great Falls area, where a few trees were damaged and some flash flooding occurred. These storms weekend as they moved eastward.
Source: NOAA National Weather Service Storm Events Database.
Source: OpenFEMA NFIP Individual Claims (2.25M records analyzed).
FEMA assigns flood zone designations to areas in Cascade County, Montana:
AE High Risk — 1% annual chance of flooding. Insurance required.
VE Very High Risk — Coastal flooding with wave action.
X (Shaded) Moderate Risk — 500-year floodplain.
X Low Risk — Outside major floodplains.
Properties in Cascade County, Montana that are in FEMA-designated Special Flood Hazard Areas (zones A and V) with federally backed mortgages are required to carry flood insurance.
Even outside high-risk zones, flood insurance is recommended. From 2014 to 2024, nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area.
Visit FloodSmart.gov to find an agent and get a quote.