Enter any address in Granite County, Montana to see its FEMA flood zone
River and stream rises from heavy precipitation and snowmelt are the dominant flood character in Granite County. Recent events include a flood on June 20, 2018, where 1 to 3 inches of rain combined with snowmelt caused significant rises on the Clark Fork River. Another flood event on June 13, 2017, brought similar conditions with widespread heavy rain and snowmelt leading to rapid rises on small streams, particularly around Georgetown Lake and Philipsburg. Flash flooding from monsoon moisture has also occurred, such as on August 9, 2013, near Drummond.
Homeowners in Zone A, which has experienced claims with water depth and payouts, should pay close attention to flood risk. Residents in Zone X_UNSHADED and Zone X_SHADED areas have also had claims, though with no reported payouts and minimal water depth in the provided data. Properties located near rivers and streams are most likely to be affected by these types of flood events.
Summary generated from NOAA storm narratives and NFIP claim data for this county. Not predictive.
2 NOAA storm reports from this county describe what happened, in the words of the meteorologists who were there.
Granite County, Montana has recorded 21 flood-related events since 1996 according to NOAA's Storm Events Database, including 3 flash floods and 18 river or area floods. The county has received 8 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 (1981–2020)
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 |
| Southwestern Zone Two Fire Complex | Fire | Aug 5, 2000 |
| Wildfires | Fire | Jul 13, 2000 |
| Heavy Rains, Landslides & Flooding | Flood | Feb 24, 1986 |
| Severe Storms & Flooding | Flood | May 27, 1981 |
NOAA Storm Events Database (1996–2025)
Source: NOAA National Weather Service Storm Events Database.
| Type | Date | Damage |
|---|---|---|
| Flood | Jun 20, 2018 | 0.00K |
| Flood | Jun 13, 2017 | 50.00K |
| Flash Flood | Aug 9, 2013 | 0.50K |
| Flash Flood | Aug 9, 2013 | 5.00K |
| Flood | Jun 7, 2011 | 0.00K |
| Flash Flood | Aug 5, 2010 | 1.00K |
| Flood | May 10, 2005 | — |
| Flood | Mar 13, 2003 | — |
| Flood | May 1, 1997 | 69K |
| Flood | Jan 25, 1996 | — |
Flood — Jun 20, 2018
A cut-off low pressure system brought 1 to 3 inches of rain to the upper part of the Clark Fork River Basin resulting in significant stream and river rises. High elevation snow melt also added to the water flow issues.
Flood — Jun 13, 2017
A closed low pressure system brought widespread heavy precipitation amounts of 1-3��� across portions of western Montana. The combination of heavy rain and continued high elevation snow melt caused rapid rises on small streams and creeks, especially around Georgetown Lake, Philipsburg, Drummond, and the Sapphire Mountains.
Flash Flood — Aug 9, 2013
A wave of monsoon moisture tracked south to north across western Montana on August 9, 2013. Embedded multicellular thunderstorms produced very heavy rain with flash flooding reported near Drummond and gusty winds that brought tree damage to portions of the Bitterroot and Missoula Valleys.
Flood — Jun 7, 2011
A mid level circulation over southwest Montana brought widespread heavy rainfall. This same area received significant rainfall the week before. This rainfall in addition to a heavy snow pack had saturated the ground with streams and rivers running high.
Flash Flood — Aug 5, 2010
Severe thunderstorms formed ahead of an approaching upper level trough oriented along the Pacific coast. Thunderstorms mainly produced hail, up to 1.5 inches in diameter, but some wind damage was also reported across southwest Montana. Heavy rain was also reported with these thunderstorms. In some cases nearly an inch of rain fell in a short amount of time. A flash flood occurred in Drummon...
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 Granite 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 Granite 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.