4 federal flood & hurricane disasters
Share of the whole county outline, rivers and lakes included; parts FEMA hasn’t mapped count as zero.
Shaded areas are FEMA’s mapped flood hazard zones in and around Petroleum County, Montana. Zoomed out they are simplified; at street level the map switches to FEMA’s exact layer. Tap anywhere to check that spot, or search an address above.
Petroleum County experiences a flood risk profile dominated by riverine and general flooding, supplemented by localized flash flooding driven by severe weather. Over a thirty-year period, NOAA records show 17 flood events and 7 flash flood events.
These flood hazards frequently develop during the spring and summer months as upper-level lows, mid-level disturbances, and stalled storm tracks generate prolonged moderate to heavy rainfall and severe thunderstorms. For example, a stalled storm track produced prolonged rainfall across southern Petroleum County in May 2019, while a mid-level disturbance brought severe weather and flooding to the area in August 2021. Additional heavy rainfall from an upper-level low caused flash flooding impacts in June 2023, and shortwaves triggered further flooding during severe thunderstorms in July 2022.
Homeowners, real estate agents, and journalists should pay the closest attention to properties situated in low-lying areas, near stream channels, or within designated flood hazard zones where heavy seasonal rainfall and thunderstorms regularly produce standing water and rapid runoff.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
1 NOAA storm reports from Petroleum County describe what happened, in the words of the forecasters who covered it. Read the Montana flood stories →
12 federal disaster declarations since 1986, 4 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Winter Storm And Flooding | May 6, 2024 |
| Flooding | Jun 1, 2023 |
| Flooding | Apr 12, 2018 |
| Lodgepole Fire Complex | Jul 20, 2017 |
| Severe Storms, Straight-line Winds, And Flooding | Aug 21, 2014 |
| Flooding | May 19, 2013 |
| Severe Storms And Flooding | Apr 4, 2011 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
24 since 1996: 7 flash floods and 17 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jun 23, 2023 | — |
| Flood | Jul 4, 2022 | — |
| Flood | Aug 26, 2021 | — |
| Flood | May 27, 2019 | — |
| Flood | Mar 12, 2018 | — |
| Flood | Jun 1, 2018 | — |
| Flood | Oct 4, 2016 | — |
| Flood | Aug 23, 2014 | $515,000 |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Jun 23, 2023. An upper level low moving to the south along the Montana-Wyoming border, generated heavy rainfall across southern parts of northeast Montana, with some flash flooding impacts recorded in Petroleum County.
Flood · Jul 4, 2022. Shortwave moved through the southwesterly flow aloft that's been parked over the area this week and set off another round of severe thunderstorms over the area this afternoon into the overnight hours.
Flood · Aug 26, 2021. A mid-level disturbance moving through the region, combined with favorable winds to generate and support multiple severe thunderstorms in Garfield and Petroleum Counties along with some flooding for Petroleum County.
Flood · May 27, 2019. A stalled storm track prolonged at moderate to heavy rainfall for many hours across most of southern Petroleum County.
National Weather Service narratives, lightly trimmed. Source: NOAA Storm Events Database.
Every colour on the map above is a place on this drawing: where the ground sits relative to the flood FEMA plans for.
If a building in Petroleum County is in a high-risk zone (A or V) and its mortgage comes from a federally regulated or insured lender, or is federally backed, flood insurance is required.
Outside those zones it is optional, and often worth having: from 2014 to 2024 nearly one-third of NFIP claims came from outside the high-risk Special Flood Hazard Area. Since Risk Rating 2.0, NFIP premiums are set for each building, so the only reliable price is a quote: FloodSmart.gov or a local agent.