1 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 San Juan County, Utah. 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.
Flash flooding driven by summer thunderstorms dominates the flood profile of San Juan County, Utah. Over the past 30 years, NOAA records document 59 flash flood events and 10 general flood events, resulting in one fatality.
Severe weather events are frequently fueled by monsoonal moisture combined with atmospheric systems that produce heavy rain and slow-moving, training thunderstorms. For example, deep monsoonal moisture and daytime heating triggered localized heavy rain and flash flooding on August 26, 2025. Similarly, anomalous moisture and slow-moving training storms led to flash flooding across the region on June 4, 2025, while tropical and monsoonal moisture drove severe weather and heavy rain on June 21, 2024, and August 10, 2024.
Homeowners, real estate agents, and journalists should pay the closest attention to properties situated in low-lying areas, near arroyos, or along complex terrain where intense afternoon convection and rapid runoff can trigger sudden flash floods.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
16 NOAA storm reports from San Juan County describe what happened, in the words of the forecasters who covered it. Read the Utah flood stories →
6 federal disaster declarations since 1977, 1 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Deer Creek Fire | Jul 10, 2025 |
| Pack Creek Fire | Jun 10, 2021 |
| Hurricane Katrina Evacuation | Aug 29, 2005 |
| Drought | Jan 20, 1977 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
69 since 1996: 59 flash floods and 10 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Aug 26, 2025 | — |
| Flash Flood | Jun 4, 2025 | $50,000 |
| Flash Flood | Jun 21, 2024 | — |
| Flash Flood | Aug 10, 2024 | — |
| Flash Flood | Sep 14, 2023 | $12,000 |
| Flash Flood | Aug 26, 2022 | $500 |
| Flash Flood | Aug 20, 2022 | $250 |
| Flash Flood | Aug 14, 2022 | $5,000 |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Aug 26, 2025. Unusually rich monsoonal moisture was in place on the morning of August 26th, with precipitable water close to 1.00 inch across eastern Utah and western Colorado. A jet streak moving in aloft brought not only additional moisture, but some extra lift as well. In addition, daytime heating on the complex terrain in this region help to spur on afternoon convection. As a result, widespread shower and thunderstorm activ…
Flash Flood · Jun 4, 2025. Anomalously deep moisture was present across southeast Utah and southwest Colorado on the afternoon of June 4th. Enough sunshine had gotten through during the morning hours to create afternoon instability of 500-1000 J/Kg, more than enough to produce some strong storms. In addition, atmospheric profiles favored heavy rain development and slow moving, training thunderstorms. All these factors combined to lead to a…
Flash Flood · Jun 21, 2024. Very deep tropical moisture associated with the remnants of Tropical Storm Alberto combined with monsoonal moisture was forced through eastern Utah and western Colorado due to a large high pressure ridge over the Central U.S. and a deep low pressure trough over the Great Basin. This deep moisture combined with strong instability and shear to produce widespread severe weather across eastern Utah and western Colorad…
Flash Flood · Aug 10, 2024. High pressure over Texas and low pressure over the Baja Coast kept a deep southerly flow of monsoonal moisture across the Four Corners region. Training storms led to significant flash flooding across southeast Utah.
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 San Juan 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.