776 flood insurance claims·$4.8M paid·5 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 Montgomery County, Maryland. 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 from severe summer thunderstorms dominates Montgomery County's flood profile. Over the last 30 years, the NOAA Storm Events Database recorded 242 flash flood events resulting in 3 deaths, alongside 186 general flood events and 1 tropical storm. Recent high-impact events include a May 2025 flood caused by a slow-moving upper-level low that produced rain rates exceeding two inches an hour and localized totals of four to eight inches in six hours. Another significant event occurred in July 2025, when a slow-moving cold front combined with tropical moisture to produce training thunderstorms and localized rainfall amounts up to six inches.
National Flood Insurance Program records show claims distributed across multiple zones. Zone X leads with 457 claims, averaging a payout of $12,064 and an average recorded water depth of 20 inches. Zone A accounts for 182 claims, with an average payout of $6,728 and an average recorded water depth of 7 inches. Zone X_UNSHADED recorded 63 claims averaging an $18,325 payout with an average water depth of 2 inches. Zone UNKNOWN recorded 50 claims averaging an $8,892 payout with a 1-inch average water depth, while Zone X_SHADED saw 14 claims averaging $5,650 with a 7-inch average water depth. Homeowners and real estate agents in Zone X and Zone A should pay the most attention, given the high concentration of historical insurance claims and recorded water depths in these areas.
Summary written from NOAA storm reports and NFIP claims for this county. Not a prediction.
29% of Montgomery County’s flood insurance claims were on properties rated outside FEMA’s high-risk zones.
268 NFIP claims with a recorded rated flood zone, 1978 to date. The zone is the one FEMA used to rate that policy, which may not match today’s map. Source: OpenFEMA NFIP claims.
In flood insurance claims here that reported a flood depth, the average was 13 inches.
Drawn to scale against an 80-inch door. Even a few inches soaks flooring, the bottom of the drywall and anything plugged in near the floor.
Average of the depths reported on claims (zero and implausible values left out); FEMA’s record doesn’t say exactly where each depth was measured. Source: OpenFEMA NFIP claims.
The worst year was 1996, with 103 claims and $694,019 paid.
Bar height is scaled by square root so ordinary years stay visible next to the worst one. NFIP claims by year of loss. Source: OpenFEMA.
131 NOAA storm reports from Montgomery County describe what happened, in the words of the forecasters who covered it. Read the Maryland flood stories →
21 federal disaster declarations since 1971, 5 of them floods, coastal storms or hurricanes.
| Disaster | Began |
|---|---|
| Severe Winter Storm | Jan 23, 2026 |
| Severe Winter Storm And Snowstorm | Jan 22, 2016 |
| Hurricane Sandy | Oct 26, 2012 |
| Severe Storms And Straight-line Winds | Jun 29, 2012 |
| Hurricane Irene | Aug 26, 2011 |
| Severe Winter Storms And Snowstorms | Feb 5, 2010 |
| Severe Winter Storm And Snowstorm | Dec 18, 2009 |
| Severe Storms, Flooding, And Tornadoes | Jun 22, 2006 |
Weather and water disasters only; most recent first. Source: OpenFEMA Disaster Declarations.
429 since 1996: 242 flash floods and 186 river or area floods.
| Event | Date | Damage |
|---|---|---|
| Flash Flood | Jul 31, 2025 | — |
| Flash Flood | Jul 19, 2025 | — |
| Flash Flood | Jun 18, 2025 | — |
| Flood | May 15, 2025 | — |
| Flood | May 14, 2025 | — |
| Flash Flood | Jul 14, 2025 | — |
| Flash Flood | Jul 12, 2025 | — |
| Flood | Jul 1, 2025 | — |
— = no damage estimate in the record. Source: NOAA Storm Events Database.
Flash Flood · Jul 31, 2025. A slow moving cold front combined with a highly unstable atmosphere along with tropical moisture to produce slow moving thunderstorms with heavy rainfall. Some of these storms trained over the same areas, resulting in scattered to numerous instances of flash flooding. Total rainfall amounts in areas with flash flooding averaged two to four inches, though some localized amounts up to six inches were observed.
Flash Flood · Jul 19, 2025. An unstable atmosphere along with plenty of moisture led to the development of showers and thunderstorms. The thunderstorms were slow moving, and trained over the same areas in spots resulting in flash flooding. Localized rainfall totals of 2 to 4 inches were observed, with upwards of 5 inches in the most persistent thunderstorms.
Flash Flood · Jun 18, 2025. Multiple rounds of slow-moving showers and thunderstorms developed along a weak frontal boundary. These storms produced locally heavy rainfall from Montgomery County to Anne Arundel County. Rainfall amounts of two to four inches were observed with several hours.
Flood · May 15, 2025. A slow moving closed upper level low originating from the Gulf of America brought anomalous moisture into the area. A long duration period of rain ensued, with rain rates exceeding two inches an hour during the afternoon of May 13th. The slow moving storms coupled with training led to localized rainfall totals of four to eight inches across western Maryland, with lesser amounts of two to four inches across central…
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 Montgomery 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.