Gaithersburg Latitude Observatory · Photo: BobDrzyzgula · Public domainOn FEMA’s figures, few U.S. towns expect less hazard damage per building than Gaithersburg, mostly from river and rain flooding
On FEMA’s National Risk Index, Gaithersburg gets an A+ for hazard risk: among the lowest expected damage per building of U.S. towns, #29 of 261 in Maryland. Most of that expected damage is river and rain flooding (68%), then hurricanes (14%). Flood insurance has paid 6 claims here since 1978.
Graded on FEMA’s expected yearly building damage per dollar of building value (NRI v1.20, December 2025), weighted by where residents live; flood claims are shown, not graded. How hazard risk is graded
What Gaithersburg faces
Each hazard’s share of the building damage FEMA expects here, and how its rate compares with the rest of the country.
River and rain flooding
Hurricanes
Earthquakes
Shares are of FEMA’s expected building damage, the measure the grade uses; ranks compare each hazard’s building-damage rate with all 85,154 U.S. census tracts. In FEMA’s terms, river and rain flooding is FEMA’s “Inland Flooding” (rivers and streams overflowing their banks, or rain overwhelming drainage). FEMA defines coastal flooding as high or rising tides and storm surge, so surge damage is counted there. Drought isn’t listed: FEMA counts its losses in crops only.
What’s behind Gaithersburg’s grade
River and rain flooding is 68% of the building damage FEMA expects in Gaithersburg, and Gaithersburg’s rate of river and rain flooding damage is lower than 95% of U.S. census tracts. Next is hurricanes at 14% (higher than 71% of U.S. census tracts).
A+ #29 of 261 in Maryland; among the lowest expected damage per building of U.S. towns (21,298).
Gaithersburg’s residents live in 26 census tracts; FEMA’s figures are combined by where they live.
The typical Maryland town has lower expected damage than 97% of U.S. towns; within the state, Gaithersburg has less expected damage per building than 89% of Maryland towns.
In dollars, FEMA expects about $6.3M a year in losses across Gaithersburg: $4.4M to buildings, the rest to people and crops.
Does Gaithersburg flood? Rarely: 6 flood claims since 1978
Every paid claim on a federal flood insurance policy in Gaithersburg, from FEMA’s records: 0.2 per 1,000 homes, fewer than 97% of the 13,809 U.S. towns with a flood insurance record.
- Hurricane Isabel1 claim · $1K
Gaithersburg isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Montgomery County.8 federal disasters brought FEMA money to Gaithersburg
Disasters that paid out in Gaithersburg itself (aid to households or repair grants to the City of Gaithersburg), newest first, with that year’s flood claims.
- 2016Severe Winter Storm and Snowstorm$202K to the City of Gaithersburg for repairs
- 2012Hurricane Sandy$27K to the City of Gaithersburg for repairs
- 2011Hurricane Irene$11K to the City of Gaithersburg for repairs
- 2010Severe Winter Storms and Snowstorms$210K to the City of Gaithersburg for repairs
- 2009Severe Winter Storm and Snowstorm$210K to the City of Gaithersburg for repairs
- 2003Hurricane Isabel62 households applied for aid$41K aid approved$62K to the City of Gaithersburg for repairs1 flood claim paid for it, $1K
Show all 8
- 2003Snow$94K to the City of Gaithersburg for repairs
- 2000Severe Winter Storm$41K to the City of Gaithersburg for repairs
Montgomery County has had 17 natural disasters declared by the President since 1953, most often winter storms, then severe storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Gaithersburg after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Gaithersburg archive →Gaithersburg and its neighbors
Gaithersburg has the lowest expected damage per building of the 6 graded towns here. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Gaithersburg | A+among the lowest damage | river and rain flooding | 6 |
| Redland | A+among the lowest damage | river and rain flooding | 3 |
| Montgomery Village | A+less damage than 98% | river and rain flooding | 6 |
| Flower Hill | A+less damage than 97% | river and rain flooding | 1 |
| Darnestown | A+less damage than 96% | river and rain flooding | 4 |
| North Potomac | A+less damage than 96% | river and rain flooding | 6 |
| Washington Grove | — | 577 residents; we grade 1,000+ | |
Hazard risk = FEMA’s expected yearly building damage per dollar of building value, vs. the 21,298 U.S. towns we grade; the map is shaded by fifths of the same scale. Flood claims = paid federal flood insurance claims on record.
Get ready for what Gaithersburg faces
A short kit for the hazards that drive the building damage here, what to check before you buy, and where neighbors get alerts.
- Turn around at flooded roads: a foot of moving water can carry off a car.
- Flood insurance usually takes 30 days to start, so buy it before the forecast.
- Keep papers and medicines up high, in a grab-and-go bag.
- The season runs June through November and peaks from mid-August to mid-October.
- Bring in porch furniture and anything the wind can throw.
- Fill the gas tank and charge phones before the storm arrives.
- Drop, cover and hold on.
- Strap tall furniture and the water heater to the wall.
- Know how to shut off the gas.
- Look up the address on FEMA’s flood map.
- Ask the seller or landlord whether it has ever flooded, and what flood insurance costs there.
- Get a flood insurance quote early: policies usually start 30 days after you buy.
Know where neighbors sign up for alerts? Add it to the Handbook so everyone has it.
Questions about natural hazards in Gaithersburg
Is Gaithersburg at risk for natural disasters?
On FEMA’s National Risk Index, Gaithersburg has among the lowest expected damage per building of U.S. towns: A+ for hazard risk, #29 of 261 in Maryland. Most of the expected damage is river and rain flooding (68%) and hurricanes (14%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Gaithersburg flood?
Flood insurance has paid 6 claims in Gaithersburg since 1978, $8K in all, or 0.2 per 1,000 homes, fewer than 97% of U.S. towns with a flood insurance record. The most claims came from Hurricane Isabel (1).
Is Gaithersburg in a flood zone?
Flood zones are drawn street by street, so the answer depends on the address: look it up on FEMA’s flood map. In Montgomery County, 51% of homes in mapped flood zones carry federal flood insurance, and 0.8% of all homes do.
How much is flood insurance in Gaithersburg?
FEMA’s Community Rating System list shows no discount for Gaithersburg’s flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
What was the biggest storm in Gaithersburg?
By FEMA money that reached Gaithersburg, Severe Winter Storm and Snowstorm (2009): $210K to the City of Gaithersburg for repairs. By flood claims, Hurricane Isabel: 1 paid, $1K.
Is Gaithersburg at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (68%), and Gaithersburg’s rate for it is lower than 95% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Gaithersburg.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Gaithersburg’s residents lived in the 2020 census; OpenFEMA: NFIP redacted claims, multiple-loss properties, community status book and residential penetration rates, housing assistance (owners and renters), public assistance funded projects, hazard mitigation properties and disaster declarations. Homes: Census ACS 2020–24. Preparedness tips: Ready.gov. FEMA’s model is an average of expected damage, not a forecast. How hazard risk is graded.