College Heights Estates Historic District · Photo: Farragutful · CC BY-SA 4.0Less hazard damage per building is expected in Adelphi than in 94% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Adelphi gets an A for hazard risk: lower expected damage per building than 94% of U.S. towns, #181 of 261 in Maryland. Most of that expected damage is river and rain flooding (78%), then hurricanes (11%). Flood insurance has paid 2 claims here since 2011.
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 Adelphi 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
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 Adelphi’s grade
River and rain flooding is 78% of the building damage FEMA expects in Adelphi, and Adelphi’s rate of river and rain flooding damage is lower than 79% of U.S. census tracts. Next is hurricanes at 11% (higher than 72% of U.S. census tracts).
A #181 of 261 in Maryland; lower expected damage per building than 94% of U.S. towns (21,298).
Adelphi’s residents live in 7 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, Adelphi has more expected damage per building than 69% of Maryland towns.
In dollars, FEMA expects about $1.4M a year in losses across Adelphi: $822K to buildings, the rest to people and crops.
Does Adelphi flood? Rarely: 2 flood claims since 2011
Every paid claim on a federal flood insurance policy in Adelphi, from FEMA’s records: 0.4 per 1,000 homes, fewer than 93% of the 13,809 U.S. towns with a flood insurance record.
Adelphi isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Prince George's County.1 federal disaster brought FEMA money to Adelphi
Disasters that paid out in Adelphi itself (aid to households or repair grants to Adelphi), newest first, with that year’s flood claims.
- 2003Hurricane Isabel7 households applied for aid$6K aid approved
Prince George's County has had 15 natural disasters declared by the President since 1953, most often winter storms, then floods. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Adelphi after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Adelphi archive →Adelphi and its neighbors
Adelphi is 4th of the 8 graded towns here, from least expected damage per building to most. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| College Park | A+among the lowest damage | river and rain flooding | 41 |
| Silver Spring | A+less damage than 96% | river and rain flooding | 16 |
| University Park | Aless damage than 94% | river and rain flooding | 3 |
| Adelphi | Aless damage than 94% | river and rain flooding | 2 |
| Hillandale | Aless damage than 94% | river and rain flooding | — |
| Langley Park | A−less damage than 82% | river and rain flooding | 2 |
| Hyattsville | B+less damage than 70% | river and rain flooding | 15 |
| Chillum | B+less damage than 68% | river and rain flooding | 114 |
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 Adelphi 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.
- 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 Adelphi
Is Adelphi at risk for natural disasters?
On FEMA’s National Risk Index, Adelphi has lower expected damage per building than 94% of U.S. towns: A for hazard risk, #181 of 261 in Maryland. Most of the expected damage is river and rain flooding (78%) and hurricanes (11%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Adelphi flood?
Flood insurance has paid 2 claims in Adelphi since 2011, $13K in all, or 0.4 per 1,000 homes, fewer than 93% of U.S. towns with a flood insurance record.
Is Adelphi 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 Prince George's County, 0.9% of all homes carry federal flood insurance.
How much is flood insurance in Adelphi?
FEMA’s Community Rating System list shows no discount for Adelphi’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 Adelphi?
By FEMA money that reached Adelphi, Hurricane Isabel (2003): 7 households applied for aid, $6K approved.
Is Adelphi at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (78%), and Adelphi’s rate for it is lower than 79% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Adelphi.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Adelphi’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.