Photo: Kenneth C. Zirkel · CC BY-SA 4.0FEMA expects about as much hazard damage per building in Waltham as in the typical U.S. town, mostly from river and rain flooding
On FEMA’s National Risk Index, Waltham gets a B− for hazard risk: lower expected damage per building than 54% of U.S. towns, #230 of 283 in Massachusetts. Most of that expected damage is river and rain flooding (79%). Flood insurance has paid 114 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 stands out about Waltham’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Waltham 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 Waltham’s grade
River and rain flooding is 79% of the building damage FEMA expects in Waltham, and Waltham’s rate of river and rain flooding damage is higher than 64% of U.S. census tracts. Ice storms add 2%, at a rate in the top 8% of U.S. census tracts.
B− #230 of 283 in Massachusetts; lower expected damage per building than 54% of U.S. towns (21,298).
Waltham’s residents live in 13 census tracts; FEMA’s figures are combined by where they live.
The typical Massachusetts town has lower expected damage than 76% of U.S. towns; within the state, Waltham has more expected damage per building than 81% of Massachusetts towns.
In dollars, FEMA expects about $16.9M a year in losses across Waltham: $15.4M to buildings, the rest to people and crops.
Does Waltham flood? Yes: 114 flood claims since 1978
Every paid claim on a federal flood insurance policy in Waltham, from FEMA’s records: 4.3 per 1,000 homes, more than 56% of the 13,809 U.S. towns with a flood insurance record.
- The March 2010 nor’easter26 claims · $334K
- Hurricane Ida1 claim · $13K
Waltham isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Middlesex County.13 federal disasters brought FEMA money to Waltham
Disasters that paid out in Waltham itself (aid to households or repair grants to the City of Waltham), newest first, with that year’s flood claims.
- 2018Severe Winter Storm and Snowstorm$659K to the City of Waltham for repairs3 flood claims paid that year
- 2015Severe Winter Storm, Snowstorm, and Flooding$787K to the City of Waltham for repairs1 flood claim paid that year
- 2013Severe Winter Storm, Snowstorm, and Flooding$382K to the City of Waltham for repairs
- 2011Severe Storm and Snowstorm$25K to the City of Waltham for repairs
- 2011Hurricane Irene$28K to the City of Waltham for repairs1 flood claim paid for it, $27K
- 2011Severe Winter Storm and Snowstorm$287K to the City of Waltham for repairs
Show all 13
- 2010Severe Storms and Flooding495 households applied for aid$675K aid approved$183K to the City of Waltham for repairs28 flood claims paid that year
- 2006Severe Storms and Flooding8 households applied for aid$16K aid approved$13K to the City of Waltham for repairs2 flood claims paid that year
- 2005Record And/or Near Record Snow$454K to the City of Waltham for repairs1 flood claim paid that year
- 2004Flooding7 households applied for aid$14K aid approved1 flood claim paid that year
- 2003Snow$399K to the City of Waltham for repairs
- 2003Snow$259K to the City of Waltham for repairs
- 2001Snow$397K to the City of Waltham for repairs24 flood claims paid that year
Middlesex County has had 27 natural disasters declared by the President since 1953, most often winter storms, then hurricanes and tropical storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Waltham after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Waltham archive →Waltham and its neighbors
Waltham is 7th of the 7 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 |
|---|---|---|---|
| Lincoln | A+less damage than 96% | river and rain flooding | 9 |
| Lexington | Aless damage than 86% | river and rain flooding | 32 |
| Weston | A−less damage than 84% | river and rain flooding | 24 |
| Newton | A−less damage than 80% | river and rain flooding | 302 |
| Watertown | B+less damage than 72% | river and rain flooding | 14 |
| Belmont | Bless damage than 62% | river and rain flooding | 18 |
| Waltham | B−less damage than 54% | 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 Waltham 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 Waltham
Is Waltham at risk for natural disasters?
On FEMA’s National Risk Index, Waltham has lower expected damage per building than 54% of U.S. towns: B− for hazard risk, #230 of 283 in Massachusetts. Most of the expected damage is river and rain flooding (79%) and hurricanes (8%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Waltham flood?
Flood insurance has paid 114 claims in Waltham since 1978, $1.6M in all, or 4.3 per 1,000 homes, more than 56% of U.S. towns with a flood insurance record. 14 properties have flooded more than once. The most claims came from March 2010 Nor'easter (26).
Is Waltham 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 Middlesex County, 54% of homes in mapped flood zones carry federal flood insurance, and 1.0% of all homes do.
How much is flood insurance in Waltham?
FEMA’s Community Rating System list shows no discount for Waltham’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 Waltham?
By FEMA money that reached Waltham, Severe Storms and Flooding (2010): 495 households applied for aid, $675K approved, and $183K to the City of Waltham for repairs. By flood claims, March 2010 Nor'easter: 26 paid, $334K.
Is Waltham at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (79%), and Waltham’s rate for it is higher than 64% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Waltham.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Waltham’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.