More hazard damage per building is expected in San Martin than in 97% of U.S. towns, mostly from earthquakes
On FEMA’s National Risk Index, San Martin gets a D− for hazard risk: higher expected damage per building than 97% of U.S. towns, #661 of 847 in California. Most of that expected damage is earthquakes (52%), then river and rain flooding (42%). Flood insurance has paid 5 claims here since 1983.
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 San Martin faces
Each hazard’s share of the building damage FEMA expects here, and how its rate compares with the rest of the country.
Earthquakes
River and rain flooding
Wildfire
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 San Martin’s grade
Earthquakes are 52% of the building damage FEMA expects in San Martin, and San Martin’s rate of earthquakes damage is in the top 2% of U.S. census tracts. Wildfire adds 6%, at a rate in the top 4% of U.S. census tracts.
D− #661 of 847 in California; higher expected damage per building than 97% of U.S. towns (21,298).
San Martin’s residents live in 4 census tracts; FEMA’s figures are combined by where they live.
The typical California town has higher expected damage than 92% of U.S. towns; within the state, San Martin has more expected damage per building than 78% of California towns.
In dollars, FEMA expects about $10.3M a year in losses across San Martin: $8.3M to buildings, the rest to people and crops.
Does San Martin flood? Rarely: 5 flood claims since 1983
Every paid claim on a federal flood insurance policy in San Martin, from FEMA’s records: 2.4 per 1,000 homes, fewer than 57% of the 13,809 U.S. towns with a flood insurance record.
San Martin isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Santa Clara County.The storms San Martin remembers
None of the 19 disasters declared for Santa Clara County shows FEMA aid or repair money reaching San Martin itself in FEMA’s records, so these are its biggest flood-claim years.
- 19831 flood claims paidThe year of Coastal Storms, Floods, Slides and Tornadoes, declared for Santa Clara County
- 19861 flood claims paidThe year of Severe Storms and Flooding, declared for Santa Clara County
- 19951 flood claims paidThe year of Severe Winter Storms, Flooding Landslides, Mud Flow, declared for Santa Clara County
Santa Clara County has had 19 natural disasters declared by the President since 1953, most often severe storms, then floods. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Also 3 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in Santa Clara County, 2002–2020.
Old photos of San Martin after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the San Martin archive →San Martin and its neighbors
San Martin is 2nd of the 2 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 |
|---|---|---|---|
| Morgan Hill | Dmore damage than 95% | river and rain flooding | 51 |
| San Martin | D−more damage than 97% | earthquakes | 5 |
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 San Martin faces
A short kit for the hazards that drive the building damage here, what to check before you buy, and where neighbors get alerts.
- Drop, cover and hold on.
- Strap tall furniture and the water heater to the wall.
- Know how to shut off the gas.
- 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.
- Clear dead leaves and brush within 5 feet of the house.
- Sign up for local alerts and know two ways out.
- Keep N95 masks for smoky days.
- 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 San Martin
Is San Martin at risk for natural disasters?
On FEMA’s National Risk Index, San Martin has higher expected damage per building than 97% of U.S. towns: D− for hazard risk, #661 of 847 in California. Most of the expected damage is earthquakes (52%) and river and rain flooding (42%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does San Martin flood?
Flood insurance has paid 5 claims in San Martin since 1983, $57K in all, or 2.4 per 1,000 homes, fewer than 57% of U.S. towns with a flood insurance record.
Is San Martin 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 Santa Clara County, 22% of homes in mapped flood zones carry federal flood insurance, and 1.7% of all homes do.
How much is flood insurance in San Martin?
FEMA’s Community Rating System list shows no discount for San Martin’s flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
Is San Martin at risk from earthquakes?
It is the largest share of the building damage FEMA expects here (52%), and San Martin’s rate for it is in the top 2% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in San Martin.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where San Martin’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.