Sunnyvale’s building-damage rate from hail is in the top 3% of U.S. census tracts
On FEMA’s National Risk Index, Sunnyvale gets a C+ for hazard risk: higher expected damage per building than 58% of U.S. towns, #385 of 642 in Texas. Most of that expected damage is river and rain flooding (60%), then hail (23%). Flood insurance has paid 6 claims here since 1991.
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 Sunnyvale’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Sunnyvale 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
Hail
Tornadoes
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 Sunnyvale’s grade
River and rain flooding is 60% of the building damage FEMA expects in Sunnyvale, and Sunnyvale’s rate of river and rain flooding damage is higher than 52% of U.S. census tracts. Hail adds 23%, at a rate in the top 3% of U.S. census tracts.
C+ #385 of 642 in Texas; higher expected damage per building than 58% of U.S. towns (21,298).
Sunnyvale’s residents live in 4 census tracts; FEMA’s figures are combined by where they live.
The typical Texas town has higher expected damage than 50% of U.S. towns; within the state, Sunnyvale has more expected damage per building than 60% of Texas towns.
In dollars, FEMA expects about $3.7M a year in losses across Sunnyvale: $2.4M to buildings, the rest to people and crops.
Does Sunnyvale flood? Rarely: 6 flood claims since 1991
Every paid claim on a federal flood insurance policy in Sunnyvale, from FEMA’s records: 2.1 per 1,000 homes, fewer than 60% of the 13,809 U.S. towns with a flood insurance record.
Sunnyvale isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Dallas County.2 federal disasters brought FEMA money to Sunnyvale
Disasters that paid out in Sunnyvale itself (aid to households or repair grants to the Town of Sunnyvale), newest first, with that year’s flood claims.
- 2024Severe Storms, Straight-line Winds, Tornadoes, and Flooding62 households applied for aid$46K aid approved$269K to the Town of Sunnyvale for repairs
- 2021Severe Winter Storms99 households applied for aid$25K aid approved
Dallas County has had 22 natural disasters declared by the President since 1953, most often severe storms, then hurricanes and tropical storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Sunnyvale after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Sunnyvale archive →Sunnyvale and its neighbors
Sunnyvale is 2nd of the 4 graded towns here, from least expected damage per building to most. Tap a town to see its hazards.
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 Sunnyvale 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.
- Park in a garage or under cover when storms are forecast.
- Stay away from windows while it falls.
- Photograph roof and car damage for your insurer.
- Pick your spot now: the lowest floor, an inside room, no windows.
- A watch means be ready; a warning means take cover now.
- Keep shoes and a flashlight by the bed.
- 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 Sunnyvale
Is Sunnyvale at risk for natural disasters?
On FEMA’s National Risk Index, Sunnyvale has higher expected damage per building than 58% of U.S. towns: C+ for hazard risk, #385 of 642 in Texas. Most of the expected damage is river and rain flooding (60%) and hail (23%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Sunnyvale flood?
Flood insurance has paid 6 claims in Sunnyvale since 1991, $97K in all, or 2.1 per 1,000 homes, fewer than 60% of U.S. towns with a flood insurance record.
Is Sunnyvale 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 Dallas County, 40% of homes in mapped flood zones carry federal flood insurance, and 0.8% of all homes do.
How much is flood insurance in Sunnyvale?
FEMA’s Community Rating System list shows no discount for Sunnyvale’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 Sunnyvale?
By FEMA money that reached Sunnyvale, Severe Storms, Straight-line Winds, Tornadoes, and Flooding (2024): 62 households applied for aid, $46K approved, and $269K to the Town of Sunnyvale for repairs.
Is Sunnyvale at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (60%), and Sunnyvale’s rate for it is higher than 52% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Sunnyvale.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Sunnyvale’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.