Wildfire risk in Alameda County: where it is highest, and why
Wildfire risk is not the same everywhere in Alameda County. In the places we scored, overall wildfire risk runs from 12.0 in San Lorenzo up to 76.5 near Livermore, with a county midpoint of 36.6.
Alameda County — the largest fires on record, at their perimeter centres, with the county’s main communities. Select a marker for its detail.
At a glance
Half of Alameda County scores Moderate or worse
We scored 169 points across Alameda County on the same 0–100 scale a Satelife address report uses, and they do not land in one place. 1% of them come out Very High, while 34% are Low. Which end your own parcel sits at is not something a county map can tell you.
37%
27%
34%
Very High1% · 2 of 169 pointsHigh37% · 63 of 169 pointsModerate27% · 46 of 169 pointsLow34% · 58 of 169 points
Safest end we measured12near San Lorenzo · Low
Middle of the county36.6Moderate — half of Alameda County is above this
Most exposed end we measured76.5near Livermore · Very High
And the federal models agree it is a fire county
Relatively HighFEMA National Risk Index — wildfire risk rating · index score 97.7 / 100
$11.6M / yrFEMA NRI — expected annual loss from wildfire · rated Relatively High
0.97%USFS Wildfire Risk to Communities — mean annual burn probability · 90th-percentile cell 1.97%
3.17 ftUSFS WRC — mean conditional flame length · 70% of the county carries burnable fuel
FEMA NRI also rates Alameda County: all-hazards risk Very High · social vulnerability Relatively Low · community resilience Very High · annualised wildfire frequency 0.0058.
Sources: FEMA National Risk Index 1.20.0 (Dec 2025), county record · USFS Wildfire Risk to Communities v2.0, mean of the grid cells inside the county. Both describe the county as a whole, never an address in it.
What does your Alameda County address score?
A county range shows the spread. Your parcel sits somewhere inside it — the report says where, and what to do about it.
Free to request · PDF report with a 0–100 score, the drivers behind it, and a mitigation plan
Local context
What the data says about Alameda County
Looking at the four address-report tiers, High is the most common tier in the county, with 63 scored points in that band. FEMA’s National Risk Index rates Alameda County’s wildfire risk as Relatively High, and its expected annual loss from wildfire as Relatively High.
A separate countywide federal model also shows meaningful exposure: mean annual burn probability is listed as 0.97%, and 70.1% of the county is in places that can burn.
Fire record
Where the fires actually were
Since 1984, 26,161 acres have burned within recorded perimeters in Alameda County, across 44 fire perimeters. That equals 5% of the county.
The largest fire in this record is the Tesla fire (2005) at 6,440 acres.
The most recent large fire is the Little fire (2026), at 1,078 acres.
The Tunnel fire (1991) is notable for destruction: it is listed with 2,900 structures destroyed.
Midway Fire20065,540 acres in totalcrossed into the county
Del Valle P.G.&E. Fire19834,713 acres
Little Fire20261,078 acres
Carnegie #3 Fire19704,390 acres in totalcrossed into the county
Perimeter sources: NIFC Interagency Fire Perimeter History · WFIGS Interagency Perimeters · largest on record: Tesla 2005.
Perimeters are simplified for display; acreage is the figure the source records.
Communities
Where in the county you are matters most
Among the named communities here, higher typical wildfire risk appears in Fairview (51.1), Livermore (47.9), and Pleasanton (45.5). These are all above the county midpoint for the places scored.
Lower typical wildfire risk appears in Albany (12.8), Alameda (17.3), and Oakland (18.0). Other communities fall between those ends, so local differences inside Alameda County are substantial.
Fairviewvillage
51.1 High
Livermorecity · 86,803 people
47.9 Moderate
Pleasantontown · 81,777 people
45.5 Moderate
Fremontcity · 241,110 people
35.4 Moderate
Castro Valleytown · 61,388 people
33.9 Moderate
Newarktown · 49,149 people
29.2 Moderate
San Leandrotown · 88,815 people
26.8 Moderate
Union Citytown · 74,107 people
25.1 Moderate
Dublintown · 64,826 people
23.1 Low
Emeryvilletown · 12,086 people
22.3 Low
9 more communities in Alameda County
Piedmonttown · 11,135 people
21.8 Low
Haywardcity · 159,203 people
20.1 Low
Berkeleycity · 121,363 people
18.8 Low
Oaklandcity · 433,031 people
18 Low
Ashlandvillage · 21,925 people
18 Low
Cherrylandvillage · 14,728 people
18 Low
Alamedacity · 77,624 people
17.3 Low
San Lorenzovillage · 23,452 people
14.3 Low
Albanytown · 19,696 people
12.8 Low
The score is the median of the sampled points nearest that community — a community-scale
indicator, not a score for any individual property in it. Population comes from the
community's own record where the source carries one.
Terrain & fuels
Terrain, vegetation and fuels
Terrain exposure ranges from 5.0 in Newark to 65.0 near Livermore. Steeper or more complex terrain is associated with higher wildfire risk in the inland areas.
Vegetation and fuels show a similar spread, from 5.0 in Newark to 80.0 near Livermore, with a midpoint of 42.3. In Alameda County, higher terrain and higher fuels often show up in the same inland locations.
40median terrain score (max 65 near Livermore)
42.3median vegetation & fuels score (max 80 near Livermore)
LANDFIRE existing vegetation type across Alameda County — the same fuel data that feeds the
vegetation layer of a Satelife property report.
Fire weather
Fire weather across Alameda County
Fire weather was measured across the county, and it is comparatively tight in range: 59.9 in San Lorenzo to 67.9 in Albany, with a midpoint of 60.6.
That narrow spread means fire weather is less variable place to place here than terrain, fuels, or fire history. It still contributes to wildfire risk, but it does not separate neighborhoods as strongly as some other factors in this county.
59.9lowest fire-weather score — near San Lorenzo
67.9highest fire-weather score — near Albany
What drives it
Which part of the risk moves, and which doesn't
The county’s highest scored wildfire risk is near Livermore at 76.5, while the lowest is in San Lorenzo at 12.0. That gap is large enough that where a home sits inside the county matters a lot for exposure.
By tier counts, Very High appears at 2 scored points, High at 63, Moderate at 46, and Low at 58. So the pattern is mixed, but weighted toward High and Low rather than concentrated in just one tier.
Each bar is what one part of the score covers across Alameda County, on the same 0–100 scale.
A long bar is a part of the risk that depends on where you are; a short one is the same
almost everywhere.
Terrain
5–65highest near Livermore
Vegetation & fuels
5–80highest near Livermore
Hazard zone
10–90highest near Fremont
Fire history
5–95highest near Fremont
Fire weather
59.9–67.9highest near Albany
Overall score
12–76.5highest near Livermore
The tick on each bar is the middle value. Tier boundaries — Moderate at 25, High at 50,
Very High at 75 — are the faint lines behind them.
Show every number behind these bars
Layer
Min
Median
Max
Lowest place
Highest place
Points
Terrain
5
40
65
Newark
near Livermore
169
Vegetation & fuels
5
42.3
80
Newark
near Livermore
169
Hazard zone
10
40
90
Newark
near Fremont
169
Fire history
5
5
95
Newark
Fremont
168
Fire weather
59.9
60.6
67.9
San Lorenzo
Albany
169
Composite
12
36.6
76.5
San Lorenzo
near Livermore
169
Independently of Satelife's layers, the USFS Wildfire Risk to Communities grid puts the county's mean annual burn probability at 0.97% (90th percentile cell: 1.97%), with a mean conditional flame length of 3.17 ft. 70% of the 21,248 grid cells inside the county carry burnable fuel at all.
Source: USFS Wildfire Risk to Communities v2.0 (ImageServer, county extent).
CAL FIRE has no mapped Fire Hazard Severity Zone at 5 of the 169 sampled points — the zones cover Local Responsibility Areas. At 3 of them the USFS grid above supplied the hazard reading instead; at the remaining 2 the hazard weight is renormalised away rather than scored as low.
169 sample points on a ~2.3 km grid, plus one at the centre of each community, weighted with the Satelife county profile v1 · median layer coverage 100%. Scores are 0–100 and comparable within the county, not across states.
For a property
What a county range means for one address
Property-by-property features were not measured in this county summary.
What is available for buyers, owners, and agents is area-level wildfire risk context: local scored patterns by community and countywide burn-probability context from the federal model. That model reports mean annual burn probability at 0.97%, with a 90th-percentile cell value of 1.97%, and it shows 70.1% of the county in places that can burn.
Across 169 sampled points in Alameda County, the score runs from
12 to 76.5 — two neighbouring parcels can sit in different tiers.
A county number is the middle of that spread; it says nothing about which end yours is at.
Find out where your Alameda County parcel sits
Slope, the fuel touching the structure, the road out, the fire history within a mile — measured at your address, not averaged across the county.
Free to request · PDF report with a 0–100 score, the drivers behind it, and a mitigation plan
Coverage
ZIP codes we cover in Alameda County
Every one of the 65 ZIP areas that touch Alameda County — we run address-level
reports in all of them. They are grouped by the median score of the points we sampled inside
each, which is a neighbourhood-scale indicator and not a score for any
property: two homes in the same ZIP routinely land in different tiers.
Frequently asked questions about Alameda County wildfire risk
What is the biggest fire listed for Alameda County?
The largest fire in this record is Tesla (2005), at 6,440 acres.
What is the most recent large fire listed?
The most recent large fire is the Little fire (2026), listed at 1,078 acres.
How much of Alameda County has burned since 1984?
The record here shows 26,161 acres burned since 1984, which is 5% of the county.
What does FEMA say about countywide wildfire risk?
FEMA’s National Risk Index rates Alameda County’s wildfire risk as Relatively High and its wildfire expected annual loss rating as Relatively High.
This page is generated from a Alameda County data pack assembled on 2026-08-18 (pack v1.0). Scores are sampled across the
county, not measured at any individual address, and are informational decision support — not a
substitute for official evacuation orders, a fire-agency hazard determination, or an insurer's
underwriting judgement.
Data versions: fema_nri 1.20.0 (Dec 2025) · landfire per adapter · nifc_history All Years View · wfigs current · wrc v2.0 (2024) · zcta Census 2020.
What does your parcel look like, layer by layer?
A county range shows the spread. An address-level Satelife report shows where in that spread your property actually sits — PDF, per-layer score, and a prioritized mitigation plan.
