Wildfire risk in Sierra County is generally elevated in the places we scored. The middle overall score is 61.2, with scores ranging from 30.0 in Sierraville up to 80.7 near Loyalton.
We scored 154 points across Sierra County on the same 0–100 scale a Satelife address report uses, and they do not land in one place. 5% of them come out Very High, while 8% are Moderate. Which end your own parcel sits at is not something a county map can tell you.
FEMA NRI also rates Sierra County: all-hazards risk Very Low · social vulnerability Relatively High · community resilience Relatively Low · annualised wildfire frequency 0.0154.
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 Sierra 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
Most scored locations fall in the High tier: 134 points were High, compared with 13 Moderate and 7 Very High. There were no scored points in the Low tier.
For county-wide context, FEMA’s National Risk Index rates Sierra County’s wildfire risk as “Relatively Moderate,” and its all-hazards risk as “Very Low.”
Since 1984, 135,782 acres have burned in Sierra County fire perimeters, and 22.2% of the county has burned in that period. The county record here includes 59 fire perimeters since 1984.
The largest fire listed is Cottonwood (1994), at 48,111 acres.
The most recent large fire is Bear (2024), at 3,323 acres.
Fire perimeters coloured by decade. Select a perimeter for its name, year and size.
Perimeter sources: NIFC Interagency Fire Perimeter History · WFIGS Interagency Perimeters · largest on record: Cottonwood 1994. Perimeters are simplified for display; acreage is the figure the source records.
Among named communities, Loyalton has the highest median wildfire risk score at 64.4. Downieville (61.1) and Sierra City (60.8) are close to each other and close to the county middle.
Sierraville is lower at 57.0, but it is still in the same countywide risk context where most scored points fall in the High tier. Loyalton is the only listed community here with a reported population, at 740.
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 scores are fairly tight across the county, running from 55.0 near Sierraville to 65.0 near Downieville. That narrower range means terrain contributes to risk differences, but less dramatically than some other factors.
Vegetation and fuels vary more, from 40.0 in Sierraville to 80.0 near Loyalton. This wider spread is associated with bigger place-to-place differences in wildfire risk.
Hazard zone scores are high in many scored places, with a middle value of 88.2 and a high of 93.8 near Downieville. Fire history scores range from 5.0 near Downieville to 95.0 near Loyalton, which also contributes to local contrast.
Fire weather was measured across the scored places in Sierra County. Scores run from 55.5 to 64.5, with a middle value of 62.3.
That spread is modest compared with fuels and fire history, so local weather differences are present but less pronounced in this county’s score pattern.
Wildfire risk is not uniform across Sierra County. The highest overall score, 80.7, is near Loyalton, while the lowest, 30.0, is in Sierraville.
Community-level medians also show that spread: Loyalton is at 64.4, while Sierraville is at 57.0. Downieville (61.1) and Sierra City (60.8) sit close to the county middle.
Each bar is what one part of the score covers across Sierra 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.
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.
| Layer | Min | Median | Max | Lowest place | Highest place | Points |
|---|---|---|---|---|---|---|
| Terrain | 55 | 55 | 65 | near Sierraville | near Downieville | 154 |
| Vegetation & fuels | 40 | 70 | 80 | Sierraville | near Loyalton | 154 |
| Hazard zone | 10 | 88.2 | 93.8 | Sierraville | near Downieville | 154 |
| Fire history | 5 | 20 | 95 | near Downieville | near Loyalton | 154 |
| Fire weather | 55.5 | 62.3 | 64.5 | near Downieville | near Downieville | 154 |
| Composite | 30 | 61.2 | 80.7 | Sierraville | near Loyalton | 154 |
Independently of Satelife's layers, the USFS Wildfire Risk to Communities grid puts the county's mean annual burn probability at 1.48% (90th percentile cell: 2.99%), with a mean conditional flame length of 11.23 ft. 98% of the 25,697 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 95 of the 154 sampled points — the zones cover Local Responsibility Areas, and most of this county is state or federal land. At 95 of them the USFS grid above supplied the hazard reading instead.
154 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-level reality check, the U.S. Forest Service Wildfire Risk to Communities model reports a mean annual burn probability of 1.48%, with a 90th-percentile cell at 2.99%. It also indicates that 98.3% of the county area can burn.
The same model reports mean conditional flame length of 11.23 feet. For an individual home, that measure and the local county score are best read together as exposure indicators, not as a guarantee about any single parcel.
FEMA’s National Risk Index also rates Sierra County’s expected annual wildfire loss as “Relatively Moderate,” while rating social vulnerability as “Relatively High” and community resilience as “Relatively Low.”
Find out where your Sierra 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
Every one of the 20 ZIP areas that touch Sierra 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.
Very High 1 ZIP
High 10 ZIPs
No sampled point inside 9 ZIPs
89511 · 95959 Downieville · 95981 Downieville · 96103 Sierra City · 96106 Sierra City · 96109 Loyalton · 96129 Loyalton · 96135 Loyalton · 96161 Sierraville
Grouped from 11 of 20 ZIP areas — the rest had no sample point fall inside them. The community shown is the nearest mapped place to the ZIP's centre.
ZIP areas are Census 2020 ZIP Code Tabulation Areas intersecting the county boundary.
No. In the places scored, overall wildfire risk ranges from 30.0 in Sierraville to 80.7 near Loyalton, so location within the county matters.
22.2% of the county has burned since 1984, with 135,782 acres inside fire perimeters over that period.
The largest listed fire is Cottonwood (1994), at 48,111 acres. The most recent large fire is Bear (2024), at 3,323 acres.
FEMA’s National Risk Index rates the county’s wildfire risk as “Relatively Moderate,” and its wildfire expected annual loss rating is also “Relatively Moderate.”
The U.S. Forest Service model shows a mean annual burn probability of 1.48% and a 90th-percentile cell at 2.99%, with 98.3% of county area able to burn.
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.
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