Understanding Your Wildfire Intelligence Metrics

Low (Stable/ Cooling): Temperatures are dropping, and humidity is rising. Rain is likely within the window.

Moderate (Persistent Dryness): No rain in sight, but winds are light. Fuels continue to dry at a steady pace.

High (Deteriorating): Forecast shows a "Heating Trend" with dropping humidity and increasing afternoon winds.

Extreme (Critical Event): Forecast predicts a "Red Flag" event (High Winds + Low RH) or a lightning outbreak.

Low (0-50): Air quality is satisfactory. No special precautions are needed for outdoor activities.

Moderate (51-100): Acceptable air, but unusually sensitive people (like those with severe asthma) should consider reducing heavy exertion.

High (101-200): Sensitive groups (children, seniors, pregnant people) should stay inside. At 151+, everyone should limit time outdoors.

Extreme (>201): Health alert for everyone. Avoid all outdoor activity. N95 masks are recommended if you must go out.

Low (0-500 feet): Within the standard length of a "pre-connected" hose line. Most homes in this range receive the best insurance ratings.

Moderate (501-1,000 feet): Firefighters must "lay more hose" to reach the building, which can take extra time. This is the maximum distance for standard municipal protection.

High (1,001-2,500 feet): Beyond standard hose capabilities. Insurance premiums often rise significantly here as the community may be downgraded to a lower protection class.

Extreme (>2,500 feet): Responders must bring "water tenders" (tanker trucks) and set up portable pools. High risk for total property loss in a wildfire.

Low (0-5 MPH): Embers mostly fall within the fire's own perimeter. Fire-resistant vents are highly effective.

Moderate (6-15 MPH): Embers can travel up to 1 mile. Spot fires start to appear outside the main fire line.

High (16-25 MPH): Critical Red Flag threshold. Embers penetrate standard vents and ignite debris in gutters and under decks.

Extreme (>25 MPH): Embers travel several miles. Wind-driven rain-compliant vents are required to resist high-pressure ember entry

Low: The environment is currently too wet or cold for fires to easily start or spread.

Moderate: Conditions are drying out. Accidental fires are possible and could begin to "carry" through dry grass.

High: The landscape is primed for fire. Any spark could quickly turn into a fast-moving wildfire that is difficult to control.

Extreme: The "Perfect Storm" for fire. Expect erratic fire behavior, intense heat, and embers that can start new fires miles away.

Low (2 - 3): The atmosphere is stable and moist. Large fire growth is unlikely.

Moderate (4): Atmospheric conditions are normal. Fire growth potential is low to moderate.

High (5): Conditions are becoming unstable and dry. There is a moderate potential for large fire growth.

Extreme (6): The atmosphere is highly unstable and very dry. There is a high potential for extreme fire behavior, such as crowning, spotting, and massive plume domination.

Low: No major fires in recorded history or very rare occurrences. Your area has natural "fire breaks" or a climate that doesn't support big fires.

Moderate: Small, infrequent fires have happened nearby. The landscape can burn, but it hasn't shown a pattern of high-intensity "mega-fires".

High: Multiple large fire perimeters overlap or are adjacent to your location. You live in a "Fire Corridor." The local geography (like a canyon) naturally funnels fire toward you.

Extreme: Frequent, intense fires occur every few decades. This is a "High-Frequency" zone. The vegetation is designed to burn and regrow quickly.

Low (0-10%): Fuels do not ignite readily. While intense heat (like lightning) might start a fire, small sparks or embers are unlikely to cause a fire that spreads.

Moderate (11-20%): Fires can start from most accidental causes. Although fires spread freely in dry grass, they move slowly in timber and are generally easy to control.

High (21-45%): Fine dead fuels ignite easily from most causes. Fires spread rapidly, and "spotting" (embers starting new fires nearby) is common.

Extreme (>45%): Fires start quickly, spread furiously, and burn intensely. Every start is potentially serious and can become unmanageable almost instantly.

Low (0-200): Fuels are wet. Fires are rare, stay small, and are easy to extinguish.

Moderate (201-400): Surface leaves are drying. Fires spread more easily and will burn through the night.

High (401-600): Fire intensity increases. Logs and heavy wood begin to burn actively and may smolder for days.

Extreme: (601-800): Fire burns underground into roots and stumps. Expect erratic behavior and fire "spotting" (embers starting new fires far away).

Reported in miles from target address.

Low (0-5): Direct attack with hand tools is still effective; fires are generally easy to suppress.

Moderate (6-20): Hand tools become less effective; engines and water drops are often required to support ground crews.

High (21-50): Direct attack at the head is difficult or impossible; heavy equipment like dozers and aircraft are required.

Extreme (50-100): Extreme intensity; direct attack is dangerous. Indirect attack (creating lines far ahead of the fire) is usually necessary.

Low (>40%): High humidity helps fuels absorb moisture from the air, making them harder to ignite and slowing down any active flames.

Moderate (30-40%): Fine fuels begin to dry out. Fires are plausible and can spread at a moderate pace, but control is generally not difficult.

High (20-30%): Rapid drying of vegetation. Fires start easily, spread quickly, and may produce short-distance "spotting" (embers starting new fires).

Extreme (<20%): Critically low fuel moisture. Expect extreme, erratic behavior; fires will ignite from almost any cause and spread faster than crews can travel.

Low (Flat 0-5% slope): Fire moves at its "base speed." Wind is the only major factor pushing the flames forward.

Moderate (Gentle 6-15% slope): Fire begins to tilt toward the fuel. You will see a noticeable increase in speed compared to flat ground.

High (Steep 16-40% slope): Flames are tilted very close to the fuel. Fires can spread twice as fast as on flat ground.

Extreme (Precipitous >40% slope): Fire can "race" up the slope faster than humans can run. Indirect attack is usually the only safe option.

Low (<1.0 kPa): High fuel moisture; fires are unlikely to start and spread very slowly.

Moderate (1.0-2.0 kPa): Fine fuels (grass/needles) begin to dry rapidly; fires are plausible from accidental causes.

High (2.1-3.5 kPa): Critical drying of 1-hour and 10-hour fuels; fires become difficult to control, especially with wind.

Extreme (>3.5 kPa): Live fuel moisture drops significantly; expect extreme, erratic behavior and high-intensity "crown" fires.

Low (0-70th percentile): Weather is typical for this time of year; fire behavior matches historical expectations.

Moderate (71-85th percentile): Warmer and drier than usual; fuels are drying out faster than the 10-year average.

High (85-95th percentile): Near-record heat or dryness; fire behavior will be aggressive and containment will be difficult.

Extreme (96th-100th percentile): The "hottest/driest ever recorded" for this date; fuels are at critical tipping points; expect "megafire" behavior.

Low (0-30): Fires are unlikely to start; if they do, they spread slowly and are easily controlled.

Moderate (31-60): Fires can start from most accidental causes. Control is usually not difficult if caught early.§

High (61-85): Fires start easily and spread rapidly. Direct attack is difficult; “spotting”, where a fire jumps ahead of itself, is common.

Extreme (86-100): Critical Situation. Explosive growth, long-range spotting, and erratic behavior. Control is often impossible.

Low (0-5 MPH): Fire spread is primarily driven by fuel and slope rather than wind. Smoke rises mostly vertically.

Moderate (6-12 MPH): Flames begin to tilt, pre-heating fuel ahead of the fire. Hand lines can still be effective, but spread increases.

High (13-24 MPH): Fire begins to "pulse" and move rapidly. Embers are carried downwind, starting new fires (spotting). Direct attack at the head is dangerous.

Extreme (>25 MPH): Wind-dominated fire behavior. Rapid, uncontrollable growth and long-range spotting are expected. Fire behavior becomes erratic and life-threatening.