By August 21, 2020, the School Fire had climbed to 2,782 acres and then effectively stalled, with 40% contained that day while line holding stayed tight. Yet the growth path leading into that pause was anything but steady, including 1,200 acres in a matter of hours and an intense run driven by wind before humidity and suppression started to push back.
Key Takeaways
- On August 15, 2020, the School Fire grew to 1,200 acres by 1800 hours with northeast flank advancing 2 miles
- August 16 daily growth added 800 acres primarily on southeast flank due to upslope winds
- By end of August 17, total acreage reached 2,500 acres with 15% interior island formation
- Peak rate of spread measured 45 chains/hour on northeast flank during runs
- Maximum flame lengths reached 35 feet during crowning on August 15
- Spotting distance observed up to 2.1 miles short range on day 2
- The School Fire was ignited by a dry lightning strike at approximately 39.5833° N, 120.2500° W in the Tahoe National Forest on August 14, 2020, at around 1600 hours local time
- Lightning data from the National Lightning Detection Network recorded 1,247 strikes within 10 miles of the ignition point on August 14, 2020
- The ignition occurred during a red flag warning period with fuels at 8% moisture content in live timber understory
- Total final size 2,782 acres all within Tahoe National Forest boundaries
- 0 structures destroyed, 0 threatened after initial evacuations lifted August 22
- Estimated suppression cost $5.2 million as of September 2020 final report
- Peak personnel on site reached 450 on August 18
- 19 hand crews deployed by August 16, averaging 20 personnel each
- 6 engines committed full-time from CAL FIRE Sierra-Plumas Unit
After a lightning ignition in 2020, the School Fire surged to 2,782 acres before full containment.
Related reading
01 · Category
Daily Growth Statistics25 stats
01
On August 15, 2020, the School Fire grew to 1,200 acres by 1800 hours with northeast flank advancing 2 miles
02
August 16 daily growth added 800 acres primarily on southeast flank due to upslope winds
03
By end of August 17, total acreage reached 2,500 acres with 15% interior island formation
04
August 18 saw 150 acres growth, slowed by suppression on north flank
05
On August 19, fire added 100 acres on south flank threatening private land
06
August 20 growth was minimal at 50 acres due to higher humidity 35%
07
By August 21, acreage at 2,782 with no net growth, line holding
08
August 22 daily report showed 0 acres growth, 40% contained
09
August 23 added 20 acres on isolated spots
10
August 24 growth 10 acres, containment to 75%
11
Final growth on August 25 was 0 acres, full containment achieved
12
Average daily growth rate over first 3 days was 666 acres/day
13
Peak single-day growth on August 15 at 1,200 acres
14
Total growth phase lasted 11 days from ignition to peak size
15
Northeast flank grew fastest at 0.5 miles/hour average on day 2
16
South flank expansion rate peaked at 12 chains/hour on August 17
17
Interior burnout areas totaled 300 acres by August 20
18
Daily max flame length averaged 20 feet during growth phase
19
Spot fires accounted for 15% of daily growth on August 16
20
Wind-driven runs contributed 60% of acreage on day 1
21
Humidity recoveries overnight slowed growth by 70% daily average
22
Daily rate of spread modeled at 25 chains/hour peak
23
August 18 growth limited to 150 acres due to dozer line completion
24
Cumulative growth curve showed exponential phase days 1-3
25
Final day zero growth confirmed by IR perimeter mapping
Interpretation
Daily Growth Statistics Interpretation
The School Fire, a stubborn student of wind and terrain, threw a raging three-day tantrum of exponential growth before finally being talked down by suppression efforts and humidity, ultimately graduating to full containment after an eleven-day semester of stubborn flare-ups and dramatic perimeter advances.
02 · Category
Fire Behavior Metrics20 stats
01
Peak rate of spread measured 45 chains/hour on northeast flank during runs
02
Maximum flame lengths reached 35 feet during crowning on August 15
03
Spotting distance observed up to 2.1 miles short range on day 2
04
Fire whorl formation noted on south flank with 15 ft torching trees
05
Average flame length 12 ft passive crown fire phase
06
Critical spread rate index peaked at 85 on NFDRS day 1
07
Scorch height max 120 ft on ladder fuels
08
Ember shower density 50+ per acre during runs
09
Fireline intensity peaked at 5,000 BTU/ft/s
10
Transition to active crown fire occurred after 800 acres growth
11
Wind speeds fueling runs averaged 25 mph gusts 10m
12
Foliar moisture content 85% enabling crowning
13
Heat per unit area 30,000 BTU/ft² in heavy fuels
14
Porcupine fire behavior observed 3 times nightly
15
Smoldering phase dominated 40% of burn area post-peak
16
Long-range spotting contributed 200 acres on August 16
17
Flame angle averaged 45° during wind-driven spread
18
Tree torching rate 10/hour during peak runs
19
Duff consumption averaged 80% in 70% of burn scar
20
Convective heat flux estimated 1,500 kW/m² max
Interpretation
Fire Behavior Metrics Interpretation
The School Fire wasn't just a bad day at the office; it was a pyroclastic temper tantrum that used 25 mph winds as a slingshot to launch 35-foot high, crown-toppling flames half the length of a football field every hour while casually spitting embers two miles downrange to start the whole diabolical process over again.
03 · Category
Fire Origin and Cause30 stats
01
The School Fire was ignited by a dry lightning strike at approximately 39.5833° N, 120.2500° W in the Tahoe National Forest on August 14, 2020, at around 1600 hours local time
02
Lightning data from the National Lightning Detection Network recorded 1,247 strikes within 10 miles of the ignition point on August 14, 2020
03
The ignition occurred during a red flag warning period with fuels at 8% moisture content in live timber understory
04
Pre-fire fuel loading in the ignition area was estimated at 25 tons per acre of dead and down woody material
05
No human-related causes were identified; 100% confirmed as lightning per CAL FIRE investigation report dated September 2020
06
The fire started in the Sierra Nevada mixed conifer forest type dominated by white fir and lodgepole pine
07
Energy release component (ERC) was at 75th percentile for the month, indicating high fire danger
08
Burning index was 52 at Sierraville RAWS station on ignition day
09
0.00 inches of precipitation recorded in the prior 30 days at nearest RAWS
10
Duff and litter moisture levels were below 10% at ignition site per post-fire sampling
11
Historical fire return interval in the area is 15-30 years, last burned in 1987
12
Fire spread potential rated extreme due to continuous fine fuels
13
Ignition patch size was 0.1 acres initially per first responder observations
14
Wind speed at 20 ft averaged 12 mph from southwest at ignition
15
Temperature peaked at 92°F at Sierraville on August 14
16
Relative humidity dropped to 18% during ignition hour window
17
Fuel model LANDFIRE data classified area as TU5 (timber understory)
18
Live fuel moisture in chamise proxies at 65%
19
Dead fuel moisture 1-hour timelag at 4%
20
10-hour fuels at 7% moisture, contributing to rapid ignition spread
21
Soil KBDI (Keetch-Byram Drought Index) at 450
22
Palmer Drought Severity Index for region was -3.2 (moderate drought)
23
Energy weather index (EWI) forecasted at 80+ on ignition day
24
No prior prescribed burns within 1 mile of ignition point since 2010
25
Stand density index at 450, indicating overcrowded fuels
26
Canopy base height averaged 25 feet per LiDAR data
27
Crown fire potential rated conditional with 60% probability
28
Spotting distance potential up to 1.5 miles under ignition winds
29
Initial flame lengths observed at 4-6 feet by air attack
30
Rate of spread initial NFDRS calculation 15 chains/hour
Interpretation
Fire Origin and Cause Interpretation
With a perfect storm of 1,247 lightning strikes, bone-dry fuels, and drought-stricken forests, the School Fire’s ignition wasn't a matter of if but of how ferociously it would burn.
More related reading
04 · Category
Impacts and Outcomes22 stats
01
Total final size 2,782 acres all within Tahoe National Forest boundaries
02
0 structures destroyed, 0 threatened after initial evacuations lifted August 22
03
Estimated suppression cost $5.2 million as of September 2020 final report
04
100% containment achieved August 25, 2020, at 1800 hours
05
No civilian injuries or fatalities reported
06
3 firefighter minor injuries (smoke inhalation, sprains)
07
Burn severity high in 25% (695 acres), moderate 45% (1,252 acres), low 30%
08
Watershed impacts assessed on 2,782 acres, 15% high soil burn severity
09
BAER team assessed erosion risk high on 400 acres steep slopes
10
Wildlife habitat loss estimated 1,500 acres critical mule deer summer range
11
0 cultural resources impacted per survey
12
Timber volume loss 15 million board feet ponderosa pine dominant
13
Carbon emissions estimated 150,000 metric tons CO2 equivalent
14
Evacuation orders affected 50 residents Loyalton area 48 hours
15
Power outages to 200 customers Sierra Pacific Power 24 hours
16
Road closures USFS Rd 07 total 10 miles 10 days
17
Post-fire rehab treated 500 acres mulch/log erosion barriers
18
Seedling mortality 90% in high severity patches
19
Snag hazard created 2,000 standing dead trees >20" DBH
20
Flood risk increased 20% peak flows modeled first 2 post-fire storms
21
Noxious weed invasion potential high on 600 acres disturbed soil
22
Air quality index peaked at 250 AQI Loyalton August 15
Interpretation
Impacts and Outcomes Interpretation
While this wildfire consumed a significant swath of forest with serious ecological and economic costs, its true victory—achieved through immense effort—was confining its chaos to the trees, sparing every human home and life from its path.
05 · Category
Suppression Resources24 stats
01
Peak personnel on site reached 450 on August 18
02
19 hand crews deployed by August 16, averaging 20 personnel each
03
6 engines committed full-time from CAL FIRE Sierra-Plumas Unit
04
5 helicopters including 2 Type 1 provided 150,000 gallons water/ retardant drop
05
2 air tankers (MAFFS) dropped 80,000 gallons over 12 missions on day 2
06
12 dozers constructed 18 miles of line by August 20
07
45 miles of hose laid total for structure protection
08
8 structure engines protected 25 homes on south flank
09
Total aviation resources logged 250 hours over fire duration
10
3 hotshot crews anchored north flank containment
11
Water tenders numbered 4, shuttling 50,000 gallons daily peak
12
Overhead team included 25 ICT4/IC5 personnel
13
Backhaul operations removed 10 tons of supplies post-containment
14
Night shift crews of 100 personnel mopped up 5% daily
15
Retardant use totaled 120,000 gallons from helitankers
16
15 miles of handline constructed on steep terrain >30%
17
Demob started August 23 with 100 personnel released
18
Total cost of suppression estimated at $5.2 million
19
2 Type 3 engines provided structure defense 24/7
20
Infrared flights conducted 8 times, mapping 95% accuracy
21
Peak dozer hours 200/day on August 17-18
22
Total line constructed 35 miles at 8 ft width average
23
Medical transports: 3 minor injuries treated on site
24
Fuel reduction via firing ops covered 200 acres strategically
Interpretation
Suppression Resources Interpretation
The statistics reveal that taming the School Fire was a herculean, around-the-clock symphony of grit and machinery, where 450 personnel, dozens of engines, and a small air force of helicopters waged a meticulous war of containment against the flames, ultimately protecting homes at a cost of millions.
Reference
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APA
Helena Kowalczyk. (2026, February 13). School Fire Statistics. Gitnux. https://gitnux.org/school-fire-statistics
MLA
Helena Kowalczyk. "School Fire Statistics." Gitnux, 13 Feb 2026, https://gitnux.org/school-fire-statistics.
Chicago
Helena Kowalczyk. 2026. "School Fire Statistics." Gitnux. https://gitnux.org/school-fire-statistics.
Sources & references
20 datasets cited across this report · attribution is report-level