How long did the Sugar Fire last?

The official perimeter only gives the start date (2 July 2021). The end comes from the heat detections inside the perimeter: it burned until 24 July 2021 (23 days from 2 July 2021), the last day with detections before more than 10 days in a row without any, so it is approximate.

How much area did it burn?

The official perimeter published by United States agencies (MTBS / NIFC) is 43,900 hectares (439.0 km²). Other tallies, such as daily incident reports, may give slightly different figures.

Which counties burned?

The fire entered 2 counties: Plumas (28,742 ha, 4.2 %); Lassen (15,011 ha, 1.2 %).

What was the weather like?

During the fire the temperature reached 36.1 °C, humidity dropped to 6 % and gusts hit 56 km/h. The fire danger index (FWI) reached 63, class Extreme.

Where does this data come from?

From the official burnt perimeter of United States agencies (MTBS / NIFC, public domain), NASA FIRMS VIIRS hotspots and the administrative boundaries of United States. It is not an official report.

US · United States · 2021-07-02 → 2021-07-24

Sugar Fire, July 2021 Plumas, Lassen

Out · last detection 24 Jul 2021, 20:46 UTC

The fire started on 2 July 2021 in Plumas, United States, and satellites saw it burning for 23 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 43,900 hectares, spread across 2 counties.

It is the 24th largest in California since 2016 (of 442 with a page). Number 14 in United States in 2021, of 385.

Compare with…

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Burnt area: 43,900ha; official perimeter (MTBS / NIFC)
Duration: ≈ 23days; 2 Jul 2021 – 24 Jul 2021
Counties hit: 2; counties
Started on: 2 Jul; 2021
Heat detections: 4,743; in a single hotspot: 1,418 MW
Danger at start: 44; Very high · FWI index
Average daily power: 12.4GW; detected power per day, on average

HOTSPOTS BY DAY 2 Jul24 Jul

Play back 24 Jul 2021

How it evolved, day by day

3 Jul 8 Jul 9 Jul 10 Jul 12 Jul 14 Jul 16 Jul 24 Jul

Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.

The weather it burned in

36°high

56km/h · peak gust

6%lowest humidity

It had gone 29 days without rain (1 mm or more) when it started. Rain came after the fire: 2.2 mm on 27 Jul.

This area had burned before

No earlier perimeters overlap this fire since 2016, when the satellite record begins.

How big is it?

It burned the equivalent of 28% of the area of London (439 km² against 1,583 km²).

London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).

This compares size, not location: both shapes are at the same scale, north up, centred on each other.

What happened to each county

Plumas where it started

28,742 ha reached on 3 Jul

4.2 %
Lassen

15,011 ha reached on 9 Jul

1.2 %

Burnt area inside each county, from crossing the official perimeter with administrative boundaries. The distance runs from the point marking the centre of each area to the nearest fire: staying a kilometre away does not mean it reached the houses.

The weather day by day

ECMWF ERA5 reanalysis at the fire location, the standard reference for past weather, and the Canadian Fire Weather Index (the same system Copernicus uses), computed by WorldFires from that data. Days after the fire run until the first rain.

Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)

Day	High	Min. humidity	Peak gust	Rain	Danger (FWI)
2 Jul	30.5 °C	17 %	38 km/h	0.4 mm	Very high 44
3 Jul	31.3 °C	18 %	42 km/h	3.0 mm	High 22
4 Jul	29.2 °C	20 %	44 km/h	0.4 mm	High 34
5 Jul	32.3 °C	14 %	37 km/h	0.0 mm	Very high 43
6 Jul	32.8 °C	15 %	45 km/h	0.1 mm	Very high 45
7 Jul	32.3 °C	11 %	44 km/h	0.0 mm	Very high 48
8 Jul	33.0 °C	6 %	54 km/h	0.0 mm	Extreme 58
9 Jul	35.1 °C	12 %	46 km/h	0.0 mm	Extreme 53
10 Jul	36.1 °C	12 %	46 km/h	0.0 mm	Extreme 57
11 Jul	35.2 °C	12 %	55 km/h	0.0 mm	Extreme 58
12 Jul	35.3 °C	6 %	56 km/h	0.0 mm	Extreme 63
13 Jul	32.8 °C	12 %	48 km/h	0.0 mm	Extreme 60
14 Jul	32.3 °C	10 %	54 km/h	0.0 mm	Extreme 58
15 Jul	28.9 °C	11 %	52 km/h	0.0 mm	Extreme 56
16 Jul	29.5 °C	9 %	47 km/h	0.0 mm	Extreme 55
17 Jul	31.1 °C	9 %	51 km/h	0.0 mm	Extreme 56
18 Jul	31.4 °C	14 %	38 km/h	0.0 mm	Extreme 53
19 Jul	30.0 °C	20 %	50 km/h	0.5 mm	Very high 48
20 Jul	29.3 °C	14 %	50 km/h	0.0 mm	Very high 50
21 Jul	29.9 °C	11 %	54 km/h	0.0 mm	Extreme 53
22 Jul	30.5 °C	13 %	54 km/h	0.0 mm	Extreme 52
23 Jul	32.1 °C	11 %	29 km/h	0.0 mm	Very high 48
24 Jul	32.6 °C	12 %	32 km/h	0.0 mm	Very high 48
25 Jul after	33.8 °C	15 %	46 km/h	0.2 mm	Very high 50
26 Jul after	31.2 °C	18 %	31 km/h	0.0 mm	Very high 47
27 Jul after	23.7 °C	32 %	40 km/h	2.2 mm	Moderate 12

Before and after, from space

Drag the line to compare the same ground before the fire and after it.

↔

Before · 25 Jun 2021

After · 31 Jul 2021

Before After

If the day is cloudy, change the date: each satellite passes once a day. In false colour the burnt ground looks brown or red.

Detections table · 4,743Every satellite heat detection, one by one, with time, satellite, power and coordinates.

⬇ Download CSV Times in UTC. Each detection is a 375 m pixel: a large fire yields hundreds per pass.

Date and time	Satellite	FRP (MW)	Lat	Lon

Other fires nearby

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Frequently asked questions

How long did the Sugar Fire last?: The official perimeter only gives the start date (2 July 2021). The end comes from the heat detections inside the perimeter: it burned until 24 July 2021 (23 days from 2 July 2021), the last day with detections before more than 10 days in a row without any, so it is approximate.
How much area did it burn?: The official perimeter published by United States agencies (MTBS / NIFC) is 43,900 hectares (439.0 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?: The fire entered 2 counties: Plumas (28,742 ha, 4.2 %); Lassen (15,011 ha, 1.2 %).
What was the weather like?: During the fire the temperature reached 36.1 °C, humidity dropped to 6 % and gusts hit 56 km/h. The fire danger index (FWI) reached 63, class Extreme.
Where does this data come from?: From the official burnt perimeter of United States agencies (MTBS / NIFC, public domain), NASA FIRMS VIIRS hotspots and the administrative boundaries of United States. It is not an official report.

Where to verify it

A satellite detection is not an official report. Final figures and the fire’s status are published by each country’s emergency service.

Emergency number: 911 · Emergency number and official warnings ›

Satellite cross-check

NASA FIRMS ↗
NIFC · Fire maps ↗

History of this page Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.

No changes since 24 October 2026.

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How we know this

Perimeter: MTBS (US Geological Survey and US Forest Service), official.
The official perimeter has no end date: the end is the last day with VIIRS detections inside the perimeter before a gap of more than 10 days (150 days at most), so it is approximate. 4,743 Suomi-NPP VIIRS detections on those dates.
We have not matched this page with any official record.
Weather: Copernicus ERA5 reanalysis at the fire location, in cells of about 25 km.

How we build fire pages: methodology ›

Where this data comes from

The perimeter is official and in the public domain. For past years it comes from MTBS (Monitoring Trends in Burn Severity), run by the U.S. Geological Survey and the USDA Forest Service, which map it on Landsat and Sentinel-2 imagery. For the current and last year it comes from WFIGS at the National Interagency Fire Center (NIFC): incident perimeters mapped by fire crews, aircraft and imagery. Heat detections come from the VIIRS sensors aboard Suomi-NPP and NOAA-20, distributed by NASA FIRMS at 375 m resolution. County boundaries come from geoBoundaries ADM2 (Public Domain). The area per county is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ slightly from official figures.

Where it burned