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Slater Fire, September 2020 Siskiyou, Josephine, Del Norte

Out · last detection 5 Nov 2020, 10:57 UTC

The fire started on 8 September 2020 in Del Norte, United States, and satellites saw it burning for 59 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 63,802 hectares, spread across 3 counties.

It is the 15th largest in California since 2016 (of 442 with a page). Number 16 in United States in 2020, of 441.

Compare with…

Suggestions: Natchez · 2018Oak · 2017Cedar · 2017Kelly · 2023

Burnt area
63,802ha
official perimeter (MTBS / NIFC)
Duration
≈ 59days
8 Sept 2020 – 5 Nov 2020
Counties hit
3
counties
Started on
8 Sept
2020
Heat detections
7,941
in a single hotspot: 1,006 MW
Danger at start
46
Very high · FWI index
Average daily power
3.1GW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 8 Sept5 Nov
5 Nov 2020

How it evolved, day by day

8 Sept 2020 · 57,794 MW · 784 9 Sept 2020 · 56,216 MW · 2513 10 Sept 2020 · 8,670 MW · 1126 11 Sept 2020 · 3,300 MW · 625 12 Sept 2020 · 1,877 MW · 411 13 Sept 2020 · 2,476 MW · 401 14 Sept 2020 · 4,095 MW · 433 15 Sept 2020 · 2,846 MW · 536 16 Sept 2020 · 1,540 MW · 393 17 Sept 2020 · 138 MW · 29 18 Sept 2020 · 86 MW · 54 19 Sept 2020 · 134 MW · 21 20 Sept 2020 · 775 MW · 141 21 Sept 2020 · 156 MW · 116 22 Sept 2020 · 68 MW · 45 23 Sept 2020 · 139 MW · 35 26 Sept 2020 · 4 MW · 3 27 Sept 2020 · 12 MW · 5 28 Sept 2020 · 25 MW · 4 29 Sept 2020 · 8 MW · 6 30 Sept 2020 · 15 MW · 6 1 Oct 2020 · 30 MW · 19 2 Oct 2020 · 113 MW · 29 3 Oct 2020 · 19 MW · 14 4 Oct 2020 · 37 MW · 13 5 Oct 2020 · 31 MW · 18 6 Oct 2020 · 86 MW · 29 7 Oct 2020 · 163 MW · 36 8 Oct 2020 · 47 MW · 17 9 Oct 2020 · 12 MW · 8 16 Oct 2020 · 0 MW · 1 17 Oct 2020 · 2 MW · 1 20 Oct 2020 · 1 MW · 1 23 Oct 2020 · 6 MW · 4 26 Oct 2020 · 1 MW · 1 27 Oct 2020 · 15 MW · 8 28 Oct 2020 · 26 MW · 13 29 Oct 2020 · 18 MW · 9 30 Oct 2020 · 59 MW · 4 31 Oct 2020 · 3 MW · 1 1 Nov 2020 · 7 MW · 4 2 Nov 2020 · 23 MW · 12 3 Nov 2020 · 17 MW · 8 4 Nov 2020 · 2 MW · 2 5 Nov 2020 · 1 MW · 2
8 Sept 15 Sept 22 Sept 1 Oct 8 Oct 27 Oct 3 Nov

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

The weather it burned in

30°high
68km/h · peak gust
12%lowest humidity

It had gone 13 days without rain (1 mm or more) when it started. Rain came after the fire: 11.9 mm on 6 Nov.

This area had burned before

4% of the perimeter overlaps earlier fires recorded since 2016: 704 ha in 2017, 1,822 ha in 2018.

How big is it?

10 km
It burned the equivalent of 40% of the area of London (638 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

  1. Siskiyou
    32,900 ha reached on 8 Sept
    2.0 %
  2. Josephine
    18,467 ha reached on 8 Sept
    4.3 %
  3. Del Norte where it started
    12,637 ha reached on 9 Sept
    4.8 %

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.

People and buildings inside the perimeter

GHSL 2020
Built-up area18 ha
Residents≈ 600

Inside the perimeter there were about 18 hectares of built-up land and about 600 residents (GHSL 2020, satellite-based estimate).

This is an estimate on 100 m cells, made from satellite imagery and census data: it does not mean that homes burned or that anyone was harmed. The perimeter also contains land that never burned.

Source: Global Human Settlement Layer (GHS-BUILT-S and GHS-POP R2023A), European Commission Joint Research Centre (JRC), © European Union, CC BY 4.0. Sum inside the perimeter computed by WorldFires. human-settlement.emergency.copernicus.eu

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)
8 Sept 25.6 °C 12 % 44 km/h 0.0 mm Very high 46
9 Sept 30.0 °C 12 % 24 km/h 0.0 mm Very high 40
10 Sept 27.1 °C 18 % 30 km/h 0.0 mm Very high 38
11 Sept 26.1 °C 28 % 30 km/h 0.0 mm High 32
12 Sept 24.8 °C 32 % 29 km/h 0.0 mm High 30
13 Sept 24.1 °C 30 % 44 km/h 0.0 mm High 33
14 Sept 22.1 °C 26 % 48 km/h 0.0 mm High 35
15 Sept 24.3 °C 24 % 35 km/h 0.0 mm High 31
16 Sept 22.1 °C 41 % 38 km/h 0.0 mm High 27
17 Sept 19.3 °C 53 % 44 km/h 3.3 mm Low 5
18 Sept 15.0 °C 79 % 49 km/h 4.0 mm Very low 0
19 Sept 20.2 °C 39 % 33 km/h 0.0 mm Very low 5
20 Sept 22.5 °C 27 % 24 km/h 0.0 mm Moderate 12
21 Sept 20.7 °C 42 % 35 km/h 0.0 mm Moderate 15
22 Sept 19.4 °C 39 % 38 km/h 0.0 mm Moderate 18
23 Sept 19.6 °C 42 % 68 km/h 0.4 mm High 22
24 Sept 17.3 °C 44 % 52 km/h 5.3 mm Very low 2
25 Sept 14.0 °C 49 % 44 km/h 2.5 mm Very low 2
26 Sept 17.9 °C 54 % 32 km/h 0.6 mm Very low 4
27 Sept 22.4 °C 31 % 56 km/h 0.0 mm Moderate 15
28 Sept 30.0 °C 16 % 46 km/h 0.0 mm High 27
29 Sept 28.0 °C 18 % 23 km/h 0.0 mm High 24
30 Sept 26.2 °C 22 % 30 km/h 0.0 mm High 27
1 Oct 27.1 °C 24 % 34 km/h 0.0 mm High 28
2 Oct 25.9 °C 25 % 35 km/h 0.0 mm High 28
3 Oct 25.5 °C 25 % 25 km/h 0.0 mm High 27
4 Oct 21.7 °C 28 % 31 km/h 0.0 mm High 25
5 Oct 25.3 °C 24 % 23 km/h 0.0 mm High 25
6 Oct 25.3 °C 21 % 24 km/h 0.0 mm High 25
7 Oct 22.2 °C 23 % 34 km/h 0.0 mm High 27
8 Oct 20.7 °C 24 % 26 km/h 0.0 mm High 26
9 Oct 19.3 °C 37 % 38 km/h 0.0 mm High 24
10 Oct 11.8 °C 76 % 65 km/h 15.3 mm Very low 0
11 Oct 15.6 °C 52 % 42 km/h 0.0 mm Very low 2
12 Oct 18.2 °C 49 % 34 km/h 1.3 mm Very low 3
13 Oct 18.7 °C 60 % 44 km/h 0.0 mm Very low 5
14 Oct 18.2 °C 28 % 42 km/h 0.0 mm Moderate 12
15 Oct 19.4 °C 29 % 50 km/h 0.0 mm Moderate 17
16 Oct 23.1 °C 28 % 41 km/h 0.0 mm Moderate 18
17 Oct 21.8 °C 36 % 37 km/h 0.0 mm Moderate 19
18 Oct 22.2 °C 32 % 31 km/h 0.0 mm Moderate 18
19 Oct 20.2 °C 30 % 35 km/h 0.0 mm Moderate 19
20 Oct 20.0 °C 44 % 40 km/h 0.0 mm Moderate 18
21 Oct 14.7 °C 38 % 50 km/h 0.0 mm Moderate 20
22 Oct 11.7 °C 25 % 52 km/h 0.0 mm Moderate 20
23 Oct 16.7 °C 22 % 40 km/h 0.0 mm Moderate 20
24 Oct 14.0 °C 57 % 35 km/h 0.0 mm Moderate 15
25 Oct 10.6 °C 14 % 53 km/h 0.0 mm High 22
26 Oct 13.8 °C 13 % 42 km/h 0.0 mm High 23
27 Oct 19.1 °C 21 % 32 km/h 0.0 mm High 23
28 Oct 20.4 °C 17 % 26 km/h 0.0 mm High 24
29 Oct 21.4 °C 16 % 20 km/h 0.0 mm High 26
30 Oct 19.9 °C 22 % 29 km/h 0.0 mm High 26
31 Oct 20.3 °C 32 % 19 km/h 0.0 mm High 22
1 Nov 21.7 °C 24 % 21 km/h 0.0 mm High 22
2 Nov 20.8 °C 23 % 29 km/h 0.0 mm High 24
3 Nov 17.5 °C 26 % 40 km/h 0.0 mm High 26
4 Nov 17.3 °C 47 % 41 km/h 0.0 mm Moderate 20
5 Nov 17.6 °C 50 % 56 km/h 2.2 mm Low 7
6 Nov after 7.1 °C 52 % 51 km/h 11.9 mm Very low 0

Before and after, from space

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

Before · 1 Sept 2020
After · 12 Nov 2020

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 · 7,941Every 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 timeSatelliteFRP (MW)LatLon

Other fires nearby

All fires in United States ›

Frequently asked questions

How long did the Slater Fire last?
The official perimeter only gives the start date (8 September 2020). The end comes from the heat detections inside the perimeter: it burned until 5 November 2020 (59 days from 8 September 2020), 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 63,802 hectares (638.0 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire entered 3 counties: Siskiyou (32,900 ha, 2.0 %); Josephine (18,467 ha, 4.3 %); Del Norte (12,637 ha, 4.8 %).
What was the weather like?
During the fire the temperature reached 30.0 °C, humidity dropped to 12 % and gusts hit 68 km/h. The fire danger index (FWI) reached 46, class Very high.
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

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.

RSS Changes to this page

Does something look wrong on this page?

This page is built from satellite data and official records, and it sometimes gets things wrong: the wrong dates, the wrong town, two fires merged into one, or something that was not a wildfire at all. If you know this fire first-hand (you live nearby, saw it, fought it or reported on it), tell us what really happened and we will check it.

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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. 7,941 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.
  • Built-up area and population come from the JRC Global Human Settlement Layer (epoch 2020, 100 m cells), summed inside the perimeter: an estimate of what was there, not a damage count.

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.