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Hog Fire, July 2020 Lassen

Out · last detection 19 Jul 2020, 21:23 UTC

The fire started on 18 July 2020 in Lassen, United States, and satellites saw it burning for 1 day. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 3,930 hectares, spread across a single county.

It is the 146th largest in California since 2016 (of 442 with a page). Number 130 in United States in 2020, of 441.

Burnt area
3,930ha
official perimeter (MTBS / NIFC)
Duration
1day
18 Jul 2020 – 18 Jul 2020
Municipalities hit
1
counties
Started on
18 Jul
2020
Heat detections
475
in a single hotspot: 310 MW
Danger at start
52
Extreme · FWI index
Energy released
4.2GW
sum of detected power

Where it burned

HOTSPOTS BY DAY 18 Jul18 Jul

How it evolved, day by day

19

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

The weather it burned in

34°high
48km/h · peak gust
10%lowest humidity

It had gone 15 days without rain (1 mm or more) when it started.

This area had burned before

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

What happened to each town

  1. Lassen where it started
    3,931 ha reached on 19 Jul
    0.3 %

Burnt area inside each county, from crossing the official perimeter with administrative boundaries. The distance is from the town centre 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)
18 Jul 33.4 °C 13 % 44 km/h 0.0 mm Extreme 52
19 Jul after 34.1 °C 10 % 44 km/h 0.0 mm Extreme 55
20 Jul after 33.1 °C 12 % 45 km/h 0.6 mm Very high 48
21 Jul after 32.2 °C 13 % 44 km/h 1.6 mm High 34
22 Jul after 29.4 °C 22 % 48 km/h 2.9 mm Moderate 17
23 Jul after 28.6 °C 14 % 45 km/h 1.9 mm High 25
24 Jul after 29.4 °C 20 % 39 km/h 0.6 mm High 31
25 Jul after 30.5 °C 19 % 34 km/h 0.1 mm High 34
26 Jul after 32.7 °C 16 % 48 km/h 0.3 mm Very high 39
27 Jul after 29.8 °C 17 % 48 km/h 0.3 mm Very high 41
28 Jul after 31.2 °C 20 % 35 km/h 0.4 mm Very high 40
29 Jul after 31.7 °C 11 % 42 km/h 0.0 mm Very high 45
30 Jul after 31.9 °C 11 % 44 km/h 0.0 mm Very high 47
31 Jul after 32.7 °C 8 % 42 km/h 0.0 mm Extreme 50
1 Aug after 32.5 °C 7 % 35 km/h 0.0 mm Very high 49
2 Aug after 31.2 °C 12 % 44 km/h 0.0 mm Extreme 52
3 Aug after 31.1 °C 16 % 38 km/h 0.0 mm Very high 47
4 Aug after 31.4 °C 12 % 38 km/h 0.0 mm Very high 49
5 Aug after 29.9 °C 15 % 46 km/h 0.0 mm Extreme 52

Before and after, from space

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

Before · 11 Jul 2020
After · 25 Jul 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 · 475Every 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 Hog fire last?
It burned between 18 July 2020 and 18 July 2020: 1 day, according to the start date recorded by United States agencies (MTBS / NIFC) and the heat detections seen by satellite.
How much area did it burn?
The official perimeter published by United States agencies (MTBS / NIFC) is 3,930 hectares (39.3 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Lassen (3,931 ha, 0.3 %).
What was the weather like?
During the fire the temperature reached 34.1 °C, humidity dropped to 10 % and gusts hit 48 km/h. The fire danger index (FWI) reached 55, 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

Satellite cross-check

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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We will only use your email to reply about this report. Privacy. This is not an emergency service: if there is a fire now, call 911.

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.