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Palisades Fire, May 2021 Los Angeles

Out · last detection 23 May 2021, 08:47 UTC

The fire started on 15 May 2021 in Los Angeles, United States, and satellites saw it burning for 9 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 554 hectares, spread across a single county.

It is the 381th largest in California since 2016 (of 442 with a page). Number 330 in United States in 2021, of 385.

The power measured by the satellite is low (25.8 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.

Compare with…

Suggestions: Sherpa · 2016Gifford · 2025Palisades · 2025Saddleridge · 2019

Burnt area
554ha
official perimeter (MTBS / NIFC)
Duration
≈ 9days
15 May 2021 – 23 May 2021
Counties hit
1
counties
Started on
15 May
2021
Heat detections
37
in a single hotspot: 26 MW
Danger at start
16
Moderate · FWI index
Average daily power
106MW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 15 May23 May
23 May 2021

How it evolved, day by day

16 May 2021 · 160 MW · 28 17 May 2021 · 157 MW · 8 23 May 2021 · 1 MW · 1
16 May 17 May 23 May

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

The weather it burned in

20°high
46km/h · peak gust
34%lowest humidity

It had gone 55 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.

How big is it?

10 km
It burned the equivalent of 0.3% of the area of London (5.5 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. Los Angeles where it started
    548 ha reached on 16 May
    0.0 %

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 area0.23 ha
Residents< 20

Inside the perimeter there were about 0.23 hectares of built-up land and almost nobody lived there (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)
15 May 17.4 °C 56 % 38 km/h 0.0 mm Moderate 16
16 May 15.5 °C 63 % 31 km/h 0.0 mm Moderate 14
17 May 18.0 °C 60 % 40 km/h 0.0 mm Moderate 15
18 May 20.4 °C 53 % 29 km/h 0.0 mm Moderate 15
19 May 19.6 °C 56 % 34 km/h 0.0 mm Moderate 16
20 May 18.6 °C 52 % 37 km/h 0.0 mm Moderate 17
21 May 18.5 °C 34 % 46 km/h 0.0 mm High 27
22 May 16.6 °C 48 % 43 km/h 0.0 mm High 23
23 May 19.0 °C 47 % 40 km/h 0.0 mm High 23
24 May after 25.1 °C 30 % 45 km/h 0.0 mm High 31
25 May after 23.8 °C 39 % 33 km/h 0.0 mm High 27
26 May after 20.5 °C 55 % 36 km/h 0.0 mm High 22
27 May after 19.2 °C 54 % 33 km/h 0.0 mm Moderate 20
28 May after 19.9 °C 55 % 35 km/h 0.0 mm Moderate 19
29 May after 18.2 °C 58 % 35 km/h 0.0 mm Moderate 19
30 May after 19.0 °C 58 % 31 km/h 0.0 mm Moderate 18
31 May after 20.2 °C 57 % 30 km/h 0.0 mm Moderate 17
1 Jun after 21.5 °C 56 % 33 km/h 0.0 mm Moderate 19
2 Jun after 21.8 °C 56 % 31 km/h 0.0 mm Moderate 18

Its twins: fires that started in the same weather

It started with an FWI of 16.4, a minimum humidity of 56% and 55 days without rain. Fires in the area that started in weather like this since 2016: 2.

FWI at the start 16.4
Minimum humidity 56 %
Days without rain 55
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Sherpa Fire, June 2016
3,058 ha 7 days FWI 20.7 Min. humidity 55 % 142 km away, in 2016

First rain (1 mm or more) after it ended: none in the following ten days.

See its page Compare with this fire

What happened to them

Fires in the area that started in similar weather: 2. With fewer than 15 we give no figures: they would be more noise than signal.

This is a bank of analogues: it shows what usually happens, not what will happen. With fewer than 15 twins we give no figures. How we calculate it

How it ended

—first rain
—no rain in ten days
46km/h · max. gust

It was considered over on 23 May, and not even 1 mm fell in the following ten days: it went out without rain.

Weather on this page: Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)

How a twin is chosen

  • Same area: fires that have already ended, less than 250 km from this one, since 2016.
  • Same start: we compare the FWI on the first day, the minimum humidity that day and the run of days without rain before it. The slider sets how much they may differ.
  • Only pages with final weather data (ERA5 reanalysis) calculated in the same way as this fire’s; agricultural and grass burns and pages with data under review are left out.
  • Fires burning at the same time as this one (a week before or after) are left out: they share the same spell of weather and do not count as a precedent.
  • They are sorted by similarity, and the outlines of the first five are drawn.

How we calculate it

Before and after, from space

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

Before · 8 May 2021
After · 30 May 2021

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 · 37Every 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 Palisades Fire last?
The official perimeter only gives the start date (15 May 2021). The end comes from the heat detections inside the perimeter: it burned until 23 May 2021 (9 days from 15 May 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 554 hectares (5.5 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Los Angeles (548 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 20.4 °C, humidity dropped to 34 % and gusts hit 46 km/h. The fire danger index (FWI) reached 27, class 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 With cross-checks and a citable version

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.

Report an error
What do you think is wrong?

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.

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. 37 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.