Skip to content
worldfires
US · United States · →

Monument Fire, July 2021 Trinity

Out · last detection 1 Aug 2021, 21:37 UTC

The fire started on 31 July 2021 in Trinity, United States, and satellites saw it burning for 1 day. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 91,448 hectares, spread across a single county.

It is the 12th largest in California since 2016 (of 442 with a page). Number 5 in United States in 2021, of 385.

Burnt area
91,448ha
official perimeter (MTBS / NIFC)
Duration
1day
31 Jul 2021 – 31 Jul 2021
Municipalities hit
1
counties
Started on
31 Jul
2021
Heat detections
19,119
in a single hotspot: 598 MW
Danger at start
58
Extreme · FWI index
Energy released
4.2GW
sum of detected power

Where it burned

1 Aug 2021
HOTSPOTS BY DAY 31 Jul31 Jul

How it evolved, day by day

311

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

The weather it burned in

37°high
60km/h · peak gust
7%lowest humidity

It had gone 3 days without rain (1 mm or more) when it started.

This area had burned before

2% of the perimeter overlaps earlier fires recorded since 2016: 1,392 ha in 2017.

What happened to each town

  1. Trinity where it started
    91,687 ha reached on 31 Jul
    11 %

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)
31 Jul 36.6 °C 9 % 60 km/h 0.0 mm Extreme 58
1 Aug after 34.5 °C 15 % 49 km/h 0.1 mm Extreme 52
2 Aug after 35.2 °C 12 % 50 km/h 0.0 mm Extreme 53
3 Aug after 35.7 °C 8 % 49 km/h 0.0 mm Extreme 55
4 Aug after 36.4 °C 7 % 52 km/h 0.0 mm Extreme 57
5 Aug after 27.3 °C 18 % 58 km/h 0.0 mm Extreme 51
6 Aug after 30.5 °C 14 % 52 km/h 0.0 mm Extreme 50
7 Aug after 33.6 °C 15 % 54 km/h 0.0 mm Extreme 51
8 Aug after 31.3 °C 20 % 49 km/h 0.0 mm Very high 48
9 Aug after 35.8 °C 12 % 50 km/h 0.0 mm Extreme 52
10 Aug after 38.3 °C 8 % 52 km/h 0.0 mm Extreme 59
11 Aug after 38.7 °C 9 % 59 km/h 0.0 mm Extreme 62
12 Aug after 37.6 °C 12 % 59 km/h 0.0 mm Extreme 61
13 Aug after 36.8 °C 15 % 54 km/h 0.0 mm Extreme 59
14 Aug after 37.7 °C 14 % 49 km/h 0.0 mm Extreme 56
15 Aug after 37.6 °C 12 % 54 km/h 0.0 mm Extreme 59
16 Aug after 29.7 °C 20 % 60 km/h 0.0 mm Extreme 52
17 Aug after 25.3 °C 27 % 64 km/h 0.0 mm Very high 45

Before and after, from space

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

Before · 24 Jul 2021
After · 7 Aug 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 · 19,119Every 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 Monument fire last?
It burned between 31 July 2021 and 31 July 2021: 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 91,448 hectares (914.5 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered Trinity (91,687 ha, 11 %).
What was the weather like?
During the fire the temperature reached 36.6 °C, humidity dropped to 7 % and gusts hit 60 km/h. The fire danger index (FWI) reached 58, 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.

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.

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.