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Rattlesnake Fire, April 2018 Greenlee, Graham, Apache

Out · last detection 9 May 2018, 09:00 UTC

The fire started on 11 April 2018 in Greenlee, United States, and satellites saw it burning for 29 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 11,079 hectares, spread across 3 counties.

It is the 29th largest in Arizona since 2016 (of 380 with a page). Number 66 in United States in 2018, of 511.

Compare with…

Suggestions: Horton · 2021Bear · 2021Foote · 2024Bringham · 2020

Burnt area
11,079ha
official perimeter (MTBS / NIFC)
Duration
≈ 29days
11 Apr 2018 – 9 May 2018
Counties hit
3
counties
Started on
11 Apr
2018
Heat detections
1,335
in a single hotspot: 252 MW
Danger at start
27
High · FWI index
Average daily power
1.0GW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 11 Apr9 May
9 May 2018

How it evolved, day by day

11 Apr 2018 · 15 MW · 2 12 Apr 2018 · 121 MW · 14 13 Apr 2018 · 434 MW · 31 14 Apr 2018 · 318 MW · 37 15 Apr 2018 · 729 MW · 75 16 Apr 2018 · 2,828 MW · 133 17 Apr 2018 · 1,334 MW · 78 18 Apr 2018 · 1,006 MW · 92 19 Apr 2018 · 267 MW · 43 20 Apr 2018 · 719 MW · 76 21 Apr 2018 · 146 MW · 18 22 Apr 2018 · 742 MW · 66 23 Apr 2018 · 868 MW · 66 24 Apr 2018 · 2,759 MW · 188 25 Apr 2018 · 6,149 MW · 187 26 Apr 2018 · 287 MW · 46 27 Apr 2018 · 2,376 MW · 92 28 Apr 2018 · 241 MW · 62 29 Apr 2018 · 109 MW · 26 30 Apr 2018 · 13 MW · 2 9 May 2018 · 0 MW · 1
11 Apr 14 Apr 17 Apr 20 Apr 23 Apr 25 Apr 26 Apr 29 Apr

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

The weather it burned in

27°high
90km/h · peak gust
6%lowest humidity

It had gone 14 days without rain (1 mm or more) when it started.

This area had burned before

0% of the perimeter overlaps earlier fires recorded since 2016: 31 ha in 2017.

How big is it?

10 km
It burned the equivalent of 7% of the area of London (111 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. Greenlee where it started
    9,008 ha reached on 13 Apr
    1.9 %
  2. Graham
    1,412 ha reached on 13 Apr
    0.1 %
  3. Apache
    723 ha reached on 11 Apr
    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 area< 0.1 ha
Residents< 20

Inside the perimeter there was no noticeable 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)
11 Apr 20.3 °C 9 % 55 km/h 0.0 mm High 27
12 Apr 15.8 °C 15 % 90 km/h 0.2 mm High 36
13 Apr 6.0 °C 12 % 76 km/h 0.0 mm High 31
14 Apr 14.6 °C 9 % 35 km/h 0.0 mm Moderate 21
15 Apr 17.5 °C 8 % 45 km/h 0.0 mm High 26
16 Apr 17.0 °C 7 % 64 km/h 0.0 mm High 33
17 Apr 13.0 °C 11 % 72 km/h 0.0 mm High 35
18 Apr 16.3 °C 10 % 47 km/h 0.0 mm High 28
19 Apr 19.1 °C 6 % 84 km/h 0.0 mm Very high 41
20 Apr 9.2 °C 20 % 67 km/h 0.0 mm High 32
21 Apr 17.4 °C 18 % 35 km/h 0.0 mm High 23
22 Apr 18.1 °C 15 % 38 km/h 0.0 mm High 25
23 Apr 20.9 °C 13 % 41 km/h 0.0 mm High 27
24 Apr 21.5 °C 8 % 48 km/h 0.0 mm High 33
25 Apr 22.0 °C 9 % 46 km/h 0.0 mm High 34
26 Apr 21.7 °C 13 % 29 km/h 0.0 mm High 32
27 Apr 18.4 °C 20 % 46 km/h 0.3 mm High 32
28 Apr 19.3 °C 19 % 49 km/h 0.2 mm High 32
29 Apr 19.5 °C 10 % 64 km/h 0.0 mm Very high 40
30 Apr 15.6 °C 13 % 63 km/h 0.0 mm Very high 39
1 May 14.1 °C 14 % 64 km/h 0.7 mm High 32
2 May 8.9 °C 30 % 62 km/h 2.6 mm Low 6
3 May 12.5 °C 22 % 39 km/h 0.9 mm Low 7
4 May 19.9 °C 11 % 34 km/h 0.0 mm Moderate 20
5 May 21.1 °C 12 % 48 km/h 0.0 mm High 31
6 May 23.5 °C 11 % 42 km/h 0.0 mm High 34
7 May 23.8 °C 14 % 40 km/h 0.0 mm High 34
8 May 26.6 °C 8 % 45 km/h 0.0 mm Very high 40
9 May 26.3 °C 8 % 48 km/h 0.0 mm Very high 42
10 May after 25.7 °C 8 % 57 km/h 0.0 mm Very high 46
11 May after 23.7 °C 11 % 83 km/h 0.1 mm Extreme 58
12 May after 20.2 °C 11 % 71 km/h 0.0 mm Extreme 53
13 May after 18.9 °C 10 % 61 km/h 0.0 mm Very high 49
14 May after 20.2 °C 18 % 69 km/h 0.0 mm Very high 47
15 May after 22.1 °C 11 % 60 km/h 0.0 mm Very high 45
16 May after 24.2 °C 6 % 45 km/h 0.0 mm Very high 45
17 May after 22.9 °C 7 % 59 km/h 0.0 mm Extreme 50
18 May after 19.9 °C 7 % 51 km/h 0.0 mm Very high 48
19 May after 21.2 °C 7 % 41 km/h 0.0 mm Very high 46

Before and after, from space

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

Before · 4 Apr 2018
After · 16 May 2018

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 · 1,335Every 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 Rattlesnake Fire last?
The official perimeter only gives the start date (11 April 2018). The end comes from the heat detections inside the perimeter: it burned until 9 May 2018 (29 days from 11 April 2018), 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 11,079 hectares (110.8 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire entered 3 counties: Greenlee (9,008 ha, 1.9 %); Graham (1,412 ha, 0.1 %); Apache (723 ha, 0.0 %).
What was the weather like?
During the fire the temperature reached 26.6 °C, humidity dropped to 6 % and gusts hit 90 km/h. The fire danger index (FWI) reached 42, 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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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. 1,335 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.