How long did the Greer Fire last?

The official perimeter only gives the start date (13 May 2025). The end comes from the heat detections inside the perimeter: it burned until 25 May 2025 (13 days from 13 May 2025), 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 8,218 hectares (82.2 km²). Other tallies, such as daily incident reports, may give slightly different figures.

Which counties burned?

The fire only entered Apache (8,105 ha, 0.3 %).

What was the weather like?

During the fire the temperature reached 24.9 °C, humidity dropped to 6 % and gusts hit 91 km/h. The fire danger index (FWI) reached 41, 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.

US · United States · 2025-05-13 → 2025-05-25

Greer Fire, May 2025 Apache

Out · last detection 25 May 2025, 21:17 UTC

The fire started on 13 May 2025 in Apache, United States, and satellites saw it burning for 13 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 8,218 hectares, spread across a single county.

It is the 40th largest in Arizona since 2016 (of 380 with a page). Number 50 in United States in 2025, of 327.

Compare with…

Suggestions: Whiting · 2019 Quemado · 2016 Boggy Creek · 2021 Ranch · 2022

Burnt area: 8,218ha; official perimeter (MTBS / NIFC)
Duration: ≈ 13days; 13 May 2025 – 25 May 2025
Counties hit: 1; counties
Started on: 13 May; 2025
Heat detections: 861; in a single hotspot: 360 MW
Danger at start: 34; High · FWI index
Average daily power: 1.9GW; detected power per day, on average

HOTSPOTS BY DAY 13 May25 May

Play back 25 May 2025

How it evolved, day by day

13 May 14 May 15 May 17 May 19 May 22 May 25 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

25°high

91km/h · peak gust

6%lowest humidity

It had gone 4 days without rain (1 mm or more) when it started. Rain came after the fire: 1.5 mm on 1 Jun.

This area had burned before

26% of the perimeter overlaps earlier fires recorded since 2016: 2,175 ha in 2021, 3 ha in 2023.

How big is it?

It burned the equivalent of 5.2% of the area of London (82 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

Apache where it started

8,105 ha reached on 13 May

0.3 %

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 2025

Built-up area2.4 ha

Residents≈ 50

Inside the perimeter there were about 2.4 hectares of built-up land and about 50 residents (GHSL 2025, 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. The GHSL 2025 epoch is a projection made from 2020 and earlier data.

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)
13 May	18.7 °C	18 %	91 km/h	0.0 mm	High 34
14 May	14.0 °C	15 %	68 km/h	0.0 mm	High 26
15 May	16.3 °C	14 %	53 km/h	0.0 mm	High 22
16 May	19.7 °C	9 %	49 km/h	0.0 mm	High 25
17 May	18.7 °C	14 %	64 km/h	0.0 mm	High 31
18 May	13.9 °C	25 %	73 km/h	0.0 mm	High 30
19 May	15.6 °C	17 %	77 km/h	0.0 mm	High 32
20 May	19.9 °C	8 %	40 km/h	0.0 mm	High 25
21 May	24.2 °C	7 %	45 km/h	0.0 mm	High 30
22 May	24.9 °C	6 %	55 km/h	0.0 mm	High 38
23 May	24.2 °C	6 %	58 km/h	0.0 mm	Very high 41
24 May	22.1 °C	6 %	56 km/h	0.0 mm	Very high 41
25 May	21.6 °C	8 %	53 km/h	0.0 mm	Very high 40
26 May after	21.9 °C	10 %	40 km/h	0.0 mm	High 38
27 May after	22.6 °C	10 %	32 km/h	0.1 mm	High 32
28 May after	24.6 °C	7 %	47 km/h	0.0 mm	Very high 40
29 May after	25.5 °C	8 %	40 km/h	0.0 mm	High 38
30 May after	25.8 °C	8 %	35 km/h	0.0 mm	High 35
31 May after	24.5 °C	13 %	30 km/h	0.2 mm	Very high 39
1 Jun after	24.5 °C	24 %	32 km/h	1.5 mm	Moderate 16

Before and after, from space

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

↔

Before · 6 May 2025

After · 1 Jun 2025

Before After

If the day is cloudy, change the date: each satellite passes once a day. In false colour the burnt ground looks brown or red.

The smoke

CAMS · Copernicus

On 16 May 2025 the air beside the fire reached 53 µg/m³ of PM2.5. That day averaged 22: 1.4 times the WHO daily guideline (15).

PM2.5 peak53 µg/m³

Days over the guideline2 days

PM1068 µg/m³

Optical depth0.30

WHO 15

111213141516

Good Fair Moderate Poor Very poor Extremely poor

Particles from the Copernicus CAMS model at the centre of the perimeter; these are not measurements in each town. The pale bar is the worst hour, the solid one the daily average.

Open-Meteo.com (CC BY 4.0) · Copernicus Atmosphere Monitoring Service (CAMS)

Detections table · 861Every 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 time	Satellite	FRP (MW)	Lat	Lon

Other fires nearby

All fires in United States ›

Frequently asked questions

How long did the Greer Fire last?: The official perimeter only gives the start date (13 May 2025). The end comes from the heat detections inside the perimeter: it burned until 25 May 2025 (13 days from 13 May 2025), 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 8,218 hectares (82.2 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?: The fire only entered Apache (8,105 ha, 0.3 %).
What was the weather like?: During the fire the temperature reached 24.9 °C, humidity dropped to 6 % and gusts hit 91 km/h. The fire danger index (FWI) reached 41, 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

NASA FIRMS ↗
NIFC · Fire maps ↗

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.

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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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What really happened?

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How we know this

Perimeter: NIFC WFIGS (United States), 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. 861 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 2025, 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.

Where it burned