How long did the La Sierra Fire last?

The official perimeter only gives the start date (16 May 2016). The end comes from the heat detections inside the perimeter: it burned until 21 May 2016 (13 days from 9 May 2016), 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 4,460 hectares (44.6 km²). Other tallies, such as daily incident reports, may give slightly different figures.

Which counties burned?

The fire only entered Santa Cruz (2,105 ha, 0.6 %).

What was the weather like?

During the fire the temperature reached 31.4 °C, humidity dropped to 7 % and gusts hit 67 km/h. The fire danger index (FWI) reached 73, class Very 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.

US · United States · 2016-05-09 → 2016-05-21

La Sierra Fire, May 2016 Santa Cruz

Out · last detection 21 May 2016, 10:04 UTC

The fire started on 9 May 2016 in Santa Cruz, United States, and satellites saw it burning for 13 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 4,460 hectares, spread across a single county.

It is the 77th largest in Arizona since 2016 (of 380 with a page). Number 76 in United States in 2016, of 475.

The power measured by the satellite is low (22.5 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: Alamo · 2021 Nogales · 2021 Tonto Canyon · 2022 Mule Ridge · 2016

Burnt area: 4,460ha; official perimeter (MTBS / NIFC)
Duration: ≈ 13days; 9 May 2016 – 21 May 2016
Counties hit: 1; counties
Started on: 9 May; 2016
Heat detections: 207; in a single hotspot: 23 MW
Danger at start: 38; High · FWI index
Average daily power: 134MW; detected power per day, on average

HOTSPOTS BY DAY 9 May21 May

Play back 21 May 2016

How it evolved, day by day

9 May 11 May 17 May 18 May 19 May 21 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

31°high

67km/h · peak gust

7%lowest humidity

It had gone 28 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?

It burned the equivalent of 2.8% of the area of London (45 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

Santa Cruz where it started

2,105 ha reached on 17 May

0.6 %

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 2015

Built-up area< 0.1 ha

Residents< 20

Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2015, 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)
9 May	23.0 °C	19 %	38 km/h	0.0 mm	High 38
10 May	26.0 °C	14 %	40 km/h	0.0 mm	Very high 44
11 May	28.6 °C	9 %	30 km/h	0.0 mm	Very high 43
12 May	31.3 °C	8 %	32 km/h	0.0 mm	Extreme 52
13 May	31.4 °C	8 %	48 km/h	0.0 mm	Extreme 59
14 May	29.6 °C	14 %	53 km/h	0.1 mm	Extreme 64
15 May	28.6 °C	7 %	67 km/h	0.0 mm	Very extreme 73
16 May	26.2 °C	16 %	62 km/h	0.0 mm	Extreme 64
17 May	24.6 °C	22 %	55 km/h	0.0 mm	Extreme 53
18 May	23.6 °C	18 %	37 km/h	0.0 mm	Very high 45
19 May	27.4 °C	17 %	35 km/h	0.0 mm	Very high 45
20 May	27.9 °C	12 %	55 km/h	0.0 mm	Extreme 57
21 May	25.4 °C	20 %	55 km/h	0.0 mm	Extreme 54
22 May after	26.3 °C	17 %	54 km/h	0.0 mm	Extreme 54
23 May after	26.0 °C	15 %	52 km/h	0.0 mm	Extreme 53
24 May after	25.7 °C	13 %	55 km/h	0.0 mm	Extreme 55
25 May after	25.7 °C	13 %	65 km/h	0.0 mm	Extreme 61
26 May after	23.1 °C	15 %	42 km/h	0.0 mm	Very high 49
27 May after	26.0 °C	10 %	37 km/h	0.0 mm	Very high 46
28 May after	28.0 °C	8 %	46 km/h	0.0 mm	Extreme 56
29 May after	28.6 °C	11 %	50 km/h	0.0 mm	Extreme 58
30 May after	27.7 °C	13 %	49 km/h	0.0 mm	Extreme 58
31 May after	27.4 °C	9 %	34 km/h	0.0 mm	Very high 48

Before and after, from space

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

↔

Before · 2 May 2016

After · 28 May 2016

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.

Detections table · 207Every 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 La Sierra Fire last?: The official perimeter only gives the start date (16 May 2016). The end comes from the heat detections inside the perimeter: it burned until 21 May 2016 (13 days from 9 May 2016), 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 4,460 hectares (44.6 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?: The fire only entered Santa Cruz (2,105 ha, 0.6 %).
What was the weather like?: During the fire the temperature reached 31.4 °C, humidity dropped to 7 % and gusts hit 67 km/h. The fire danger index (FWI) reached 73, class Very 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 · 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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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. 207 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 2015, 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