How long did the Donnell fire last?

It burned between 2 August 2018 and 2 August 2018: 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 14,646 hectares (146.5 km²). Other tallies, such as daily incident reports, may give slightly different figures.

Which counties burned?

The fire entered 2 counties: Tuolumne (9,473 ha, 1.6 %); Alpine (5,201 ha, 2.7 %).

What was the weather like?

During the fire the temperature reached 33.2 °C, humidity dropped to 6 % and gusts hit 82 km/h. The fire danger index (FWI) reached 59, 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.

US · United States · 2018-08-02 → 2018-08-02

Donnell Fire, August 2018 Tuolumne, Alpine

Out · last detection 3 Aug 2018, 21:48 UTC

The fire started on 2 August 2018 in Tuolumne, United States, and satellites saw it burning for 1 day. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 14,646 hectares, spread across 2 counties.

It is the 75th largest in California since 2016 (of 442 with a page). Number 50 in United States in 2018, of 511.

Burnt area: 14,646ha; official perimeter (MTBS / NIFC)
Duration: 1day; 2 Aug 2018 – 2 Aug 2018
Municipalities hit: 2; counties
Started on: 2 Aug; 2018
Heat detections: 4,457; in a single hotspot: 447 MW
Danger at start: 32; High · FWI index
Energy released: 1.6GW; sum of detected power

Play back 3 Aug 2018

HOTSPOTS BY DAY 2 Aug2 Aug

How it evolved, day by day

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

The weather it burned in

33°high

82km/h · peak gust

6%lowest humidity

It had gone one day without rain (1 mm or more) when it started. Rain came after the fire: 1.2 mm on 2 Oct.

This area had burned before

1% of the perimeter overlaps earlier fires recorded since 2016: 126 ha in 2017.

126 ha Mccormick fire, August 2017 1,779 ha in total; the hectares shown are those it shares with this fire

What happened to each town

Tuolumne where it started

9,473 ha reached on 2 Aug

1.6 %
Alpine

5,201 ha reached on 4 Aug

2.7 %

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)
2 Aug	29.5 °C	18 %	48 km/h	0.0 mm	High 32
3 Aug after	28.9 °C	11 %	52 km/h	0.0 mm	Very high 41
4 Aug after	26.7 °C	17 %	68 km/h	0.0 mm	Very high 47
5 Aug after	27.5 °C	12 %	48 km/h	0.0 mm	Very high 39
6 Aug after	30.0 °C	13 %	28 km/h	0.0 mm	High 34
7 Aug after	31.7 °C	14 %	32 km/h	0.0 mm	High 37
8 Aug after	31.9 °C	14 %	37 km/h	0.0 mm	High 37
9 Aug after	33.2 °C	13 %	41 km/h	0.2 mm	Very high 42
10 Aug after	31.7 °C	10 %	34 km/h	0.2 mm	Very high 41
11 Aug after	31.5 °C	14 %	40 km/h	0.0 mm	Very high 43
12 Aug after	30.7 °C	16 %	46 km/h	0.0 mm	Very high 46
13 Aug after	30.3 °C	18 %	42 km/h	0.0 mm	Very high 42
14 Aug after	28.5 °C	24 %	41 km/h	2.7 mm	Moderate 12
15 Aug after	27.2 °C	25 %	39 km/h	2.0 mm	Moderate 14
16 Aug after	28.4 °C	23 %	46 km/h	0.3 mm	High 29
17 Aug after	28.5 °C	21 %	53 km/h	0.3 mm	High 34
18 Aug after	30.5 °C	15 %	41 km/h	0.0 mm	High 37
19 Aug after	31.2 °C	17 %	51 km/h	0.0 mm	Very high 41
20 Aug after	29.1 °C	14 %	53 km/h	0.0 mm	Very high 43
21 Aug after	26.5 °C	15 %	51 km/h	0.0 mm	Very high 43
22 Aug after	27.4 °C	13 %	45 km/h	0.0 mm	Very high 41
23 Aug after	27.2 °C	15 %	50 km/h	0.0 mm	Very high 42
24 Aug after	25.8 °C	13 %	55 km/h	0.0 mm	Very high 45
25 Aug after	26.4 °C	13 %	54 km/h	0.0 mm	Very high 45
26 Aug after	26.2 °C	16 %	59 km/h	0.0 mm	Very high 48
27 Aug after	25.4 °C	24 %	50 km/h	0.0 mm	Very high 40
28 Aug after	26.5 °C	23 %	31 km/h	1.1 mm	High 22
29 Aug after	26.4 °C	19 %	50 km/h	0.0 mm	High 36
30 Aug after	24.2 °C	10 %	55 km/h	0.0 mm	Very high 45
31 Aug after	25.2 °C	12 %	42 km/h	0.0 mm	Very high 39
1 Sept after	27.3 °C	16 %	32 km/h	0.0 mm	Very high 38
2 Sept after	28.8 °C	15 %	39 km/h	0.0 mm	Very high 41
3 Sept after	28.3 °C	15 %	34 km/h	0.0 mm	Very high 40
4 Sept after	27.4 °C	18 %	34 km/h	0.7 mm	High 32
5 Sept after	26.0 °C	26 %	35 km/h	0.1 mm	High 35
6 Sept after	27.2 °C	22 %	50 km/h	0.0 mm	Very high 38
7 Sept after	29.5 °C	18 %	50 km/h	0.0 mm	Very high 41
8 Sept after	27.9 °C	11 %	57 km/h	0.0 mm	Very high 48
9 Sept after	29.2 °C	7 %	46 km/h	0.0 mm	Very high 49
10 Sept after	28.1 °C	6 %	50 km/h	0.0 mm	Extreme 51
11 Sept after	25.2 °C	7 %	63 km/h	0.0 mm	Extreme 59
12 Sept after	19.3 °C	18 %	82 km/h	0.0 mm	Extreme 56
13 Sept after	17.9 °C	19 %	64 km/h	0.0 mm	Very high 46
14 Sept after	21.9 °C	17 %	64 km/h	0.0 mm	Very high 47
15 Sept after	19.7 °C	23 %	74 km/h	0.0 mm	Very high 46
16 Sept after	23.1 °C	11 %	50 km/h	0.0 mm	Very high 43
17 Sept after	23.8 °C	12 %	48 km/h	0.0 mm	Very high 42
18 Sept after	23.9 °C	13 %	48 km/h	0.0 mm	Very high 43
19 Sept after	23.0 °C	9 %	39 km/h	0.0 mm	Very high 42
20 Sept after	26.8 °C	11 %	27 km/h	0.0 mm	Very high 42
21 Sept after	26.3 °C	12 %	41 km/h	0.0 mm	Very high 43
22 Sept after	24.1 °C	13 %	55 km/h	0.0 mm	Very high 49
23 Sept after	23.0 °C	16 %	58 km/h	0.0 mm	Very high 49
24 Sept after	25.8 °C	10 %	26 km/h	0.0 mm	Very high 40
25 Sept after	26.7 °C	12 %	27 km/h	0.0 mm	Very high 41
26 Sept after	29.1 °C	11 %	30 km/h	0.0 mm	Very high 40
27 Sept after	29.5 °C	13 %	35 km/h	0.0 mm	Very high 43
28 Sept after	27.3 °C	13 %	43 km/h	0.0 mm	Very high 46
29 Sept after	19.9 °C	28 %	69 km/h	0.0 mm	Very high 44
30 Sept after	21.0 °C	20 %	58 km/h	0.0 mm	Very high 40
1 Oct after	21.4 °C	31 %	55 km/h	0.0 mm	High 36
2 Oct after	21.0 °C	32 %	48 km/h	1.2 mm	High 22

Before and after, from space

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

↔

Before · 26 Jul 2018

After · 9 Aug 2018

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 · 4,457Every 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 Donnell fire last?: It burned between 2 August 2018 and 2 August 2018: 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 14,646 hectares (146.5 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?: The fire entered 2 counties: Tuolumne (9,473 ha, 1.6 %); Alpine (5,201 ha, 2.7 %).
What was the weather like?: During the fire the temperature reached 33.2 °C, humidity dropped to 6 % and gusts hit 82 km/h. The fire danger index (FWI) reached 59, 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

NASA FIRMS ↗
NIFC · Fire maps ↗

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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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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