How long did the Apple Fire last?

The official perimeter only gives the start date (31 July 2020). The end comes from the heat detections inside the perimeter: it burned until 12 August 2020 (13 days from 31 July 2020), 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 13,089 hectares (130.9 km²). Other tallies, such as daily incident reports, may give slightly different figures.

Which counties burned?

The fire entered 2 counties: Riverside (8,245 ha, 0.4 %); San Bernardino (4,844 ha, 0.1 %).

What was the weather like?

During the fire the temperature reached 33.3 °C, humidity dropped to 2 % and gusts hit 55 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.

US · United States · 2020-07-31 → 2020-08-12

Apple Fire, July 2020 Riverside, San Bernardino

Out · last detection 12 Aug 2020, 09:12 UTC

The fire started on 31 July 2020 in Riverside, United States, and satellites saw it burning for 13 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 13,089 hectares, spread across 2 counties.

It is the 79th largest in California since 2016 (of 442 with a page). Number 52 in United States in 2020, of 441.

Compare with…

Suggestions: Bogart · 2016 El Dorado · 2020 Manzanita · 2017 Rabbit · 2023

Burnt area: 13,089ha; official perimeter (MTBS / NIFC)
Duration: ≈ 13days; 31 Jul 2020 – 12 Aug 2020
Counties hit: 2; counties
Started on: 31 Jul; 2020
Heat detections: 1,036; in a single hotspot: 318 MW
Danger at start: 52; Extreme · FWI index
Average daily power: 2.7GW; detected power per day, on average

HOTSPOTS BY DAY 31 Jul12 Aug

Play back 12 Aug 2020

How it evolved, day by day

1 Aug 2 Aug 3 Aug 5 Aug 7 Aug 9 Aug 12 Aug

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

55km/h · peak gust

2%lowest humidity

It had gone 19 days without rain (1 mm or more) when it started. Rain came after the fire: 1.0 mm on 14 Aug.

This area had burned before

4% of the perimeter overlaps earlier fires recorded since 2016: 525 ha in 2016.

525 ha Bogart fire, August 2016 596 ha in total; the hectares shown are those it shares with this fire

How big is it?

It burned the equivalent of 8.3% of the area of London (131 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

Riverside where it started

8,245 ha reached on 1 Aug

0.4 %
San Bernardino

4,844 ha reached on 1 Aug

0.1 %

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 area3.8 ha

Residents≈ 150

Inside the perimeter there were about 3.8 hectares of built-up land and about 150 residents (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)
31 Jul	33.3 °C	16 %	53 km/h	0.0 mm	Extreme 52
1 Aug	33.0 °C	2 %	51 km/h	0.0 mm	Extreme 58
2 Aug	30.4 °C	12 %	48 km/h	0.0 mm	Extreme 53
3 Aug	30.3 °C	15 %	45 km/h	0.0 mm	Very high 48
4 Aug	27.5 °C	17 %	49 km/h	0.0 mm	Very high 47
5 Aug	26.2 °C	17 %	49 km/h	0.0 mm	Very high 46
6 Aug	24.9 °C	14 %	44 km/h	0.0 mm	Very high 44
7 Aug	26.7 °C	13 %	41 km/h	0.0 mm	Very high 42
8 Aug	28.0 °C	14 %	40 km/h	0.0 mm	Very high 42
9 Aug	29.1 °C	12 %	38 km/h	0.0 mm	Very high 41
10 Aug	29.4 °C	6 %	49 km/h	0.0 mm	Very high 50
11 Aug	29.1 °C	7 %	55 km/h	0.0 mm	Extreme 53
12 Aug	31.3 °C	4 %	41 km/h	0.4 mm	Extreme 50
13 Aug after	31.2 °C	16 %	37 km/h	0.0 mm	Very high 46
14 Aug after	33.4 °C	15 %	38 km/h	1.0 mm	High 35

Before and after, from space

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

↔

Before · 24 Jul 2020

After · 19 Aug 2020

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 · 1,036Every 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 Apple Fire last?: The official perimeter only gives the start date (31 July 2020). The end comes from the heat detections inside the perimeter: it burned until 12 August 2020 (13 days from 31 July 2020), 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 13,089 hectares (130.9 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?: The fire entered 2 counties: Riverside (8,245 ha, 0.4 %); San Bernardino (4,844 ha, 0.1 %).
What was the weather like?: During the fire the temperature reached 33.3 °C, humidity dropped to 2 % and gusts hit 55 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 · 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.

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.

Report an error

What do you think is wrong?

Dates or duration Place or towns Burned area Name It was not a wildfire Same fire as another page Something else

What really happened?

Your connection to the fire (optional) Email (optional)

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. 1,036 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.

Where it burned