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Madre Fire, July 2025 San Luis Obispo

Out · last detection 3 Jul 2025, 20:47 UTC

The fire started on 2 July 2025 in San Luis Obispo, United States, and satellites saw it burning for 1 day. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 32,690 hectares, spread across a single county.

It is the 38th largest in California since 2016 (of 442 with a page). Number 9 in United States in 2025, of 327.

Burnt area
32,690ha
official perimeter (MTBS / NIFC)
Duration
1day
2 Jul 2025 – 2 Jul 2025
Municipalities hit
1
counties
Started on
2 Jul
2025
Heat detections
1,004
in a single hotspot: 428 MW
Danger at start
56
Extreme · FWI index
Energy released
14.5GW
sum of detected power

Where it burned

3 Jul 2025
HOTSPOTS BY DAY 2 Jul2 Jul

How it evolved, day by day

23

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

The weather it burned in

34°high
45km/h · peak gust
10%lowest humidity

It had gone 58 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.

What happened to each town

  1. San Luis Obispo where it started
    32,636 ha reached on 2 Jul
    3.8 %

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 Jul 32.2 °C 10 % 45 km/h 0.0 mm Extreme 56
3 Jul after 32.1 °C 18 % 42 km/h 0.0 mm Extreme 52
4 Jul after 29.2 °C 15 % 43 km/h 0.0 mm Extreme 52
5 Jul after 29.7 °C 16 % 34 km/h 0.0 mm Very high 48
6 Jul after 30.9 °C 12 % 36 km/h 0.0 mm Very high 49
7 Jul after 28.2 °C 23 % 40 km/h 0.0 mm Very high 46
8 Jul after 29.9 °C 17 % 35 km/h 0.0 mm Very high 43
9 Jul after 33.7 °C 12 % 33 km/h 0.0 mm Very high 49
10 Jul after 34.5 °C 7 % 30 km/h 0.0 mm Extreme 52
11 Jul after 35.1 °C 11 % 40 km/h 0.0 mm Extreme 57
12 Jul after 32.9 °C 17 % 34 km/h 0.0 mm Extreme 50
13 Jul after 34.3 °C 17 % 36 km/h 0.0 mm Extreme 52
14 Jul after 35.3 °C 15 % 38 km/h 0.0 mm Extreme 53
15 Jul after 30.1 °C 26 % 36 km/h 0.0 mm Very high 43
16 Jul after 28.1 °C 34 % 36 km/h 0.0 mm High 36
17 Jul after 29.5 °C 28 % 34 km/h 0.0 mm High 36
18 Jul after 32.0 °C 19 % 37 km/h 0.0 mm Very high 42
19 Jul after 33.1 °C 16 % 38 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 · 25 Jun 2025
After · 9 Jul 2025

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 4 July 2025 the air beside the fire reached 148 µg/m³ of PM2.5. That day averaged 78: 5.2 times the WHO daily guideline (15).

PM2.5 peak148 µg/m³
Days over the guideline2 days
PM10157 µg/m³
Optical depth1.23
3012345
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 · 1,004Every 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 Madre fire last?
It burned between 2 July 2025 and 2 July 2025: 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 32,690 hectares (326.9 km²). Other tallies, such as daily incident reports, may give slightly different figures.
Which counties burned?
The fire only entered San Luis Obispo (32,636 ha, 3.8 %).
What was the weather like?
During the fire the temperature reached 33.7 °C, humidity dropped to 10 % and gusts hit 45 km/h. The fire danger index (FWI) reached 56, 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

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.

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.