Dome Fire, September 2026 Mariposa
The fire started on 15 September 2026 in Mariposa, United States, and satellites saw it burning for 35 days. United States agencies (MTBS / NIFC) mapped an official burnt perimeter of 2,747 hectares, spread across a single county.
It is the 179th largest in California since 2016 (of 442 with a page). Number 149 in United States in 2026, of 423.
Compare with…
- Burnt area
- 2,747ha
- official perimeter (MTBS / NIFC)
- Duration
- ≈ 35days
- 15 Sept 2026 – 19 Oct 2026
- Counties hit
- 1
- counties
- Started on
- 15 Sept
- 2026
- Heat detections
- 1,075
- in a single hotspot: 410 MW
- Danger at start
- 26
- High · FWI index
- Average daily power
- 1.1GW
- detected power per day, on average
Where it burned
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
It had gone 16 days without rain (1 mm or more) when it started. Rain came after the fire: 2.4 mm on 20 Oct.
This area had burned before
53% of the perimeter overlaps earlier fires recorded since 2016: 1,447 ha in 2017.
How big is it?
London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).
Paris boundary: geoBoundaries · Institut national de l'information géographique et forestière (IGN-F) (Etalab Open License 2.0).
Madrid boundary: geoBoundaries · Open Data ESRI, IGN Central Registry of Cartography Area (CC BY 4.0).
Berlin boundary: geoBoundaries · Federal Agency for Cartography and Geodesy (dl-de/by-2-0).
This compares size, not location: both shapes are at the same scale, north up, centred on each other.
What happened to each county
-
Mariposa where it started2,801 ha reached on 15 Sept0.7 %
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 2025Inside the perimeter there was no noticeable built-up land and almost nobody lived there (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) · forecast models, provisional until the ERA5 reanalysis arrives
| Day | High | Min. humidity | Peak gust | Rain | Danger (FWI) |
|---|---|---|---|---|---|
| 15 Sept | 18.1 °C | 19 % | 43 km/h | 0.0 mm | High 26 |
| 16 Sept | 15.5 °C | 25 % | 42 km/h | 0.0 mm | High 25 |
| 17 Sept | 13.8 °C | 37 % | 45 km/h | 0.0 mm | Moderate 21 |
| 18 Sept | 15.4 °C | 24 % | 40 km/h | 0.0 mm | Moderate 21 |
| 19 Sept | 19.0 °C | 19 % | 37 km/h | 0.0 mm | High 23 |
| 20 Sept | 19.5 °C | 16 % | 46 km/h | 0.0 mm | High 28 |
| 21 Sept | 16.6 °C | 25 % | 27 km/h | 1.7 mm | Low 8 |
| 22 Sept | 17.2 °C | 31 % | 37 km/h | 0.9 mm | Low 11 |
| 23 Sept | 20.0 °C | 25 % | 43 km/h | 0.0 mm | Moderate 20 |
| 24 Sept | 20.4 °C | 22 % | 51 km/h | 0.0 mm | High 26 |
| 25 Sept | 17.2 °C | 34 % | 50 km/h | 0.0 mm | High 25 |
| 26 Sept | 16.8 °C | 27 % | 48 km/h | 0.0 mm | High 25 |
| 27 Sept | 14.8 °C | 30 % | 59 km/h | 0.0 mm | High 28 |
| 28 Sept | 12.3 °C | 34 % | 39 km/h | 6.6 mm | Very low 1 |
| 29 Sept | 19.5 °C | 17 % | 23 km/h | 0.0 mm | Low 5 |
| 30 Sept | 20.6 °C | 13 % | 35 km/h | 0.0 mm | Moderate 19 |
| 1 Oct | 22.8 °C | 13 % | 42 km/h | 0.0 mm | High 28 |
| 2 Oct | 22.2 °C | 14 % | 32 km/h | 0.0 mm | High 26 |
| 3 Oct | 22.8 °C | 16 % | 42 km/h | 0.0 mm | High 29 |
| 4 Oct | 22.4 °C | 18 % | 44 km/h | 0.0 mm | High 30 |
| 5 Oct | 21.0 °C | 23 % | 42 km/h | 0.8 mm | Moderate 21 |
| 6 Oct | 21.5 °C | 21 % | 43 km/h | 0.0 mm | High 25 |
| 7 Oct | 22.1 °C | 22 % | 44 km/h | 0.0 mm | High 27 |
| 8 Oct | 21.7 °C | 21 % | 42 km/h | 0.0 mm | High 26 |
| 9 Oct | 19.6 °C | 24 % | 47 km/h | 0.0 mm | High 28 |
| 10 Oct | 14.4 °C | 38 % | 49 km/h | 0.1 mm | High 24 |
| 11 Oct | 9.1 °C | 54 % | 60 km/h | 0.2 mm | Moderate 20 |
| 12 Oct | 4.0 °C | 61 % | 32 km/h | 4.1 mm | Very low 1 |
| 13 Oct | 9.3 °C | 20 % | 32 km/h | 0.0 mm | Very low 4 |
| 14 Oct | 14.4 °C | 14 % | 25 km/h | 0.0 mm | Low 9 |
| 15 Oct | 17.7 °C | 19 % | 49 km/h | 0.0 mm | Moderate 21 |
| 16 Oct | 20.2 °C | 10 % | 40 km/h | 0.0 mm | High 27 |
| 17 Oct | 17.6 °C | 12 % | 53 km/h | 0.0 mm | High 31 |
| 18 Oct | 15.5 °C | 17 % | 42 km/h | 0.0 mm | High 29 |
| 19 Oct | 13.0 °C | 30 % | 51 km/h | 0.0 mm | High 27 |
| 20 Oct after | 12.5 °C | 36 % | 49 km/h | 2.4 mm | Low 5 |
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
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 · CopernicusOn 22 September 2026 the air beside the fire reached 505 µg/m³ of PM2.5. That day averaged 316: 21 times the WHO daily guideline (15).
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 · 1,075Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 3,923 haEmpire MariposaAugust 2017 · 95 days · 4 km away
- 3,443 haRed MariposaAugust 2022 · 45 days · 11 km away
- 39,408 haFerguson MariposaJuly 2018 · 55 days · 17 km away
- 5,169 haRailroad MaderaAugust 2017 · 16 days · 19 km away
- 7,859 haOak MariposaJuly 2022 · 5 days · 25 km away
- 4,126 haRiver MaderaJuly 2021 · 3 days · 37 km away
Frequently asked questions
- How long did the Dome Fire last?
- The official perimeter only gives the start date (15 September 2026). The end comes from the heat detections inside the perimeter: it burned until 19 October 2026 (35 days from 15 September 2026), 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 2,747 hectares (27.5 km²). Other tallies, such as daily incident reports, may give slightly different figures.
- Which counties burned?
- The fire only entered Mariposa (2,801 ha, 0.7 %).
- Is the Dome Fire still active?
- No fire detections since 19 Oct 2026, 20:51 UTC. A lack of detections is not an official extinction.
- What was the weather like?
- During the fire the temperature reached 22.8 °C, humidity dropped to 10 % and gusts hit 60 km/h. The fire danger index (FWI) reached 31, class 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 ›
- NIFC · National Interagency Fire Center ↗
- InciWeb · Incident Information System ↗
- MTBS · Monitoring Trends in Burn Severity ↗
Satellite cross-check
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.
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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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. 1,075 Suomi-NPP VIIRS detections on those dates.
- We have not matched this page with any official record.
- Weather: ECMWF IFS model, provisional until the ERA5 reanalysis arrives.
- 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.
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.