Ashikaga fire, February 2021 足利市 · Ashikaga
The fire started on 23 February 2021 in Ashikaga, Japan, and satellites saw it burning for 3 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 226 hectares from heat detections, spread across a single municipality.
Number 9 in Japan in 2021, of 14.
The power measured by the satellite is low (7.0 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.
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- Burnt area
- 226ha
- GWIS perimeter (Copernicus)
- Duration
- 3days
- 23 Feb 2021 – 25 Feb 2021
- Municipalities hit
- 1
- municipalities
- Started on
- 23 Feb
- 2021
- Heat detections
- 12
- in a single hotspot: 7 MW
- Danger at start
- 12
- Moderate · FWI index
- Average daily power
- 11MW
- 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 7 days without rain (1 mm or more) when it started. Rain came after the fire: 10.1 mm on 2 Mar.
This area had burned before
No earlier perimeters overlap this fire since 2016, when the satellite record begins.
What happened to each town
-
227 ha reached on 23 Feb1.3 %
Burnt area inside each municipality, from crossing the GWIS 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 2020Inside the perimeter there were about 1.7 hectares of built-up land and about 40 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) |
|---|---|---|---|---|---|
| 23 Feb | 11.8 °C | 32 % | 63 km/h | 0.0 mm | Moderate 12 |
| 24 Feb | 9.2 °C | 26 % | 50 km/h | 0.0 mm | Low 10 |
| 25 Feb | 9.6 °C | 32 % | 38 km/h | 0.0 mm | Low 8 |
| 26 Feb after | 10.9 °C | 34 % | 28 km/h | 0.0 mm | Low 7 |
| 27 Feb after | 8.6 °C | 24 % | 31 km/h | 0.0 mm | Low 8 |
| 28 Feb after | 11.1 °C | 33 % | 27 km/h | 0.0 mm | Low 7 |
| 1 Mar after | 17.2 °C | 42 % | 34 km/h | 0.0 mm | Low 8 |
| 2 Mar after | 18.5 °C | 57 % | 55 km/h | 10.1 mm | Very low 0 |
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.
Detections table · 12Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
Frequently asked questions
- How long did the Ashikaga fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 23 February 2021 to 25 February 2021 (3 days). The perimeter dates it from 23 February 2021 to 24 February 2021.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 226 hectares (2.3 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered Ashikaga (227 ha, 1.3 %).
- What was the weather like?
- During the fire the temperature reached 11.8 °C, humidity dropped to 26 % and gusts hit 63 km/h. The fire danger index (FWI) reached 12, class Moderate.
- Where does this data come from?
- From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Japan (geoBoundaries). 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: 119 · Emergency number and official warnings ›
Satellite cross-check
History of this page · 1 Changes in area, dates, name, official record or merged pages, compared every night since 24 October 2026.
- Last day with fire: 24 February 2021 → 25 February 2021.
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
How we know this
- Perimeter: GWIS (Copernicus), rebuilt from heat detections rather than mapped on imagery.
- Dates adjusted with the VIIRS detections inside the perimeter, which said 23 February 2021 to 24 February 2021. 12 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.
Where this data comes from
The perimeter comes from the Copernicus Global Wildfire Information System (GWIS), which rebuilds it from MODIS and VIIRS heat detections and publishes it under CC BY 4.0. It is not measured on imagery as in Europe, so it is an estimate. Heat detections come from the VIIRS sensors aboard Suomi-NPP and NOAA-20, distributed by NASA FIRMS at 375 m resolution. Municipal boundaries come from geoBoundaries ADM2 (Creative Commons Attribution-ShareAlike 2.0). The area per municipality is computed by WorldFires by crossing the perimeter with those boundaries, so it may differ from each country’s official figure.