Burned area
satellite only2,464ha
Perimeter published by GWIS (Copernicus).
- Source
- GWIS (Copernicus)
- Date
- 3 Mar 2021 – 20 Mar 2021
+− cross-check
No official record is matched to this page to compare it with.
KH · Cambodia · –
Ou Ya Dav fire, March 2021 Ou Ya Dav
Out · last detection 20 Mar 2021, 19:01 UTC
The fire started on 3 March 2021 in Ou Ya Dav, Cambodia, and satellites saw it burning for 18 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 2,464 hectares from heat detections, spread across a single municipality.
It is the 33th largest in Ratanakiri since 2016 (of 62 with a page). Number 33 in Cambodia in 2021, of 69.
Use this data
Compare with…
Use this data
Fire page data · version 2026-10-27matches the official recordwith caveatssatellite onlymodel
When copying, the sentence is
Tick the figures you want: they make up the lede and the CSV.
Duration by satellite
satellite only18days
3 Mar 2021 to 20 Mar 2021: first and last day with fire on the page.
- Source
- GWIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- last detection: 20 Mar 2021, 19:01 UTC
+− cross-check
Satellites pass a few times a day and cloud or smoke can hide the fire: a lack of detections is not an official extinction. Each country’s emergency service declares a fire contained or out.
Start
satellite only3 Mar 2021
First day with fire seen by the satellites or the perimeter.
- Source
- GWIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- 3 Mar 2021
+− cross-check
No official record is matched to this page, so the alert time and the cause are not known here.
Hotspots
satellite only182
VIIRS detections at 375 m. Most intense hotspot: 83 MW.
- Source
- NASA FIRMS · VIIRS (Suomi NPP)
- Date
- 3 Mar 2021 – 20 Mar 2021
+− cross-check
There is no official record to compare with. Each hotspot is a pixel detected in one satellite pass, not a separate fire.
The worst day
satellite only530MW
Total radiative power on 8 March 2021; hotspots that day: 26.
- Source
- NASA FIRMS · VIIRS (FRP)
- Date
- 8 Mar 2021
+− cross-check
Fire radiative power (FRP) measures the energy the fire gives off when the satellite passes. Added up by day, it compares intensity, not area.
Danger at the start
model34.0FWI · high
Fire Weather Index (Canadian system) computed by WorldFires for the day the fire started. Consecutive days without rain before: 20.
- Source
- WorldFires calculation (Canadian FWI system)
- Date
- 3 Mar 2021, local noon
- Model
- ERA5 0,25° (ECMWF · Copernicus C3S) · Open-Meteo.com
+− cross-check
This is an index computed from weather model data, not a measurement of the fire nor an official warning. Danger warnings are issued by each country’s authority. Emergency number and official warnings
Weather during the fire
model37.4°C · 27% RH
High of 37.4 °C and minimum humidity of 27% on 18 March 2021; gusts of 47 km/h on 3 March 2021.
- Source
- weather model at the fire’s grid cell
- Date
- 3 Mar 2021 – 20 Mar 2021
- Model
- ERA5 0,25° (ECMWF · Copernicus C3S) · Open-Meteo.com
+− cross-check
These are model values for a cell of about 25 km, not from a weather station: they may differ from what was measured on the ground.
This page’s change log has been kept since 24 October 2026: every night what it publishes is compared and the difference is logged. Anything earlier is reconstructed from each source’s date and marked as reconstructed.
Show
-
· reconstructed weatherWeather and FWI computed from the ERA5 reanalysis
-
logLast day with fire: 13 March 2021 → 20 March 2021.
-
· reconstructed GHSLPopulation and built-up area computed
What was saved on 27 October 2026
Every night a snapshot of what the page shows is saved. If anything changes, it appears in the list as a log entry.
- Area
- 2,464 ha
- Dates
- 3 Mar 2021 – 20 Mar 2021
- Name
- Ou Ya Dav
- Official record
- —
Versioned permanent link
https://worldfires.org/en/fire/ou-ya-dav-2021-03?v=2026-10-27A version keeps the area, dates, name and official record; the area as it was logged (changes under 2% are not logged). The map, hotspots and weather always show today’s data.
Citation
A lede of about 60 words figures only, no adjectives
CSV for this fire ou-ya-dav-2021-03.csv · daily, no individual hotspots
| fecha | focos_viirs | frp_mw | tmax_c | tmin_c | hr_min_pct | viento_max_kmh | racha_max_kmh | precip_mm | fwi | clase_fwi | dentro_del_incendio |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2021-03-03 | 30 | 138 | 34.3 | 23.8 | 37 | 18.8 | 47.2 | 0 | 34 | alto | 1 |
| 2021-03-04 | 38 | 509 | 35.5 | 23.4 | 34 | 14.7 | 37.1 | 0 | 31.3 | alto | 1 |
| 2021-03-05 | 8 | 61 | 36.8 | 22.8 | 25 | 14.3 | 31.7 | 0 | 37 | alto | 1 |
| 2021-03-06 | 1 | 8 | 37.2 | 23.2 | 25 | 10.1 | 20.2 | 0 | 34.3 | alto | 1 |
| 2021-03-07 | 8 | 28 | 36.1 | 23.6 | 31 | 16.6 | 40 | 0 | 40.5 | muy_alto | 1 |
| 2021-03-08 | 26 | 530 | 34 | 23.4 | 37 | 16.3 | 39.6 | 0.1 | 36.4 | alto | 1 |
| 2021-03-09 | 23 | 260 | 34.8 | 22.2 | 31 | 15.3 | 40 | 0 | 35.9 | alto | 1 |
| 2021-03-10 | 1 | 6 | 34.6 | 22.3 | 32 | 16.3 | 38.2 | 0 | 37.1 | alto | 1 |
| 2021-03-11 | 4 | 4 | 35.5 | 22.9 | 33 | 16 | 41.4 | 0 | 37.1 | alto | 1 |
| 2021-03-12 | 6 | 25 | 34.9 | 22.9 | 31 | 17.3 | 44.6 | 0 | 38.7 | muy_alto | 1 |
| 2021-03-13 | 9 | 57 | 36 | 22.1 | 25 | 16.6 | 37.4 | 0 | 40.4 | muy_alto | 1 |
| 2021-03-14 | 9 | 42 | 35.2 | 23 | 28 | 16.6 | 39.6 | 0 | 40.8 | muy_alto | 1 |
| 2021-03-15 | 0 | 0 | 35.3 | 22.1 | 31 | 14.8 | 31.3 | 0 | 39.3 | muy_alto | 1 |
| 2021-03-16 | 5 | 46 | 35.2 | 23.8 | 33 | 13.3 | 25.9 | 0 | 37.6 | alto | 1 |
| 2021-03-17 | 6 | 49 | 35.8 | 23.1 | 27 | 11.2 | 24.8 | 0 | 36 | alto | 1 |
| 2021-03-18 | 2 | 8 | 37.4 | 24.1 | 27 | 15.9 | 36 | 0 | 40.6 | muy_alto | 1 |
| 2021-03-19 | 2 | 19 | 37.2 | 24.3 | 34 | 14.1 | 28.8 | 0 | 39.2 | muy_alto | 1 |
| 2021-03-20 | 4 | 3 | 37.1 | 25.9 | 39 | 10.8 | 27.4 | 0.4 | 33.6 | alto | 1 |
| 2021-03-21 | 0 | 0 | 35.6 | 26.6 | 33 | 17.7 | 41.8 | 0.1 | 40 | muy_alto | 0 |
| 2021-03-22 | 0 | 0 | 33.4 | 25.4 | 37 | 24.9 | 61.9 | 0 | 45.8 | muy_alto | 0 |
| 2021-03-23 | 0 | 0 | 33.3 | 23.8 | 36 | 22.6 | 56.9 | 0 | 43.7 | muy_alto | 0 |
| 2021-03-24 | 0 | 0 | 34.4 | 22.7 | 41 | 18.2 | 45.4 | 0 | 37.4 | alto | 0 |
| 2021-03-25 | 0 | 0 | 35.9 | 23.7 | 35 | 16.5 | 40.3 | 0 | 36.1 | alto | 0 |
| 2021-03-26 | 0 | 0 | 37.1 | 23.5 | 32 | 15.1 | 36.7 | 0 | 36.2 | alto | 0 |
| 2021-03-27 | 0 | 0 | 37.6 | 24.6 | 27 | 15.2 | 32.4 | 0 | 39.9 | muy_alto | 0 |
| 2021-03-28 | 0 | 0 | 37.9 | 24.5 | 28 | 8.2 | 19.1 | 0 | 33.9 | alto | 0 |
| 2021-03-29 | 0 | 0 | 37.3 | 25.9 | 32 | 9.8 | 24.1 | 0 | 35.4 | alto | 0 |
| 2021-03-30 | 0 | 0 | 37 | 26.7 | 33 | 9.6 | 28.8 | 0 | 35.5 | alto | 0 |
It is generated in your browser from this page’s data: one file per fire, aggregated by day and without individual hotspots.
Live widget for your story
It updates itself while the fire is still active and links to this page. Free, with the attribution shown at the bottom.
Sources for this page: GWIS (Copernicus), NASA FIRMS (VIIRS), ERA5 (ECMWF/Copernicus C3S) · Open-Meteo.com (CC BY 4.0), GHSL (JRC). Open-Meteo.com · How we build fire pages: methodology
- Burnt area
- 2,464ha
- GWIS perimeter (Copernicus)
- Duration
- 18days
- 3 Mar 2021 – 20 Mar 2021
- Municipalities hit
- 1
- districts
- Started on
- 3 Mar
- 2021
- Heat detections
- 182
- in a single hotspot: 83 MW
- Danger at start
- 34
- High · FWI index
- Average daily power
- 106MW
- detected power per day, on average
Where it burned
HOTSPOTS BY DAY
3 Mar20 Mar
20 Mar 2021
How it evolved, day by day
3 Mar
8 Mar
11 Mar
16 Mar
20 Mar
Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.
The weather it burned in
37°high
47km/h · peak gust
25%lowest humidity
It had gone 20 days without rain (1 mm or more) when it started.
This area had burned before
94% of the perimeter overlaps earlier fires recorded since 2016: 71 ha in 2016, 2,127 ha in 2019, 1,802 ha in 2020. Part of it burned more than once, so the yearly figures add up to more than the 2,324 ha that had burned before.
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 town
-
Ou Ya Dav where it started2,479 ha reached on 3 Mar1.5 %
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 2020Built-up area< 0.1 ha
Residents< 20
Inside the perimeter there was no noticeable built-up land and almost nobody lived there (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) |
|---|---|---|---|---|---|
| 3 Mar | 34.3 °C | 37 % | 47 km/h | 0.0 mm | High 34 |
| 4 Mar | 35.5 °C | 34 % | 37 km/h | 0.0 mm | High 31 |
| 5 Mar | 36.8 °C | 25 % | 32 km/h | 0.0 mm | High 37 |
| 6 Mar | 37.2 °C | 25 % | 20 km/h | 0.0 mm | High 34 |
| 7 Mar | 36.1 °C | 31 % | 40 km/h | 0.0 mm | Very high 40 |
| 8 Mar | 34.0 °C | 37 % | 40 km/h | 0.1 mm | High 36 |
| 9 Mar | 34.8 °C | 31 % | 40 km/h | 0.0 mm | High 36 |
| 10 Mar | 34.6 °C | 32 % | 38 km/h | 0.0 mm | High 37 |
| 11 Mar | 35.5 °C | 33 % | 41 km/h | 0.0 mm | High 37 |
| 12 Mar | 34.9 °C | 31 % | 45 km/h | 0.0 mm | Very high 39 |
| 13 Mar | 36.0 °C | 25 % | 37 km/h | 0.0 mm | Very high 40 |
| 14 Mar | 35.2 °C | 28 % | 40 km/h | 0.0 mm | Very high 41 |
| 15 Mar | 35.3 °C | 31 % | 31 km/h | 0.0 mm | Very high 39 |
| 16 Mar | 35.2 °C | 33 % | 26 km/h | 0.0 mm | High 38 |
| 17 Mar | 35.8 °C | 27 % | 25 km/h | 0.0 mm | High 36 |
| 18 Mar | 37.4 °C | 27 % | 36 km/h | 0.0 mm | Very high 41 |
| 19 Mar | 37.2 °C | 34 % | 29 km/h | 0.0 mm | Very high 39 |
| 20 Mar | 37.1 °C | 39 % | 27 km/h | 0.4 mm | High 34 |
| 21 Mar after | 35.6 °C | 33 % | 42 km/h | 0.1 mm | Very high 40 |
| 22 Mar after | 33.4 °C | 37 % | 62 km/h | 0.0 mm | Very high 46 |
| 23 Mar after | 33.3 °C | 36 % | 57 km/h | 0.0 mm | Very high 44 |
| 24 Mar after | 34.4 °C | 41 % | 45 km/h | 0.0 mm | High 37 |
| 25 Mar after | 35.9 °C | 35 % | 40 km/h | 0.0 mm | High 36 |
| 26 Mar after | 37.1 °C | 32 % | 37 km/h | 0.0 mm | High 36 |
| 27 Mar after | 37.6 °C | 27 % | 32 km/h | 0.0 mm | Very high 40 |
| 28 Mar after | 37.9 °C | 28 % | 19 km/h | 0.0 mm | High 34 |
| 29 Mar after | 37.3 °C | 32 % | 24 km/h | 0.0 mm | High 35 |
| 30 Mar after | 37.0 °C | 33 % | 29 km/h | 0.0 mm | High 36 |
Its twins: fires that started in the same weather
It started with an FWI of 34.0, a minimum humidity of 37% and 20 days without rain. Fires in the area that started in weather like this since 2016: 36.
FWI at the start
34.0
Minimum humidity
37 %
Days without rain
20
this fire
chosen twins
rest of the area
Almost identicalSimilar
Outlines of the closest twins
This fire · Ou Ya Dav fire, March 2021
2,464 ha
18 days
FWI 34.0
Min. humidity 37 %
Sesan fire, April 2016
3,965 ha
32 days
FWI 35.2
Min. humidity 37 %
113 km away, in 2016
First rain (1 mm or more) after it ended: 1.5 mm on 17 May.
Kaoh Nheaek fire, January 2021
2,225 ha
17 days
FWI 33.3
Min. humidity 38 %
70 km away, in 2021
First rain (1 mm or more) after it ended: 1.9 mm on 10 Feb.
Koun Mom fire, January 2019
3,843 ha
34 days
FWI 31.4
Min. humidity 37 %
71 km away, in 2019
First rain (1 mm or more) after it ended: none in the following ten days.
Ou Ya Dav fire, January 2016
4,948 ha
22 days
FWI 33.3
Min. humidity 33 %
37 km away, in 2016
First rain (1 mm or more) after it ended: none in the following ten days.
Sa Thay fire, February 2016
1,345 ha
15 days
FWI 31.3
Min. humidity 38 %
60 km away, in 2016
First rain (1 mm or more) after it ended: none in the following ten days.
What happened to them
- 16 days
- median duration
- 2,774 ha
- median area
- 100 %
- went past 1,000 ha
- 1.5 mm
- rain at the end (median; 11 of 36 had it)
It burned an area similar to its twins (2,464 ha against a median of 2,774 ha) and lasted 18 days, against 16 days.
In 25 of 36, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 1.5 mm.
This is a bank of analogues: it shows what usually happens, not what will happen. With fewer than 15 twins we give no figures. How we calculate it
How it ended
—first rain
—no rain in ten days
47km/h · max. gust
It was considered over on 20 Mar, and not even 1 mm fell in the following ten days: it went out without rain. Twins with rain when they ended: 11 of 36, with a median of 1.5 mm.
Weather on this page: Open-Meteo.com (CC BY 4.0) · Copernicus Climate Change Service (ERA5)
How a twin is chosen
- Same area: fires that have already ended, less than 250 km from this one, since 2016.
- Same start: we compare the FWI on the first day, the minimum humidity that day and the run of days without rain before it. The slider sets how much they may differ.
- Only pages with final weather data (ERA5 reanalysis) calculated in the same way as this fire’s; agricultural and grass burns and pages with data under review are left out.
- Fires burning at the same time as this one (a week before or after) are left out: they share the same spell of weather and do not count as a precedent.
- They are sorted by similarity, and the outlines of the first five are drawn.
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
↔
Before · 24 Feb 2021
After · 27 Mar 2021
Sentinel-2 did not pass over on that day. Try another date, or use false colour, which is daily.
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 · 182Every 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
- 5,030 haOu Ya DavMarch 2020 · 14 days · 2 km away
- 3,725 haOu Ya DavJanuary 2026 · 23 days · 30 km away
- 5,212 haLumphatFebruary 2017 · 17 days · 34 km away
- 3,860 haLumphatJanuary 2019 · 16 days · 34 km away
- 4,949 haOu Ya Dav14 January 2016 · 22 days · 37 km away
- 4,672 haLumphat23 January 2016 · 25 days · 38 km away
Frequently asked questions
- How long did the Ou Ya Dav fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 3 March 2021 to 20 March 2021 (18 days). The perimeter dates it from 3 March 2021 to 13 March 2021.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 2,464 hectares (24.6 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered Ou Ya Dav (2,479 ha, 1.5 %).
- What was the weather like?
- During the fire the temperature reached 37.4 °C, humidity dropped to 25 % and gusts hit 47 km/h. The fire danger index (FWI) reached 41, class Very high.
- Where does this data come from?
- From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Cambodia (geoBoundaries). It is not an official report.
- How did the fires that started in similar weather in this area end?
- Fires less than 250 km away that started since 2016 with a similar FWI, humidity and dry spell: 36. Their median duration was 16 days and their median area 2,774 ha; 100 % went past 1,000 ha. In 25 of 36, not even 1 mm fell in the ten days after the end: they went out without rain. In the rest, the first rainy day brought a median of 1.5 mm.
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.
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: 13 March 2021 → 20 March 2021.
RSS Changes to this page With cross-checks and a citable version
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 3 March 2021 to 13 March 2021. 182 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 4.0 International (CC BY 4.0)). 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.