Derre fire, 13 September 2021 Derre
The fire started on 13 September 2021 in Derre, Mozambique, and satellites saw it burning for 9 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 4,224 hectares from heat detections, spread across a single municipality.
It is the 479th largest in Zambézia since 2016 (of 842 with a page). Number 114 in Mozambique in 2021, of 233.
- Burnt area
- 4,224ha
- GWIS perimeter (Copernicus)
- Duration
- 9days
- 13 Sept 2021 – 21 Sept 2021
- Municipalities hit
- 1
- districts
- Started on
- 13 Sept
- 2021
- Heat detections
- 150
- in a single hotspot: 53 MW
- Danger at start
- 23
- High · FWI index
- Average daily power
- 276MW
- 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 one day without rain (1 mm or more) when it started. Rain came after the fire: 1.2 mm on 23 Sept.
This area had burned before
100% of the perimeter overlaps earlier fires recorded since 2016: 2,706 ha in 2016, 1,596 ha in 2017, 2,470 ha in 2018, 3,730 ha in 2019, 2,205 ha in 2020. Part of it burned more than once, so the yearly figures add up to more than the 4,209 ha that had burned before.
- 2,219 ha Mocuba fire, September 2018 116,289 ha in total; the hectares shown are those it shares with this fire
- 2,176 ha Derre fire, September 2019 10,860 ha in total; the hectares shown are those it shares with this fire
- 2,122 ha Derre fire, September 2016 116,560 ha in total; the hectares shown are those it shares with this fire
- 1,171 ha Morrumbala fire, September 2020 33,528 ha in total; the hectares shown are those it shares with this fire
- 820 ha Mocuba fire, September 2020 86,463 ha in total; the hectares shown are those it shares with this fire
- 66 ha Derre fire, September 2017 14,637 ha in total; the hectares shown are those it shares with this fire
What happened to each town
-
Derre where it started4,242 ha reached on 13 Sept0.9 %
Burnt area inside each municipality, from crossing the GWIS 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) |
|---|---|---|---|---|---|
| 13 Sept | 30.2 °C | 36 % | 37 km/h | 0.0 mm | High 23 |
| 14 Sept | 33.5 °C | 22 % | 34 km/h | 0.0 mm | High 36 |
| 15 Sept | 34.7 °C | 20 % | 35 km/h | 0.0 mm | Very high 39 |
| 16 Sept | 35.6 °C | 23 % | 34 km/h | 0.0 mm | High 38 |
| 17 Sept | 37.2 °C | 24 % | 50 km/h | 0.0 mm | Very high 47 |
| 18 Sept | 26.2 °C | 60 % | 46 km/h | 1.8 mm | Low 11 |
| 19 Sept | 26.2 °C | 42 % | 35 km/h | 1.1 mm | Moderate 14 |
| 20 Sept | 28.6 °C | 27 % | 26 km/h | 0.0 mm | High 26 |
| 21 Sept | 33.1 °C | 23 % | 37 km/h | 0.0 mm | Very high 39 |
| 22 Sept after | 27.2 °C | 45 % | 34 km/h | 0.9 mm | Moderate 20 |
| 23 Sept after | 26.2 °C | 52 % | 32 km/h | 1.2 mm | Moderate 12 |
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 · 150Every satellite heat detection, one by one, with time, satellite, power and coordinates.
| Date and time | Satellite | FRP (MW) | Lat | Lon |
|---|
Other fires nearby
- 116,560 haDerre2 September 2016 · 31 days · 5 km away
- 72,800 haDerre8 September 2025 · 33 days · 11 km away
- 47,144 haDerreSeptember 2022 · 20 days · 15 km away
- 72,301 haDerre21 August 2026 · 28 days · 19 km away
- 86,463 haMocuba13 September 2020 · 22 days · 21 km away
- 116,289 haMocuba2 September 2018 · 28 days · 40 km away
Frequently asked questions
- How long did the Derre fire last?
- GWIS (Copernicus) dates it between 13 September 2021 and 21 September 2021: 9 days between the first and last heat detection of the perimeter.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 4,224 hectares (42.2 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire only entered Derre (4,242 ha, 0.9 %).
- What was the weather like?
- During the fire the temperature reached 37.2 °C, humidity dropped to 20 % and gusts hit 50 km/h. The fire danger index (FWI) reached 47, class Very high.
- Where does this data come from?
- From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Mozambique (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.
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.
Report an error
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 3.0 Intergovernmental Organisations (CC BY 3.0 IGO)). 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.