Yoni fire, 14 April 2026 Yoni, Masimera
The fire started on 14 April 2026 in Yoni, Sierra Leone, and satellites saw it burning for 20 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 4,535 hectares from heat detections, spread across 2 municipalities.
It is the 36th largest in Northern since 2016 (of 1112 with a page). Number 20 in Sierra Leone in 2026, of 305.
- Burnt area
- 4,535ha
- GWIS perimeter (Copernicus)
- Duration
- 20days
- 14 Apr 2026 – 3 May 2026
- Municipalities hit
- 2
- chiefdoms
- Started on
- 14 Apr
- 2026
- Heat detections
- 95
- in a single hotspot: 139 MW
- Danger at start
- 9
- Low · FWI index
- Energy released
- 1.5GW
- sum of detected power
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 2 days without rain (1 mm or more) when it started. Rain came after the fire: 1.6 mm on 5 May.
This area had burned before
42% of the perimeter overlaps earlier fires recorded since 2016: 134 ha in 2017, 1,293 ha in 2018, 475 ha in 2023.
- 1,293 ha Yoni fire, April 2018 4,358 ha in total; the hectares shown are those it shares with this fire
- 475 ha Masimera fire, April 2023 1,122 ha in total; the hectares shown are those it shares with this fire
- 134 ha Masimera fire, April 2017 4,665 ha in total; the hectares shown are those it shares with this fire
What happened to each town
-
Yoni where it started4,109 ha reached on 14 Apr3.3 %
-
455 ha reached on 14 Apr0.7 %
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) |
|---|---|---|---|---|---|
| 14 Apr | 34.2 °C | 55 % | 28 km/h | 1.5 mm | Low 9 |
| 15 Apr | 36.0 °C | 46 % | 22 km/h | 0.4 mm | Moderate 17 |
| 16 Apr | 33.2 °C | 56 % | 32 km/h | 1.4 mm | Low 10 |
| 17 Apr | 34.9 °C | 45 % | 28 km/h | 0.0 mm | Moderate 18 |
| 18 Apr | 36.0 °C | 40 % | 32 km/h | 0.0 mm | High 24 |
| 19 Apr | 35.4 °C | 41 % | 28 km/h | 0.0 mm | High 24 |
| 20 Apr | 34.6 °C | 49 % | 31 km/h | 3.7 mm | Low 6 |
| 21 Apr | 34.9 °C | 42 % | 31 km/h | 0.0 mm | Moderate 19 |
| 22 Apr | 35.4 °C | 44 % | 30 km/h | 1.2 mm | Moderate 17 |
| 23 Apr | 34.6 °C | 35 % | 35 km/h | 0.0 mm | High 26 |
| 24 Apr | 34.1 °C | 34 % | 36 km/h | 0.0 mm | High 28 |
| 25 Apr | 35.8 °C | 37 % | 33 km/h | 0.0 mm | High 28 |
| 26 Apr | 34.1 °C | 42 % | 32 km/h | 0.0 mm | High 27 |
| 27 Apr | 34.6 °C | 44 % | 29 km/h | 0.0 mm | High 27 |
| 28 Apr | 35.6 °C | 37 % | 33 km/h | 0.0 mm | High 29 |
| 29 Apr | 34.9 °C | 32 % | 28 km/h | 0.0 mm | High 29 |
| 30 Apr | 35.8 °C | 42 % | 20 km/h | 0.0 mm | High 28 |
| 1 May | 36.6 °C | 37 % | 32 km/h | 0.1 mm | High 30 |
| 2 May | 35.6 °C | 44 % | 32 km/h | 0.3 mm | High 29 |
| 3 May | 34.1 °C | 57 % | 28 km/h | 5.2 mm | Low 6 |
| 4 May after | 35.2 °C | 49 % | 30 km/h | 0.6 mm | Moderate 15 |
| 5 May after | 32.8 °C | 57 % | 32 km/h | 1.6 mm | Low 10 |
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 21 April 2026 the air beside the fire reached 69 µg/m³ of PM2.5. That day averaged 49: 3.3 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 · 95Every 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 Yoni fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 14 April 2026 to 3 May 2026 (20 days). The perimeter dates it from 14 April 2026 to 27 April 2026.
- How much area did it burn?
- The perimeter GWIS (Copernicus) rebuilt from heat detections is 4,535 hectares (45.4 km²). It is an estimate: official national figures may differ.
- Which municipalities burned?
- The fire entered 2 municipalities: Yoni (4,109 ha, 3.3 %); Masimera (455 ha, 0.7 %).
- What was the weather like?
- During the fire the temperature reached 36.6 °C, humidity dropped to 32 % and gusts hit 36 km/h. The fire danger index (FWI) reached 30, class High.
- Where does this data come from?
- From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Sierra Leone (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 ADM3 (Creative Commons Attribution 4.0 (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.