How long did the Nyasa fire last?

According to the heat detections seen by satellite inside the perimeter, it burned from 4 September 2025 to 21 September 2025 (18 days). The perimeter dates it from 8 September 2025 to 21 September 2025.

How much area did it burn?

The perimeter GWIS (Copernicus) rebuilt from heat detections is 3,615 hectares (36.2 km²). It is an estimate: official national figures may differ.

Which municipalities burned?

The fire only entered Nyasa (3,465 ha, 1.1 %).

What was the weather like?

During the fire the temperature reached 32.2 °C, humidity dropped to 28 % and gusts hit 48 km/h. The fire danger index (FWI) reached 36, class High.

Where does this data come from?

From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Tanzania (geoBoundaries). It is not an official report.

TZ · Tanzania · 2025-09-04 → 2025-09-21

Nyasa fire, 4 September 2025 Nyasa

Out · last detection 21 Sept 2025, 10:26 UTC

The fire started on 4 September 2025 in Nyasa, Tanzania, and satellites saw it burning for 18 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 3,615 hectares from heat detections, spread across a single municipality.

It is the 59th largest in Ruvuma since 2016 (of 94 with a page). Number 113 in Tanzania in 2025, of 161.

Compare with…

Suggestions: Nyasa · 2017 Nyasa · 2019 Sanga · 2022

Burnt area: 3,615ha; GWIS perimeter (Copernicus)
Duration: 18days; 4 Sept 2025 – 21 Sept 2025
Municipalities hit: 1; districts
Started on: 4 Sept; 2025
Heat detections: 82; in a single hotspot: 79 MW
Danger at start: 36; High · FWI index
Average daily power: 43MW; detected power per day, on average

HOTSPOTS BY DAY 4 Sept21 Sept

Play back 21 Sept 2025

How it evolved, day by day

4 Sept 7 Sept 8 Sept 10 Sept 13 Sept 16 Sept 21 Sept

Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.

The weather it burned in

32°high

48km/h · peak gust

28%lowest humidity

It had gone 40 days without rain (1 mm or more) when it started.

This area had burned before

15% of the perimeter overlaps earlier fires recorded since 2016: 397 ha in 2016, 130 ha in 2017.

How big is it?

It burned the equivalent of 2.3% of the area of London (36 km² against 1,583 km²).

London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).

This compares size, not location: both shapes are at the same scale, north up, centred on each other.

What happened to each town

Nyasa where it started

3,465 ha reached on 4 Sept

1.1 %

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 2025

Built-up area< 0.1 ha

Residents< 20

Inside 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) · Copernicus Climate Change Service (ERA5)

Day	High	Min. humidity	Peak gust	Rain	Danger (FWI)
8 Sept	31.3 °C	28 %	37 km/h	0.0 mm	High 36
9 Sept	30.3 °C	39 %	36 km/h	0.1 mm	High 31
10 Sept	31.1 °C	33 %	43 km/h	0.0 mm	High 34
11 Sept	30.0 °C	31 %	43 km/h	0.0 mm	High 34
12 Sept	29.7 °C	31 %	38 km/h	0.0 mm	High 33
13 Sept	30.5 °C	30 %	37 km/h	0.0 mm	High 32
14 Sept	31.2 °C	32 %	27 km/h	0.0 mm	High 30
15 Sept	30.4 °C	39 %	28 km/h	0.1 mm	High 29
16 Sept	31.7 °C	32 %	28 km/h	0.0 mm	High 29
17 Sept	32.0 °C	31 %	35 km/h	0.0 mm	High 31
18 Sept	31.1 °C	38 %	38 km/h	0.2 mm	High 34
19 Sept	32.2 °C	35 %	41 km/h	0.3 mm	High 34
20 Sept	29.5 °C	38 %	48 km/h	0.0 mm	High 36
21 Sept	30.7 °C	36 %	46 km/h	0.0 mm	High 36
22 Sept after	30.3 °C	39 %	44 km/h	0.0 mm	High 35
23 Sept after	31.0 °C	32 %	40 km/h	0.0 mm	High 33
24 Sept after	29.7 °C	37 %	40 km/h	0.0 mm	High 33
25 Sept after	31.0 °C	31 %	36 km/h	0.0 mm	High 32
26 Sept after	30.4 °C	32 %	42 km/h	0.0 mm	High 34
27 Sept after	31.2 °C	31 %	42 km/h	0.0 mm	High 36
28 Sept after	32.0 °C	30 %	36 km/h	0.0 mm	High 33
29 Sept after	33.7 °C	28 %	37 km/h	0.0 mm	High 36
30 Sept after	33.1 °C	35 %	39 km/h	0.0 mm	High 37
1 Oct after	29.5 °C	46 %	45 km/h	0.8 mm	High 26

Before and after, from space

Drag the line to compare the same ground before the fire and after it.

↔

Before · 28 Aug 2025

After · 28 Sept 2025

Before After

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 · Copernicus

On 8 September 2025 the air beside the fire reached 76 µg/m³ of PM2.5. That day averaged 41: 2.8 times the WHO daily guideline (15).

PM2.5 peak76 µg/m³

Days over the guideline14 days

PM1078 µg/m³

Optical depth0.80

WHO 15

6789101112131415161718192021222324

Good Fair Moderate Poor Very poor Extremely poor

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 · 82Every 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

All fires in Tanzania ›

Frequently asked questions

How long did the Nyasa fire last?: According to the heat detections seen by satellite inside the perimeter, it burned from 4 September 2025 to 21 September 2025 (18 days). The perimeter dates it from 8 September 2025 to 21 September 2025.
How much area did it burn?: The perimeter GWIS (Copernicus) rebuilt from heat detections is 3,615 hectares (36.2 km²). It is an estimate: official national figures may differ.
Which municipalities burned?: The fire only entered Nyasa (3,465 ha, 1.1 %).
What was the weather like?: During the fire the temperature reached 32.2 °C, humidity dropped to 28 % and gusts hit 48 km/h. The fire danger index (FWI) reached 36, class High.
Where does this data come from?: From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Tanzania (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: 112 · Emergency number and official warnings ›

Satellite cross-check

NASA FIRMS ↗
GWIS · Copernicus ↗

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.

RSS Changes to this page

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

What do you think is wrong?

Dates or duration Place or towns Burned area Name It was not a wildfire Same fire as another page Something else

What really happened?

Your connection to the fire (optional) Email (optional)

We will only use your email to reply about this report. Privacy. This is not an emergency service: if there is a fire now, call 112.

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 8 September 2025 to 21 September 2025. 82 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 2025, 100 m cells), summed inside the perimeter: an estimate of what was there, not a damage count.

How we build fire pages: methodology ›

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.

Where it burned