How long did the Calai fire last?

According to the heat detections seen by satellite inside the perimeter, it burned from 31 August 2026 to 17 September 2026 (18 days). The perimeter dates it from 31 August 2026 to 15 September 2026.

How much area did it burn?

The perimeter GWIS (Copernicus) rebuilt from heat detections is 9,539 hectares (95.4 km²). It is an estimate: official national figures may differ.

Which municipalities burned?

The fire entered 2 municipalities: Calai (8,755 ha, 1.1 %); Cuangar (818 ha, 0.0 %).

What was the weather like?

During the fire the temperature reached 36.5 °C, humidity dropped to 8 % and gusts hit 55 km/h. The fire danger index (FWI) reached 63, class Extreme.

Where does this data come from?

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

AO · Angola · 2026-08-31 → 2026-09-17

Calai fire, 31 August 2026 Calai, Cuangar

Out · last detection 17 Sept 2026, 12:46 UTC

The fire started on 31 August 2026 in Calai, Angola, and satellites saw it burning for 18 days. Copernicus’s global GWIS system rebuilt a burnt perimeter of 9,539 hectares from heat detections, spread across 2 municipalities.

It is the 210th largest in Cuando Cubango since 2016 (of 660 with a page). Number 174 in Angola in 2026, of 487.

Compare with…

Suggestions: Calai · 2019 Cuangar · 2023 Nancova · 2026 Nancova · 2025

Burnt area: 9,539ha; GWIS perimeter (Copernicus)
Duration: 18days; 31 Aug 2026 – 17 Sept 2026
Municipalities hit: 2; municipalities
Started on: 31 Aug; 2026
Heat detections: 222; in a single hotspot: 33 MW
Danger at start: 54; Extreme · FWI index
Average daily power: 104MW; detected power per day, on average

HOTSPOTS BY DAY 31 Aug17 Sept

Play back 17 Sept 2026

How it evolved, day by day

31 Aug 3 Sept 4 Sept 6 Sept 9 Sept 12 Sept 17 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

36°high

55km/h · peak gust

8%lowest humidity

It had gone more than two months without rain (1 mm or more) when it started.

This area had burned before

84% of the perimeter overlaps earlier fires recorded since 2016: 167 ha in 2016, 386 ha in 2017, 3,263 ha in 2018, 3,867 ha in 2019, 3,449 ha in 2020, 2,751 ha in 2021, 2,311 ha in 2022, 1,293 ha in 2023, 888 ha in 2024. Part of it burned more than once, so the yearly figures add up to more than the 7,981 ha that had burned before.

How big is it?

It burned the equivalent of 6% of the area of London (95 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

Calai where it started

8,755 ha reached on 31 Aug

1.1 %
Cuangar

818 ha reached on 1 Sept

0.0 %

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)
31 Aug	34.0 °C	14 %	35 km/h	0.0 mm	Extreme 54
1 Sept	34.5 °C	12 %	42 km/h	0.0 mm	Extreme 60
2 Sept	33.8 °C	13 %	32 km/h	0.0 mm	Extreme 52
3 Sept	34.9 °C	13 %	35 km/h	0.0 mm	Extreme 56
4 Sept	33.4 °C	8 %	37 km/h	0.0 mm	Extreme 57
5 Sept	31.4 °C	9 %	27 km/h	0.0 mm	Extreme 51
6 Sept	33.0 °C	13 %	19 km/h	0.0 mm	Very high 50
7 Sept	34.3 °C	17 %	32 km/h	0.0 mm	Extreme 53
8 Sept	33.5 °C	21 %	51 km/h	0.0 mm	Extreme 59
9 Sept	31.3 °C	22 %	55 km/h	0.0 mm	Extreme 63
10 Sept	30.8 °C	21 %	46 km/h	0.0 mm	Extreme 54
11 Sept	32.0 °C	15 %	42 km/h	0.0 mm	Extreme 52
12 Sept	34.1 °C	12 %	41 km/h	0.0 mm	Extreme 56
13 Sept	35.6 °C	15 %	42 km/h	0.0 mm	Extreme 57
14 Sept	33.7 °C	22 %	41 km/h	0.0 mm	Extreme 54
15 Sept	35.6 °C	15 %	27 km/h	0.2 mm	Very high 48
16 Sept	36.5 °C	16 %	34 km/h	0.0 mm	Extreme 52
17 Sept	36.3 °C	11 %	40 km/h	0.0 mm	Extreme 58
18 Sept after	34.7 °C	16 %	50 km/h	0.0 mm	Extreme 65
19 Sept after	30.9 °C	24 %	31 km/h	0.5 mm	Very high 49
20 Sept after	31.2 °C	21 %	31 km/h	0.1 mm	Very high 47
21 Sept after	29.8 °C	36 %	32 km/h	0.0 mm	High 37
22 Sept after	32.4 °C	21 %	34 km/h	0.0 mm	Very high 40
23 Sept after	33.3 °C	21 %	44 km/h	0.0 mm	Very high 48
24 Sept after	35.3 °C	16 %	50 km/h	0.0 mm	Extreme 59
25 Sept after	35.8 °C	11 %	48 km/h	0.0 mm	Extreme 64
26 Sept after	36.6 °C	11 %	44 km/h	0.0 mm	Extreme 61
27 Sept after	36.8 °C	12 %	42 km/h	0.0 mm	Extreme 59

Before and after, from space

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

↔

Before · 24 Aug 2026

After · 24 Sept 2026

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 29 August 2026 the air beside the fire reached 86 µg/m³ of PM2.5. That day averaged 48: 3.2 times the WHO daily guideline (15).

PM2.5 peak86 µg/m³

Days over the guideline18 days

PM1088 µg/m³

Optical depth1.04

WHO 15

2930311234567891011121314151617181920

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 · 222Every 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 Angola ›

Frequently asked questions

How long did the Calai fire last?: According to the heat detections seen by satellite inside the perimeter, it burned from 31 August 2026 to 17 September 2026 (18 days). The perimeter dates it from 31 August 2026 to 15 September 2026.
How much area did it burn?: The perimeter GWIS (Copernicus) rebuilt from heat detections is 9,539 hectares (95.4 km²). It is an estimate: official national figures may differ.
Which municipalities burned?: The fire entered 2 municipalities: Calai (8,755 ha, 1.1 %); Cuangar (818 ha, 0.0 %).
What was the weather like?: During the fire the temperature reached 36.5 °C, humidity dropped to 8 % and gusts hit 55 km/h. The fire danger index (FWI) reached 63, class Extreme.
Where does this data come from?: From the GWIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Angola (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

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.

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 31 August 2026 to 15 September 2026. 222 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 (Public Domain). 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