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BG · Bulgaria · –

Topolovgrad fire, September 2023 Тополовград · Svilengrad, Topolovgrad

Out · last detection 2 Sept 2023, 23:59 UTC

The fire started on 2 September 2023 in Topolovgrad, Bulgaria, and satellites saw it burning for 2 days. Copernicus mapped a burnt perimeter of 1,968 hectares from satellite imagery, spread across 2 municipalities.

It is the 4th largest in Haskovo since 2016 (of 46 with a page). Number 2 in Bulgaria in 2023, of 25.

Compare with…

Suggestions: Alexandroupolis · 2020Sredets · 2024Topolovgrad · 2020Svilengrad · 2017

Burnt area
1,968ha
Copernicus perimeter
Duration
2days
2 Sept 2023 – 3 Sept 2023
Municipalities hit
2
municipalities
Started on
2 Sept
2023
Heat detections
32
in a single hotspot: 204 MW
Danger at start
51
Extreme · FWI index
Average daily power
1.3GW
detected power per day, on average

Where it burned

HOTSPOTS BY DAY 2 Sept3 Sept

How it evolved, day by day

2 Sept 2023 · 1,262 MW · 32

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
44km/h · peak gust
31%lowest humidity

It had gone 36 days without rain (1 mm or more) when it started. Rain came after the fire: 3.5 mm on 4 Sept.

This area had burned before

73% of the perimeter overlaps earlier fires recorded since 2016: 467 ha in 2017, 1,262 ha in 2020, 358 ha in 2022. Part of it burned more than once, so the yearly figures add up to more than the 1,445 ha that had burned before.

How big is it?

10 km
It burned the equivalent of 1.2% of the area of London (20 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

  1. Svilengrad Свиленград 19,993 inhabitants · 30.0 km from the centre
    1,423 ha reached on 2 Sept
    2.0 %
  2. Topolovgrad Тополовград 8,260 inhabitants · 26.3 km from the centre where it started
    422 ha reached on 2 Sept
    0.6 %

Burnt area inside each municipality, from crossing the official 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.

What burned

  • Other natural land60 %
  • Agricultural areas27 %
  • Scrub and transitional woodland13 %

Natura 2000 protected area affected: 100 %

Natura 2000 sites (European Environment Agency, 2024 release) crossed by the perimeter.

Land cover inside the perimeter according to Corine Land Cover, as reported by Copernicus.

People and buildings inside the perimeter

GHSL 2025
Built-up area0.42 ha
Residents< 20

Inside the perimeter there were about 0.42 hectares of 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)

Started with Extreme FWI: 15 % of the area in Bulgaria

Day High Min. humidity Peak gust Rain Danger (FWI)
2 Sept 32.0 °C 33 % 42 km/h 0.1 mm Extreme 51
3 Sept 31.2 °C 31 % 44 km/h 0.0 mm Extreme 55
4 Sept after 27.7 °C 45 % 48 km/h 3.5 mm Extreme 53

Its twins: fires that started in the same weather

It started with an FWI of 51.4, a minimum humidity of 33% and 36 days without rain. Fires in the area that started in weather like this since 2016: 38.

FWI at the start 51.4
Minimum humidity 33 %
Days without rain 36
this fire chosen twins rest of the area
Almost identicalSimilar

Outlines of the closest twins

Alexandroupolis fire, September 2020
242 ha 3 days FWI 53.0 Min. humidity 31 % 108 km away, in 2020

First rain (1 mm or more) after it ended: none in the following ten days.

See its page Compare with this fire

What happened to them

2 days
median duration
387 ha
median area
16 %
went past 1,000 ha
2.0 mm
rain at the end (median; 26 of 38 had it)

It was 5.1 times larger than the median of its twins and lasted 2 days, against 2 days.

Only 4 of its 38 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 12 of 38, 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 2.0 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

3.5 mmfirst rain
4 Septthe day after it ended
44km/h · max. gust

It was considered over on 3 Sept, and on 4 Sept 3.5 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 26 of 38, with a median of 2.0 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.

How we calculate it

Before and after, from space

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

Before · 26 Aug 2023
After · 10 Sept 2023

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 31 August 2023 the air beside the fire reached 20 µg/m³ of PM2.5. That day averaged 16: 1.1 times the WHO daily guideline (15).

PM2.5 peak20 µg/m³
Days over the guideline1 day
PM1016 µg/m³
Optical depth0.51
31 Aug2 Sept4 Sept6 Sept
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 · 32Every 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 timeSatelliteFRP (MW)LatLon

Other fires nearby

All fires in Bulgaria

Frequently asked questions

How long did the Topolovgrad fire last?
Copernicus dates it between 2 September 2023 and 3 September 2023: 2 days between the first and last image with fire.
How much area did it burn?
The perimeter Copernicus measured from satellite imagery is 1,968 hectares (19.7 km²). Official national figures may differ.
Which municipalities burned?
The fire entered 2 municipalities: Svilengrad (1,423 ha, 2.0 %); Topolovgrad (422 ha, 0.6 %).
Did the fire reach a town?
The fire started in Topolovgrad and came within 26.3 km of its centre. That is the distance from the perimeter, or the nearest hotspot, to the point marking the centre; it does not mean it entered the houses.
What was the weather like?
During the fire the temperature reached 32.0 °C, humidity dropped to 31 % and gusts hit 44 km/h. The fire danger index (FWI) reached 55, class Extreme.
Where does this data come from?
From the EFFIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Bulgaria (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: 38. Their median duration was 2 days and their median area 387 ha; 16 % went past 1,000 ha. Only 4 of its 38 twins burned more. The weather on the first day does not explain everything: the wind in the following days, the fuel and the firefighting also count. In 12 of 38, 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 2.0 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.

Emergency number: 112 · Emergency number and official warnings

Satellite cross-check

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 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
What do you think is wrong?

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: EFFIS (Copernicus), mapped on satellite imagery.
  • Dates from the perimeter: the VIIRS detections inside it did not change them. 32 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 and land cover come from the Copernicus European Forest Fire Information System (EFFIS), measured on MODIS and Sentinel-2 imagery and published under CC BY 4.0. 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 slightly from each country’s official figure.