Burned area
satellite only367ha
Perimeter published by EFFIS (Copernicus).
- Source
- EFFIS (Copernicus)
- Date
- perimeter revised on 26 January 2022
+− cross-check
No official record is matched to this page to compare it with.
IT · Italy · –
Irsina fire, August 2021 Gravina in Puglia, Irsina, Matera
Out · last detection 3 Aug 2021, 01:08 UTC
The fire started on 2 August 2021 in Irsina, Italy, and satellites saw it burning for 3 days. Copernicus mapped a burnt perimeter of 367 hectares from satellite imagery, spread across 4 municipalities.
It is the 4th largest in Matera since 2016 (of 30 with a page). Number 74 in Italy in 2021, of 291.
The power measured by the satellite is low (19.8 MW in the strongest hotspot), more typical of grass or stubble burning, or a slow surface fire, than of a large crown fire.
Use this data
Compare with…
Use this data
Fire page data · version 2026-10-24matches the official recordwith caveatssatellite onlymodel
When copying, the sentence is
Tick the figures you want: they make up the lede and the CSV.
Duration by satellite
satellite only3days
2 Aug 2021 to 4 Aug 2021: first and last day with fire on the page.
- Source
- EFFIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- last detection: 3 Aug 2021, 01:08 UTC
+− cross-check
Satellites pass a few times a day and cloud or smoke can hide the fire: a lack of detections is not an official extinction. Each country’s emergency service declares a fire contained or out.
Start
satellite only2 Aug 2021
First day with fire seen by the satellites or the perimeter.
- Source
- EFFIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- 2 Aug 2021
+− cross-check
No official record is matched to this page, so the alert time and the cause are not known here.
Hotspots
satellite only8
VIIRS detections at 375 m. Most intense hotspot: 20 MW.
- Source
- NASA FIRMS · VIIRS (Suomi NPP)
- Date
- 2 Aug 2021 – 4 Aug 2021
+− cross-check
There is no official record to compare with. Each hotspot is a pixel detected in one satellite pass, not a separate fire.
The worst day
satellite only113MW
Total radiative power on 2 August 2021; hotspots that day: 7.
- Source
- NASA FIRMS · VIIRS (FRP)
- Date
- 2 Aug 2021
+− cross-check
Fire radiative power (FRP) measures the energy the fire gives off when the satellite passes. Added up by day, it compares intensity, not area.
Danger at the start
model50.9FWI · extreme
Fire Weather Index (Canadian system) computed by WorldFires for the day the fire started. Consecutive days without rain before: 13.
- Source
- WorldFires calculation (Canadian FWI system)
- Date
- 2 Aug 2021, local noon
- Model
- ERA5 0,25° (ECMWF · Copernicus C3S) · Open-Meteo.com
+− cross-check
This is an index computed from weather model data, not a measurement of the fire nor an official warning. Danger warnings are issued by each country’s authority. Emergency number and official warnings
Weather during the fire
model36.5°C · 25% RH
High of 36.5 °C and minimum humidity of 25% on 2 August 2021; gusts of 50 km/h on 3 August 2021.
- Source
- weather model at the fire’s grid cell
- Date
- 2 Aug 2021 – 4 Aug 2021
- Model
- ERA5 0,25° (ECMWF · Copernicus C3S) · Open-Meteo.com
+− cross-check
These are model values for a cell of about 25 km, not from a weather station: they may differ from what was measured on the ground.
This page’s change log has been kept since 24 October 2026: every night what it publishes is compared and the difference is logged. Anything earlier is reconstructed from each source’s date and marked as reconstructed.
Show
-
· reconstructed weatherWeather and FWI computed from the ERA5 reanalysis
-
· reconstructed GHSLPopulation and built-up area computed
-
· reconstructed perimeterEFFIS (Copernicus) revises the perimeter
What was saved on 24 October 2026
Every night a snapshot of what the page shows is saved. If anything changes, it appears in the list as a log entry.
- Area
- 367 ha
- Dates
- 2 Aug 2021 – 4 Aug 2021
- Name
- Irsina
- Official record
- —
Versioned permanent link
https://worldfires.org/en/fire/irsina-2021-08?v=2026-10-24A version keeps the area, dates, name and official record; the area as it was logged (changes under 2% are not logged). The map, hotspots and weather always show today’s data.
Citation
A lede of about 60 words figures only, no adjectives
CSV for this fire irsina-2021-08.csv · daily, no individual hotspots
| fecha | focos_viirs | frp_mw | tmax_c | tmin_c | hr_min_pct | viento_max_kmh | racha_max_kmh | precip_mm | fwi | clase_fwi | dentro_del_incendio |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2021-08-02 | 7 | 113 | 36.5 | 24.4 | 25 | 12.6 | 39.6 | 0 | 50.9 | extremo | 1 |
| 2021-08-03 | 1 | 1 | 33.8 | 21.3 | 26 | 24.9 | 50.4 | 0 | 62.1 | extremo | 1 |
| 2021-08-04 | 0 | 0 | 34.9 | 21.8 | 29 | 15.7 | 44.6 | 0.2 | 55.5 | extremo | 1 |
| 2021-08-05 | 0 | 0 | 33.6 | 22.5 | 22 | 23 | 47.9 | 0 | 62.9 | extremo | 0 |
| 2021-08-06 | 0 | 0 | 32.3 | 21.7 | 27 | 17.7 | 37.4 | 0 | 48.9 | muy_alto | 0 |
| 2021-08-07 | 0 | 0 | 33.4 | 19.6 | 32 | 12.9 | 33.5 | 0 | 35.6 | alto | 0 |
| 2021-08-08 | 0 | 0 | 35.9 | 22.6 | 27 | 15.2 | 41.4 | 0 | 48.6 | muy_alto | 0 |
| 2021-08-09 | 0 | 0 | 38.8 | 22.7 | 21 | 5.6 | 23 | 0 | 41.4 | muy_alto | 0 |
| 2021-08-10 | 0 | 0 | 37.5 | 22.9 | 27 | 10.1 | 25.9 | 0 | 46.7 | muy_alto | 0 |
| 2021-08-11 | 0 | 0 | 34.8 | 23.5 | 34 | 15.6 | 37.1 | 0.7 | 52.3 | extremo | 0 |
| 2021-08-12 | 0 | 0 | 33.5 | 22.1 | 35 | 18.5 | 41 | 0 | 40.8 | muy_alto | 0 |
| 2021-08-13 | 0 | 0 | 35 | 21.4 | 27 | 15.5 | 34.2 | 0 | 48 | muy_alto | 0 |
| 2021-08-14 | 0 | 0 | 34.3 | 21 | 30 | 15.9 | 35.3 | 0 | 48.8 | muy_alto | 0 |
It is generated in your browser from this page’s data: one file per fire, aggregated by day and without individual hotspots.
Live widget for your story
It updates itself while the fire is still active and links to this page. Free, with the attribution shown at the bottom.
Sources for this page: EFFIS (Copernicus), NASA FIRMS (VIIRS), ERA5 (ECMWF/Copernicus C3S) · Open-Meteo.com (CC BY 4.0), GHSL (JRC). Open-Meteo.com · How we build fire pages: methodology
- Burnt area
- 367ha
- Copernicus perimeter
- Duration
- 3days
- 2 Aug 2021 – 4 Aug 2021
- Municipalities hit
- 4
- municipalities
- Started on
- 2 Aug
- 2021
- Heat detections
- 8
- in a single hotspot: 20 MW
- Danger at start
- 51
- Extreme · FWI index
- Average daily power
- 57MW
- detected power per day, on average
Where it burned
HOTSPOTS BY DAY
2 Aug4 Aug
3 Aug 2021
How it evolved, day by day
2 Aug
3 Aug
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
50km/h · peak gust
25%lowest humidity
It had gone 13 days without rain (1 mm or more) when it started.
This area had burned before
No earlier perimeters overlap this fire since 2016, when the satellite record begins.
What happened to each town
-
Gravina in Puglia 42,703 inhabitants · 10.2 km from the centre258 ha reached on 2 Aug0.7 %
-
101 ha reached on 2 Aug0.4 %
-
Matera 59,685 inhabitants · 17.1 km from the centre7 ha0.0 %
-
Grottole 2,031 inhabitants · 10.5 km from the centre0 ha0.0 %
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
- Agricultural areas62 %
- Sclerophyllous scrub18 %
- Mixed forest12 %
- Broadleaved forest6.0 %
- Coniferous forest1.4 %
- Scrub and transitional woodland0.5 %
Natura 2000 protected area affected: 67 %
- LIC Bosco Difesa Grande IT9120008
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 2020Built-up area< 0.1 ha
Residents< 20
Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2020, 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.
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: 23 % of the area in Italy
| Day | High | Min. humidity | Peak gust | Rain | Danger (FWI) |
|---|---|---|---|---|---|
| 2 Aug | 36.5 °C | 25 % | 40 km/h | 0.0 mm | Extreme 51 |
| 3 Aug | 33.8 °C | 26 % | 50 km/h | 0.0 mm | Extreme 62 |
| 4 Aug | 34.9 °C | 29 % | 45 km/h | 0.2 mm | Extreme 56 |
| 5 Aug after | 33.6 °C | 22 % | 48 km/h | 0.0 mm | Extreme 63 |
| 6 Aug after | 32.3 °C | 27 % | 37 km/h | 0.0 mm | Very high 49 |
| 7 Aug after | 33.4 °C | 32 % | 34 km/h | 0.0 mm | High 36 |
| 8 Aug after | 35.9 °C | 27 % | 41 km/h | 0.0 mm | Very high 49 |
| 9 Aug after | 38.8 °C | 21 % | 23 km/h | 0.0 mm | Very high 41 |
| 10 Aug after | 37.5 °C | 27 % | 26 km/h | 0.0 mm | Very high 47 |
| 11 Aug after | 34.8 °C | 34 % | 37 km/h | 0.7 mm | Extreme 52 |
| 12 Aug after | 33.5 °C | 35 % | 41 km/h | 0.0 mm | Very high 41 |
| 13 Aug after | 35.0 °C | 27 % | 34 km/h | 0.0 mm | Very high 48 |
| 14 Aug after | 34.3 °C | 30 % | 35 km/h | 0.0 mm | Very high 49 |
Its twins: fires that started in the same weather
It started with an FWI of 50.9, a minimum humidity of 25% and 13 days without rain. Fires in the area that started in weather like this since 2016: 38.
FWI at the start
50.9
Minimum humidity
25 %
Days without rain
13
this fire
chosen twins
rest of the area
Almost identicalSimilar
Outlines of the closest twins
This fire · Irsina fire, August 2021
367 ha
3 days
FWI 50.9
Min. humidity 25 %
Ginestra fire, August 2026
142 ha
1 day
FWI 51.2
Min. humidity 27 %
63 km away, in 2026
First rain (1 mm or more) after it ended: 1.1 mm on 13 Aug.
Gravina in Puglia fire, August 2026
238 ha
4 days
FWI 47.9
Min. humidity 26 %
22 km away, in 2026
First rain (1 mm or more) after it ended: 1.6 mm on 12 Aug.
Minervino Murge fire, August 2026
601 ha
1 day
FWI 47.4
Min. humidity 26 %
52 km away, in 2026
First rain (1 mm or more) after it ended: 1.0 mm on 12 Aug.
Minervino Murge fire, July 2024
168 ha
1 day
FWI 49.5
Min. humidity 27 %
47 km away, in 2024
First rain (1 mm or more) after it ended: 2.8 mm on 22 Jul.
Manfredonia fire, July 2025
804 ha
5 days
FWI 51.3
Min. humidity 23 %
104 km away, in 2025
First rain (1 mm or more) after it ended: 1.4 mm on 26 Jul.
What happened to them
- 2 days
- median duration
- 204 ha
- median area
- 3 %
- went past 1,000 ha
- 2.5 mm
- rain at the end (median; 33 of 38 had it)
It was 1.8 times larger than the median of its twins and lasted 3 days, against 2 days.
Only 10 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 5 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 2.5 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
—first rain
—no rain in ten days
50km/h · max. gust
It was considered over on 4 Aug, and not even 1 mm fell in the following ten days: it went out without rain. Twins with rain when they ended: 33 of 38, with a median of 2.5 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.
Before and after, from space
Drag the line to compare the same ground before the fire and after it.
↔
Before · 26 Jul 2021
After · 11 Aug 2021
Sentinel-2 did not pass over on that day. Try another date, or use false colour, which is daily.
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 · 8Every 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
- 1,309 haGravina in PugliaAugust 2017 · 5 days · 4 km away
- 1,059 haGravina in PugliaJuly 2021 · 5 days · 8 km away
- 571 haIrsinaJuly 2025 · 1 day · 18 km away
- 3,455 haGravina in Puglia25 August 2026 · 5 days · 26 km away
- 1,300 haAltamuraJuly 2026 · 1 day · 28 km away
- 845 haCracoAugust 2026 · 2 days · 36 km away
Frequently asked questions
- How long did the Irsina fire last?
- Copernicus dates it between 2 August 2021 and 4 August 2021: 3 days between the first and last image with fire.
- How much area did it burn?
- The perimeter Copernicus measured from satellite imagery is 367 hectares (3.7 km²). Official national figures may differ.
- Which municipalities burned?
- The fire entered 4 municipalities: Gravina in Puglia (258 ha, 0.7 %); Irsina (101 ha, 0.4 %); Matera (7 ha, 0.0 %); Grottole (0 ha, 0.0 %).
- Did the fire reach a town?
- The fire came within 10.2 km of the centre of Gravina in Puglia, the closest of the areas it touched. 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 36.5 °C, humidity dropped to 25 % and gusts hit 50 km/h. The fire danger index (FWI) reached 62, class Extreme.
- Where does this data come from?
- From the EFFIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Italy (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 204 ha; 3 % went past 1,000 ha. Only 10 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 5 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 2.5 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 · 1515 · 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
How we know this
- Perimeter: EFFIS (Copernicus), mapped on satellite imagery.
- Dates from the perimeter: the VIIRS detections inside it did not change them. 8 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 2020, 100 m cells), summed inside the perimeter: an estimate of what was there, not a damage count.
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 ADM4 (Creative Commons Attribution 3.0 License). 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.