Burned area
satellite only660ha
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.
HR · Croatia · –
Općina Gračac fire, 1 April 2020 Općina Udbina, Općina Gračac, Općina Lovinac
Out · last detection 6 Apr 2020, 12:06 UTC
The fire started on 1 April 2020 in Općina Gračac, Croatia, and satellites saw it burning for 8 days. Copernicus mapped a burnt perimeter of 660 hectares from satellite imagery, spread across 3 municipalities.
It is the 14th largest in Zadar County since 2016 (of 55 with a page). Number 7 in Croatia in 2020, of 32.
The power measured by the satellite is low (7.7 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 only8days
1 Apr 2020 to 8 Apr 2020: first and last day with fire on the page.
- Source
- EFFIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- last detection: 6 Apr 2020, 12:06 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 only1 Apr 2020
First day with fire seen by the satellites or the perimeter.
- Source
- EFFIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- 1 Apr 2020
+− cross-check
No official record is matched to this page, so the alert time and the cause are not known here.
Hotspots
satellite only14
VIIRS detections at 375 m. Most intense hotspot: 8 MW.
- Source
- NASA FIRMS · VIIRS (Suomi NPP)
- Date
- 1 Apr 2020 – 8 Apr 2020
+− 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 only24MW
Total radiative power on 2 April 2020; hotspots that day: 5.
- Source
- NASA FIRMS · VIIRS (FRP)
- Date
- 2 Apr 2020
+− 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
model4.0FWI · very low
Fire Weather Index (Canadian system) computed by WorldFires for the day the fire started. Consecutive days without rain before: 5.
- Source
- WorldFires calculation (Canadian FWI system)
- Date
- 1 Apr 2020, 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
model17.7°C · 20% RH
High of 17.7 °C and minimum humidity of 20% on 8 April 2020; gusts of 77 km/h on 1 April 2020.
- Source
- weather model at the fire’s grid cell
- Date
- 1 Apr 2020 – 8 Apr 2020
- 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 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
- 660 ha
- Dates
- 1 Apr 2020 – 8 Apr 2020
- Name
- Općina Gračac
- Official record
- —
Versioned permanent link
https://worldfires.org/en/fire/opcina-gracac-2020-04?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 opcina-gracac-2020-04.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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2020-04-01 | 2 | 5 | 5.6 | -2.7 | 26 | 25 | 76.7 | 0 | 4 | muy_bajo | 1 |
| 2020-04-02 | 5 | 24 | 11.8 | -2.8 | 29 | 8.7 | 23.8 | 0 | 3.2 | muy_bajo | 1 |
| 2020-04-03 | 0 | 0 | 14 | -1.3 | 19 | 9.8 | 36 | 0 | 5.6 | bajo | 1 |
| 2020-04-04 | 0 | 0 | 13.2 | 2.6 | 30 | 24.1 | 74.9 | 0 | 9.7 | bajo | 1 |
| 2020-04-05 | 4 | 8 | 15 | 3.8 | 33 | 24.7 | 72.4 | 0 | 10.7 | bajo | 1 |
| 2020-04-06 | 3 | 15 | 17.3 | 3.3 | 27 | 15.1 | 41.4 | 0 | 8.7 | bajo | 1 |
| 2020-04-07 | 0 | 0 | 16.7 | 1 | 24 | 14.5 | 42.5 | 0 | 9.6 | bajo | 1 |
| 2020-04-08 | 0 | 0 | 17.7 | 0.4 | 20 | 13.8 | 37.1 | 0 | 11.1 | bajo | 1 |
| 2020-04-09 | 0 | 0 | 20.3 | 0.8 | 19 | 8.2 | 23.8 | 0 | 10.9 | bajo | 0 |
| 2020-04-10 | 0 | 0 | 20.4 | 3.4 | 22 | 12.3 | 39.2 | 0 | 13.2 | moderado | 0 |
| 2020-04-11 | 0 | 0 | 20.8 | 5.3 | 28 | 7 | 23.4 | 0 | 11.9 | moderado | 0 |
| 2020-04-12 | 0 | 0 | 20.2 | 5.8 | 30 | 11.7 | 36.4 | 0 | 13.8 | moderado | 0 |
| 2020-04-13 | 0 | 0 | 17.7 | 7 | 38 | 16.2 | 49 | 0 | 13.8 | moderado | 0 |
| 2020-04-14 | 0 | 0 | 11.1 | 0.4 | 62 | 22.4 | 66.6 | 15.4 | 0.1 | muy_bajo | 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). Open-Meteo.com · How we build fire pages: methodology
- Burnt area
- 660ha
- Copernicus perimeter
- Duration
- 8days
- 1 Apr 2020 – 8 Apr 2020
- Municipalities hit
- 3
- municipalities
- Started on
- 1 Apr
- 2020
- Heat detections
- 14
- in a single hotspot: 8 MW
- Danger at start
- 4
- Very low · FWI index
- Average daily power
- 13MW
- detected power per day, on average
Where it burned
HOTSPOTS BY DAY
1 Apr8 Apr
6 Apr 2020
How it evolved, day by day
1 Apr
2 Apr
5 Apr
6 Apr
Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.
The weather it burned in
18°high
77km/h · peak gust
19%lowest humidity
It had gone 5 days without rain (1 mm or more) when it started. Rain came after the fire: 15.4 mm on 14 Apr.
This area had burned before
48% of the perimeter overlaps earlier fires recorded since 2016: 314 ha in 2019.
How big is it?
London boundary: geoBoundaries · Office for National Statistics (Open Government Licence v3.0).
Zagreb boundary: geoBoundaries · OpenStreetMap, Wambacher · © OpenStreetMap contributors (ODbL 1.0).
Paris boundary: geoBoundaries · Institut national de l'information géographique et forestière (IGN-F) (Etalab Open License 2.0).
Madrid boundary: geoBoundaries · Open Data ESRI, IGN Central Registry of Cartography Area (CC BY 4.0).
This compares size, not location: both shapes are at the same scale, north up, centred on each other.
What happened to each town
-
341 ha reached on 2 Apr0.5 %
-
Općina Gračac where it started312 ha reached on 1 Apr0.3 %
-
7 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
- Broadleaved forest59 %
- Scrub and transitional woodland40 %
- Other natural land0.8 %
Land cover inside the perimeter according to Corine Land Cover, as reported by Copernicus.
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 Strong wind: 26 % of the area in Croatia
| Day | High | Min. humidity | Peak gust | Rain | Danger (FWI) |
|---|---|---|---|---|---|
| 1 Apr | 5.6 °C | 26 % | 77 km/h | 0.0 mm | Very low 4 |
| 2 Apr | 11.8 °C | 29 % | 24 km/h | 0.0 mm | Very low 3 |
| 3 Apr | 14.0 °C | 19 % | 36 km/h | 0.0 mm | Low 6 |
| 4 Apr | 13.2 °C | 30 % | 75 km/h | 0.0 mm | Low 10 |
| 5 Apr | 15.0 °C | 33 % | 72 km/h | 0.0 mm | Low 11 |
| 6 Apr | 17.3 °C | 27 % | 41 km/h | 0.0 mm | Low 9 |
| 7 Apr | 16.7 °C | 24 % | 42 km/h | 0.0 mm | Low 10 |
| 8 Apr | 17.7 °C | 20 % | 37 km/h | 0.0 mm | Low 11 |
| 9 Apr after | 20.3 °C | 19 % | 24 km/h | 0.0 mm | Low 11 |
| 10 Apr after | 20.4 °C | 22 % | 39 km/h | 0.0 mm | Moderate 13 |
| 11 Apr after | 20.8 °C | 28 % | 23 km/h | 0.0 mm | Moderate 12 |
| 12 Apr after | 20.2 °C | 30 % | 36 km/h | 0.0 mm | Moderate 14 |
| 13 Apr after | 17.7 °C | 38 % | 49 km/h | 0.0 mm | Moderate 14 |
| 14 Apr after | 11.1 °C | 62 % | 67 km/h | 15.4 mm | Very low 0 |
Its twins: fires that started in the same weather
It started with an FWI of 4.0, a minimum humidity of 26% and 5 days without rain. Fires in the area that started in weather like this since 2016: 30.
FWI at the start
4.0
Minimum humidity
26 %
Days without rain
5
this fire
chosen twins
rest of the area
Almost identicalSimilar
Outlines of the closest twins
This fire · Općina Gračac fire, 1 April 2020
660 ha
8 days
FWI 4.0
Min. humidity 26 %
Općina Gračac fire, March 2017
1,680 ha
5 days
FWI 3.7
Min. humidity 25 %
15 km away, in 2017
First rain (1 mm or more) after it ended: 3.0 mm on 26 Mar.
Bihać fire, March 2025
693 ha
4 days
FWI 4.5
Min. humidity 25 %
38 km away, in 2025
First rain (1 mm or more) after it ended: 27.2 mm on 11 Mar.
Bosanski Petrovac fire, March 2025
174 ha
1 day
FWI 5.7
Min. humidity 26 %
43 km away, in 2025
First rain (1 mm or more) after it ended: 1.4 mm on 10 Mar.
Općina Gračac fire, March 2019
317 ha
3 days
FWI 5.2
Min. humidity 25 %
22 km away, in 2019
First rain (1 mm or more) after it ended: 1.7 mm on 4 Apr.
Bosansko Grahovo fire, March 2016
1,078 ha
2 days
FWI 2.7
Min. humidity 26 %
46 km away, in 2016
First rain (1 mm or more) after it ended: 3.1 mm on 21 Mar.
What happened to them
- 2 days
- median duration
- 234 ha
- median area
- 13 %
- went past 1,000 ha
- 3.8 mm
- rain at the end (median; 29 of 30 had it)
It was 2.8 times larger than the median of its twins and lasted 8 days, against 2 days.
Only 6 of its 30 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 1 of 30, 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 3.8 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
15.4 mmfirst rain
14 Apr6 days after it ended
77km/h · max. gust
It was considered over on 8 Apr, and on 14 Apr 15.4 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 29 of 30, with a median of 3.8 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 · 25 Mar 2020
After · 15 Apr 2020
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.
The smoke
CAMS · CopernicusOn 30 March 2020 the air beside the fire reached 26 µg/m³ of PM2.5. That day averaged 17: 1.2 times the WHO daily guideline (15).
PM2.5 peak26 µg/m³
Days over the guideline4 days
PM1035 µg/m³
WHO 15
30 Mar2 Apr5 Apr8 Apr
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 · 14Every 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
- 3,936 haOpćina Gračac22 March 2022 · 8 days · 2 km away
- 2,218 haOpćina UdbinaApril 2020 · 7 days · 23 km away
- 1,823 haOpćina Jasenice13 August 2017 · 10 days · 24 km away
- 4,959 haOpćina Gračac5 April 2020 · 9 days · 28 km away
- 3,528 haBihać20 March 2022 · 10 days · 34 km away
- 4,086 haOpćina Gračac5 August 2017 · 7 days · 35 km away
Frequently asked questions
- How long did the Općina Gračac fire last?
- According to the heat detections seen by satellite inside the perimeter, it burned from 1 April 2020 to 8 April 2020 (8 days). The perimeter dates it from 1 April 2020 to 4 April 2020.
- How much area did it burn?
- The perimeter Copernicus measured from satellite imagery is 660 hectares (6.6 km²). Official national figures may differ.
- Which municipalities burned?
- The fire entered 3 municipalities: Općina Udbina (341 ha, 0.5 %); Općina Gračac (312 ha, 0.3 %); Općina Lovinac (7 ha, 0.0 %).
- What was the weather like?
- During the fire the temperature reached 17.7 °C, humidity dropped to 19 % and gusts hit 77 km/h. The fire danger index (FWI) reached 11, class Low.
- Where does this data come from?
- From the EFFIS (Copernicus) burnt perimeter, NASA FIRMS VIIRS hotspots and the administrative boundaries of Croatia (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: 30. Their median duration was 2 days and their median area 234 ha; 13 % went past 1,000 ha. Only 6 of its 30 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 1 of 30, 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 3.8 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 · 193 · 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 adjusted with the VIIRS detections inside the perimeter, which said 1 April 2020 to 4 April 2020. 14 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.
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 (Creative Commons Attribution-ShareAlike 2.0). 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.