Burned area
satellite only110ha
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, 21 March 2017 Općina Gračac
Out · last detection 21 Mar 2017, 11:16 UTC
The fire started on 21 March 2017 in Općina Gračac, Croatia, and satellites saw it burning for 1 day. Copernicus mapped a burnt perimeter of 110 hectares from satellite imagery, spread across a single municipality.
It is the 50th largest in Zadar County since 2016 (of 55 with a page). Number 75 in Croatia in 2017, of 78.
The power measured by the satellite is low (13.9 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 only1day
21 Mar 2017 to 21 Mar 2017: first and last day with fire on the page.
- Source
- EFFIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- last detection: 21 Mar 2017, 11:16 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 only21 Mar 2017
First day with fire seen by the satellites or the perimeter.
- Source
- EFFIS (Copernicus) · NASA FIRMS · VIIRS
- Date
- 21 Mar 2017
+− cross-check
No official record is matched to this page, so the alert time and the cause are not known here.
Hotspots
satellite only4
VIIRS detections at 375 m. Most intense hotspot: 14 MW.
- Source
- NASA FIRMS · VIIRS (Suomi NPP)
- Date
- 21 Mar 2017 – 21 Mar 2017
+− 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 only44MW
Total radiative power on 21 March 2017; hotspots that day: 4.
- Source
- NASA FIRMS · VIIRS (FRP)
- Date
- 21 Mar 2017
+− 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
model7.1FWI · low
Fire Weather Index (Canadian system) computed by WorldFires for the day the fire started. Consecutive days without rain before: 9.
- Source
- WorldFires calculation (Canadian FWI system)
- Date
- 21 Mar 2017, 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
model19.5°C · 38% RH
High of 19.5 °C and minimum humidity of 38% on 21 March 2017; gusts of 35 km/h on 21 March 2017.
- Source
- weather model at the fire’s grid cell
- Date
- 21 Mar 2017 – 21 Mar 2017
- 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
- 110 ha
- Dates
- 21 Mar 2017 – 21 Mar 2017
- Name
- Općina Gračac
- Official record
- —
Versioned permanent link
https://worldfires.org/en/fire/opcina-gracac-2017-03-6?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-2017-03-6.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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 2017-03-21 | 4 | 44 | 19.5 | 5.3 | 38 | 10.8 | 34.9 | 0 | 7.1 | bajo | 1 |
| 2017-03-22 | 0 | 0 | 17.1 | 6 | 49 | 15.6 | 48.6 | 0 | 8.9 | bajo | 0 |
| 2017-03-23 | 0 | 0 | 18.5 | 6.6 | 42 | 12.9 | 44.3 | 0 | 8.7 | bajo | 0 |
| 2017-03-24 | 0 | 0 | 20.8 | 5.9 | 27 | 8.4 | 21.2 | 0 | 6.4 | bajo | 0 |
| 2017-03-25 | 0 | 0 | 16 | 5.5 | 49 | 9.2 | 29.9 | 0 | 7 | bajo | 0 |
| 2017-03-26 | 0 | 0 | 8.1 | 1.3 | 64 | 16.1 | 46.1 | 3 | 7.7 | 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), GHSL (JRC). Open-Meteo.com · How we build fire pages: methodology
- Burnt area
- 110ha
- Copernicus perimeter
- Duration
- 1day
- 21 Mar 2017 – 21 Mar 2017
- Municipalities hit
- 1
- municipalities
- Started on
- 21 Mar
- 2017
- Heat detections
- 4
- in a single hotspot: 14 MW
- Danger at start
- 7
- Low · FWI index
- Average daily power
- 44MW
- detected power per day, on average
Where it burned
HOTSPOTS BY DAY
21 Mar21 Mar
How it evolved, day by day
21 Mar 2017 · 44 MW · 4
Fire radiative power detected each day, in megawatts, and number of hotspots. The magenta bar marks the peak day.
The weather it burned in
20°high
35km/h · peak gust
38%lowest humidity
It had gone 9 days without rain (1 mm or more) when it started. Rain came after the fire: 3.0 mm on 26 Mar.
This area had burned before
No earlier perimeters overlap this fire since 2016, when the satellite record begins.
What happened to each town
-
Općina Gračac where it started111 ha reached on 21 Mar0.1 %
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 land71 %
- Scrub and transitional woodland29 %
Land cover inside the perimeter according to Corine Land Cover, as reported by Copernicus.
People and buildings inside the perimeter
GHSL 2015Built-up area< 0.1 ha
Residents< 20
Inside the perimeter there was no noticeable built-up land and almost nobody lived there (GHSL 2015, 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)
| Day | High | Min. humidity | Peak gust | Rain | Danger (FWI) |
|---|---|---|---|---|---|
| 21 Mar | 19.5 °C | 38 % | 35 km/h | 0.0 mm | Low 7 |
| 22 Mar after | 17.1 °C | 49 % | 49 km/h | 0.0 mm | Low 9 |
| 23 Mar after | 18.5 °C | 42 % | 44 km/h | 0.0 mm | Low 9 |
| 24 Mar after | 20.8 °C | 27 % | 21 km/h | 0.0 mm | Low 6 |
| 25 Mar after | 16.0 °C | 49 % | 30 km/h | 0.0 mm | Low 7 |
| 26 Mar after | 8.1 °C | 64 % | 46 km/h | 3.0 mm | Low 8 |
Its twins: fires that started in the same weather
It started with an FWI of 7.1, a minimum humidity of 38% and 9 days without rain. Fires in the area that started in weather like this since 2016: 28.
FWI at the start
7.1
Minimum humidity
38 %
Days without rain
9
this fire
chosen twins
rest of the area
Almost identicalSimilar
Outlines of the closest twins
This fire · Općina Gračac fire, 21 March 2017
110 ha
1 day
FWI 7.1
Min. humidity 38 %
Grad Gospić fire, April 2016
360 ha
2 days
FWI 8.1
Min. humidity 39 %
51 km away, in 2016
First rain (1 mm or more) after it ended: 1.3 mm on 8 Apr.
Grad Gospić fire, March 2022
415 ha
1 day
FWI 6.0
Min. humidity 37 %
36 km away, in 2022
First rain (1 mm or more) after it ended: none in the following ten days.
Općina Donji Lapac fire, March 2020
145 ha
3 days
FWI 8.1
Min. humidity 36 %
18 km away, in 2020
First rain (1 mm or more) after it ended: 2.5 mm on 22 Mar.
Općina Donji Lapac fire, March 2020
1,066 ha
4 days
FWI 8.3
Min. humidity 36 %
17 km away, in 2020
First rain (1 mm or more) after it ended: 2.5 mm on 22 Mar.
Općina Gračac fire, February 2019
114 ha
1 day
FWI 6.8
Min. humidity 40 %
20 km away, in 2019
First rain (1 mm or more) after it ended: 1.5 mm on 1 Mar.
What happened to them
- 2 days
- median duration
- 177 ha
- median area
- 14 %
- went past 1,000 ha
- 2.5 mm
- rain at the end (median; 22 of 28 had it)
It stayed below its twins: 110 ha against a median of 177 ha. It lasted 1 day, against 2 days.
In 6 of 28, 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
3.0 mmfirst rain
26 Mar5 days after it ended
35km/h · max. gust
It was considered over on 21 Mar, and on 26 Mar 3.0 mm fell. We do not know whether the rain or the firefighters put it out. Twins with rain when they ended: 22 of 28, 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 · 14 Mar 2017
After · 28 Mar 2017
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 19 March 2017 the air beside the fire reached 21 µg/m³ of PM2.5. That day averaged 17: 1.1 times the WHO daily guideline (15).
PM2.5 peak21 µg/m³
Days over the guideline1 day
PM1025 µg/m³
WHO 15
19 Mar21 Mar23 Mar
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 · 4Every 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 · 7 km away
- 4,959 haOpćina Gračac5 April 2020 · 9 days · 23 km away
- 3,528 haBihać20 March 2022 · 10 days · 25 km away
- 4,086 haOpćina Gračac5 August 2017 · 7 days · 27 km away
- 4,225 haOpćina Gračac21 March 2022 · 7 days · 30 km away
- 3,515 haBosansko Grahovo22 March 2022 · 8 days · 31 km away
Frequently asked questions
- How long did the Općina Gračac fire last?
- Copernicus dates it between 21 March 2017 and 21 March 2017: 1 day between the first and last image with fire.
- How much area did it burn?
- The perimeter Copernicus measured from satellite imagery is 110 hectares (1.1 km²). Official national figures may differ.
- Which municipalities burned?
- The fire only entered Općina Gračac (111 ha, 0.1 %).
- What was the weather like?
- During the fire the temperature reached 19.5 °C, humidity dropped to 38 % and gusts hit 35 km/h. The fire danger index (FWI) reached 7, 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: 28. Their median duration was 2 days and their median area 177 ha; 14 % went past 1,000 ha. In 6 of 28, 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 · 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 from the perimeter: the VIIRS detections inside it did not change them. 4 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 2015, 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 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.