Forest and land fires

Data coverage

For each year since 2015: burned forest and land area per province and per city/regency from SiPongi, and the number of hotspots per city/regency from the S-NPP satellite. Every day: Manggala Agni firefighting reports, with date, place, area burned, and area put out. Monthly since 2015: NASA's burned area and CHIRPS rainfall per city/regency. Once, from the researchers' file: national monthly Sentinel-2 burned area, 2019–2024.

Processing

• Burned area is stored as SiPongi publishes it, per province and per city/regency. A year without a figure is shown as no data, not zero. A broken or incomplete SiPongi answer is refused and the previous figures stay.
• Yearly hotspots use one satellite, S-NPP, because it is the only one with data since 2015. Only detections NASA marks as vegetation fires are counted; volcanoes, fixed land heat sources such as factories, and offshore flares are excluded. These counts are never added to the 24-hour NOAA-20 counts on the hotspot page.
• Yearly hotspots are counted from FIRMS standard-quality data, which NASA reprocesses and which usually lags by a few months. The current year is counted up to the latest available day, and that date is stated.
• Each hotspot belongs to exactly one city or regency, by the same rule as the hotspot page. A province's figure is the sum of its cities and regencies.
• SiPongi only publishes the total for the year so far. Since October 2026 we keep that total each time SiPongi adds a month; a month's addition is the difference from the month before. Months before we started recording cannot be filled in.
• Firefighting reports are read again in full every 6 hours. Reports dated after today, exact repeats, and areas over 5,000 ha for one report are not used, as they are typing errors in the source.
• How NASA maps burn scars (MODIS MCD64A1): the Terra and Aqua satellites image the ground daily, and NASA's method looks for 500 m cells that suddenly turn darker in infrared light than on the days before, matched with nearby active fires. Each burned cell gets the day it burned.
• How we count it: each month we read the 17 MCD64A1 map sheets covering Indonesia. Every cell with a burn date counts as its own area, 21.47 ha, and goes to the city or regency its centre lies in, using BIG's boundaries. A month counts only when all 17 sheets are present; a year with months missing is still shown from the months present, with the missing months named.
• Sentinel-2 area is the researchers' national figure per month, used unchanged. A year is added up only when all 12 months are present.
• CHIRPS rainfall (cells of about 5 km) is averaged for each city/regency from the cells whose centre lies inside its boundary. A city smaller than one cell takes the cell at its centre. National and fire-zone means are weighted by cell count, so larger areas weigh more.
• The fire zone is the cities/regencies with the most NASA burned area that together hold 80% of NASA's burned area in its complete years. Dry-season rain is the zone's total rain over July–October.
• The peak month is the month with the most NASA burned area in a year, only for years with all 12 months. A season ends in the first month after the peak whose area is under 10% of the peak.
• Yearly hotspots of other kinds (static land heat sources, volcanoes) are counted separately from NASA's kind tag and shown on their own, never added to vegetation fires.
• The 30-day comparison uses the 30 full days before today: NOAA-20 hotspots per city/regency, ISPU from the CAMS model's 30-day mean PM2.5, and the mean daily maximum temperature and total rain from Open-Meteo. Missing figures are not counted as zero; an area's rain is used only when every day is present.

Limitations

• Burned area is an indicative figure from the Ministry of Forestry, calculated from satellite imagery. The current year's figure is still growing, and SiPongi's city and regency figures do not always add up to its province figures; we show both as published.
• Hotspots and hectares measure different things: a hotspot is a satellite heat detection, hectares are burn scars. One cannot be converted into the other.
• Small fires, or fires under cloud and smoke, can be missed by satellites, so they count in neither the area nor the hotspots.
• Firefighting reports come only from the working areas of Manggala Agni crews, mainly in Kalimantan and Sumatra. They record the crews' work, not every fire, and their areas are not added to SiPongi's burned area.
• NASA's cells are 500 m, so small fires are often missed. The copy we read lacks some months (for example September 2023 and much of 2025); those years come only from the months present, so they are lower than they should be, and the missing months are named.
• Sentinel-2 area exists only for 2019–2024 and only as national figures.
• CHIRPS rainfall is an estimate from satellites and stations, not a gauge in every place, and is published a few weeks after each month ends.
• 24-hour hotspots have no kind yet, so industrial heat sources are still counted in the 24-hour figures and the 30-day comparison.
• Air and temperature are model output. We have only started storing their history per city, so years cannot be compared yet.

Sources and licenses

• SiPongi: indicative burned area
• NASA MODIS MCD64A1 (burned area)
• Sentinel-2: Gaveau, Descals & Salim (2026)

Licence & usage

Burned area from SiPongi, Ministry of Forestry, with its source named. NASA data may be reused with attribution to NASA. Sentinel-2 area from Gaveau, Descals & Salim (2026), CC BY 4.0. CHIRPS is in the public domain; we still credit the Climate Hazards Center.