The risk of severity of a fire season is a climate- and weather-based prediction, and with the aid of climate models, fairly accurate predictions can now be made. Prediction often uses climate and weather data but it also involves studying trends over time and complementing these trends with ground data. Scientists often use El Nino Southern Oscillation (ENSO) patterns to help with fire risk prediction, as fires are exacerbated by drought conditions in ENSO years. However, even in non-ENSO years, there can still be some fires.

In both South Sumatra and Central Kalimantan, the fire season lasts from July until October. During this period, water tables go down and surface fuels become very dry. Small fires that occur at the start of the fire season are less important than fires that occur later in the dry season. This is because fires that take place early in the season are less likely to transition into the soil and become peat fires (subsurface fires) as the water table is still high and the peat is still moist.

If biophysical conditions include low peat moisture content and water table depth, continuous fuel load on the surface with heavy fuel available, and high air temperature and wind speed, burning surface vegetation can ignite the peat. Smouldering peat soil can subsequently re-ignite surface vegetation, allowing fires to spread both above and below the surface.

Thus, fires in tropical peatlands are actually two distinct phenomena: fires that burn the fuel available on the peatland surface—surface fires—and fires that transition into and burn the peat soil itself, or peat fires.