The process of decomposition produces heat. A properly working compost pile,
will be warmer than the surrounding air temperature.
Compost temperatures should be measured deep in the center of the decomposing
materials. A compost thermometer is available, to take this measurement.
The Cycle of Composting Temperature Basics:
At the beginning, your compost materials will be at, or near, the surrounding
As you bring the proper mix of green and brown compost material into a pile
or a composter, the internal temperature will begin to rise.
As it moves into the "Thermophilic" period, temperatures will ideally reach
135-160 degrees F. This range will kill disease pathogens, weed seeds, spores,
If the temperatures do not reach 130-160 degrees F, add more green materials,
or a little nitrogen.
This high heat period will usually last from 3-10 days.
Keep temperatures below 170 Degrees F. Above this point, bacteria is inhibited
from decomposing materials, and the high heat can even kill essential bacterias.
The pile should be turned regularly, at least once a day. After turning the
pile, the temperature will drop temporarily.
If the temperature of the compost drops, add a little nitrogen, or nitrogen
bearing green compost
Composting Tip: A properly working compost pile should be at least
3' X 3' X 3'. This is required to obtain internal temperatures adequate to
kill pathogens and weed seeds.
Did you Know? Spontaneous combustion can occur above 180 degrees F.
If temperatures exceed 170 degrees, mix in brown composting materials, to
help cool the pile a little.