A compost pile should reach an interior temperature of 140°F or more to effectively kill weed seeds and pathogens. If the pile is not reaching this temperature, adjustments can easily be made to its moisture content, pH, aeration, etc., to bring it up to the proper temperature. Although you can stick your hand into the pile to see if it is "hot" or not, that is not a reliable measure.
This compost thermometer has an extra-long 20" probe to reach down into the middle of the pile for a quick and accurate reading. The easy-to-read dial face measures from 0° to 200°F, and has markings to indicate decomposition speed zones. Organic matter decomposes slowly in the Steady Zone (80° to 100°F), faster in the Active Zone (100° to 130°F), and most rapidly in the Hot Zone (130° to 160°F)
Made of stainless steel.
The compost thermometer is also available as a set with our compost moisture meter.