Compost Thermometer. Not this one necessarily just an idea
Regulating Temperature in a Worm Bin. Learn the ideal temp for red wigglers and how to raise or lower the temperature in your worm bin
Winter composting - Compost Thermometer by fishermansdaughter
Compost Thermometer. You Really Need One Of These.
Workshop Homesteading Featured Instructables - Explore the Biggest How To and DIY community where people make and share inspiring, entertaining, and useful projects, recipes, and hacks.
REOTEMP FG20P Backyard Compost Thermometer - 20" Stem, Fahrenheit with Composting Instructions
It's spring, but is it time to plant? Using a thermometer to take soil temperature is the best way to know.