GDD Tracker

Growing Degree Days measure accumulated heat since early spring. Insects, diseases, and weeds hit predictable thresholds as heat builds — this tool tells you where you are and what is coming.

Cumulative GDD (Base 50F)
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Select a city above to see thresholds.
Method: Simple average GDD (Tmax + Tmin) / 2 - 50F, floored at 0. Thresholds sourced from MSU Extension, Wayne County Extension, and regional university IPM programs. Weather data via Open-Meteo. Oakland thresholds are approximate — calibrated for Midwest climates.