Ice Age Farmer:
Grand Solar Minimum
Growing Degree Days Tool
Modern agriculture is at risk due to cyclical changes in our sun's output that drive climate change on our planet.

This page tracks the change in Growing Degree Days in the US between 2018 and 2019

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Growing degree days (GDD) are a measure of heat accumulation used by horticulturists, gardeners, and farmers to predict plant and animal development rates such as the date that a flower will bloom, an insect will emerge from dormancy, or a crop will reach maturity.

In the absence of extreme conditions such as unseasonal drought or disease, plants grow in a cumulative stepwise manner which is strongly influenced by the ambient temperature. In other words, GDD values provide a best case outlook as to plants' pace to maturity. (wikipedia)

As we enter the Grand Solar Minimum, temperatures are decreasing. The data should demonstrate this. I have created this tool to analyze the drop off in GDD between 2018 and 2019 seasons across the US.

ZIP or state code:
CountyAverage Change in GDD2019 GDD% of 2018
Alameda-153.412194.26-6.53 %
Alpine-309906.5-25.42 %
Amador-252.452843.86-8.15 %
Butte-412.223215.53-11.36 %
Calaveras-305.972527.39-10.8 %
Colusa-671.073902.07-14.67 %
Contra Costa-253.772516.03-9.16 %
Del Norte-88.381409.38-5.9 %
El Dorado-397.822145.27-15.64 %
Fresno-441.894014.89-9.92 %
Glenn-637.083808-14.33 %
Humboldt-129.291368.01-8.63 %
Imperial-818.376188.4-11.68 %
Inyo-883.053606.55-19.67 %
Kern-500.93563.71-12.32 %
Kings-504.434651.43-9.78 %
Lake-460.932754.36-14.34 %
Lassen-458.321803.04-20.27 %
Los Angeles-631.463322.97-15.97 %
Madera-404.083215.63-11.16 %
Marin-190.691762.66-9.76 %
Mariposa-360.692495.44-12.63 %
Mendocino-121.291916.48-5.95 %
Merced-332.164114.45-7.47 %
Modoc-416.051757.55-19.14 %
Mono-4071361.79-23.01 %
Monterey-70.472201.95-3.1 %
Napa-416.552731.8-13.23 %
Nevada-412.192483.88-14.23 %
Orange-634.833321.57-16.05 %
Placer-381.132436.42-13.53 %
Plumas-398.871674.67-19.24 %
Riverside-853.963906.02-17.94 %
Sacramento-269.963405.24-7.35 %
San Benito-244.382583.63-8.64 %
San Bernardino-835.213405.94-19.69 %
San Diego-558.263172.24-14.96 %
San Francisco-176.52025-8.02 %
San Joaquin-178.083378.73-5.01 %
San Luis Obispo-371.142460.67-13.11 %
San Mateo31962.080.15 %
Santa Barbara-313.412731.87-10.29 %
Santa Clara-0.282066.97-0.01 %
Santa Cruz44.122182.322.06 %
Shasta-495.652703.94-15.49 %
Sierra-392.811444.75-21.38 %
Siskiyou-291.351646.61-15.03 %
Solano-373.52794.1-11.79 %
Sonoma-218.812200.01-9.05 %
Stanislaus-284.173785.98-6.98 %
Sutter-458.53890.56-10.54 %
Tehama-473.773339.46-12.42 %
Trinity-316.271960.42-13.89 %
Tulare-366.893656-9.12 %
Tuolumne-417.652093.5-16.63 %
Ventura-642.462834.33-18.48 %
Yolo-545.253571.08-13.25 %
Yuba-443.042910.54-13.21 %
CA state avg: -385
States:Cities:
  • CO by county
  • IN by county
  • NH by county
  • IA by county
  • Puerto Rico
  • Taos, NM (-47%)
  • Westcliffe, CO (-43%)
  • Marquette Co, MI (-43%)
  • Sublette Co, WY (-44%)