Contra Calor

Track Growing Degree Days for any vineyard, anywhere. Station-accurate GDD and Winkler classification for viticulture professionals.

Contra Calor is the viticulture Growing Degree Day tracker built for wine professionals. Pin your vineyard, pick your vintage, and get station-accurate heat accumulation data in seconds.

WHAT IS GDD? Growing Degree Days (GDD) measure the heat accumulation a vineyard experiences during the growing season. GDD is a primary metric viticulture professionals use to predict grape maturity, plan harvest timing, and benchmark vintages year over year.

HOW IT WORKS Drop a pin on your vineyard — anywhere in the world. Contra Calor pulls station-priority weather data from a global network of NOAA, ASOS, and personal weather stations, calculates your GDD accumulation from April 1 through October 31 (or set your own custom date range), and classifies your site on the Winkler scale.

VALIDATED ACCURACY Independently validated against CIMIS (California Irrigation Management Information System) stations and Weather Underground personal weather stations across Napa Valley, Sonoma, and the Sierra Foothills. Average variance: 1.5–3.8% against ground truth data.

FEATURES

• GDD calculation for any vineyard location worldwide
• Winkler region classification (Regions I–V)
• Save vineyard profiles with nested vintage history
• Compare up to 3 vintages side by side
• Accumulation curve chart for each vintage
• Northern and Southern Hemisphere support
• °F and °C toggle
• Works offline after initial calculation

CONTRA CALOR PRO Upgrade to Pro for unlimited vineyard profiles, full vintage history, 3-vintage comparison, and Southern Hemisphere support.

ABOUT THE NAME Contra Calor — Spanish and Latin for both "Against the Heat" and "Counting Heat."

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