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GDD Accumulated So Far — By ZIP Code
Enter your ZIP code, crop and season start date to pull real accumulated growing degree days from historical weather — no manual daily log.
Your numbers
Result
Enter your ZIP code and season start date, then tap Calculate.
How it's calculated
GDD = (daily high + daily low) ÷ 2 − base temperature, summed over every day from your season start date through today, never less than zero per day. Corn additionally caps the high at 86°F and floors the low at 50°F before averaging.
Unlike the other heat-unit calculators on this site (which take a high/low you type in), this one pulls the real historical daily high and low for your ZIP code's location from a public weather archive and adds them up automatically — no daily log to keep.
Historical weather archives typically lag ~5 days behind today, so the most recent few days may not be counted yet.
Row Wise tracks accumulated heat units automatically for your actual field boundary all season — plus growth stage, spray windows and irrigation timing in one place.
Get notified at launch →Frequently asked questions
How is this different from the other heat-unit calculators?
The cotton and corn heat-unit calculators on this site take a single day's high and low that you type in. This one instead looks up your ZIP code's real weather history and adds up every day of the season automatically, so you don't have to log daily temperatures yourself.
Why does it need my ZIP code?
The ZIP code is used only to look up your location's latitude and longitude (via a public ZIP-lookup service), which is then used to pull that location's real historical weather. Nothing is saved — it's a lookup, not a signup.
Why might today's temperature be missing?
Historical weather archives are usually a few days behind real time. If today or yesterday looks low, that's likely because the archive hasn't caught up yet, not a data error.