Heat Unit Calculator

Select weather stations, dates, and heat-unit models to calculate accumulated crop development units.

Independent branch

Separate from potato and multi-crop dashboards

Uses the same underlying station weather archives already published in this project.

Calculator setup

Choose one or more stations, a date range, and the heat-unit models you want to calculate.

Loading stations...

Search stations Weather stations

Hold Command on Mac to select multiple stations.

Start date End date

Heat-unit models

GDD
Growing Degree Days CHU
Canadian corn heat units Potato P-days
Physiological day response Chill hours
Hourly when available, otherwise estimated daily chill PTU
Photothermal units = GDD × day length

Model parameters

GDD / PTU base Tmax cap Chill method

Advanced P-day settings

P-day base (°C) P-day optimum (°C) P-day upper cutoff (°C) P-day peak units/day

Choose stations and click Calculate.

Results summary

Accumulated totals by station and selected model, with missing-data context for each result.

No calculations yet

Station	Start date	End date	Unit type	Accumulated value	Days included	Missing days	Status
No calculations yet.

Daily details

Daily temperatures, daily heat units, and cumulative totals for each selected station and model.

No rows

Date	Station	Tmax	Tmin	Unit type	Daily value	Accumulated value	Data note
No calculations yet.