Dashboard root

Heat Unit Calculator

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

PEI weather stations

70 mapped stations

EPAA (1)UPEI (46)PEI Department of Agriculture (13)Private (2)Government (8)

Click the map to open a larger view. Hover over a station marker to see its name.

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.

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Decision-support only: Model outputs depend on weather data, user inputs, and biological assumptions. Verify results with field scouting, local field conditions, product labels, agronomic advice, and applicable regulations before acting.

1Search stations

Search and choose stations with checkboxes. The hidden technical selector stays synced for the calculator logic.

2Start date 3End date

4Heat-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

Before acting on this report, confirm crop stage, field conditions, scouting observations, product labels, and local regulations.

Choose stations and click Calculate.

Results summary

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

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Station	Start date	End date	Unit type	Accumulated value	Days included	Missing days	Status
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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.