Ground temperature card

Who it’s for

Farmers, agronomists, and environmental monitoring teams ask “is the soil warm enough for planting, or is there still a frost risk?” Ground temperature determines when seeds can germinate, when roots grow, and when the soil is in danger of freezing — a number that matters as much as air temperature for anyone managing crops or land.

What it does

A sensor reading 8°C shows a light blue icon and value — Cool, suitable for cold-tolerant crops. The same card turns orange at 15°C — Moderate, good for most spring plantings — and orange at 25°C — Warm.

• Color-coded icon and value that change across seven temperature bands, from Very Cold to Very Hot
• Auto-scaling layout that fits any card size
• Last-updated timestamp showing how long ago the reading arrived
• Shows one sensor’s data; it does not chart trends or compare multiple field zones

How to set up

Data keys

Key	Role	Type	Description
temperature	Main value	Timeseries	Ground temperature in °C; change the key name to match your device’s telemetry key

The widget ships with a simulated function datasource key labeled Ground temperature, so it draws random values until you point the datasource at a device and rename the key.

To point it at your own device: open the dashboard in edit mode, open the widget’s Datasources, pick the entity or entity alias, and replace the function key with the key your device reports.

The card shows the value in °C with one decimal place. If the key has never reported, the card displays the label and icon with an empty value, not an error.

Value ranges

Range (°C)	Level	Color
< −20	Very Cold	Deep Blue
−20–0	Cold	Blue
0–10	Cool	Light Blue
10–20	Moderate	Orange
20–30	Warm	Orange
30–40	Hot	Red-Orange
40+	Very Hot	Red

How to customize

• To use your own temperature thresholds — edit Icon color ranges and Value color ranges; set the same boundaries in both so the icon and the number always agree.
• To switch to Fahrenheit — set Units to °F and update the color range boundaries to match.
• To change the icon — set Icon to any Material or MDI icon name.
• To reposition the label — change Label position to top, bottom, left, or right.
• To hide the label, icon, or timestamp — turn off Show label, Show icon, or Show date.
• To switch to an absolute timestamp — turn off Last update ago in the date format settings.
• To match your dashboard’s fonts — set Value font and Label font.

Tips

• Keep Icon color ranges and Value color ranges on the same boundaries so the icon and the number always show the same band.
• Most vegetable seeds germinate reliably at 10–20°C. Below 5°C growth stalls for warm-season crops; above 35°C heat stress sets in for roots.