Simple ground temperature chart card

Who it’s for

Farmers and agronomists monitoring field conditions ask “how has the soil temperature changed over time, without the clutter of delta comparisons?” They want to see the current reading and a trend line in one card, nothing more.

What it does

A sensor currently reading 12°C shows a color-coded value above a chart that reveals whether the ground is warming toward planting range or cooling toward frost risk over the selected period.

• Large current ground temperature in the center, color-coded across seven bands from Very Cold to Very Hot
• Time-series chart of ground temperature readings over the selected time window, averaged per interval
• Shows one sensor’s data; it does not compare multiple field zones or show period-over-period deltas

How to set up

Data keys

Key	Role	Type	Description
temperature	Chart series	Timeseries	Ground temperature in °C; drives the chart. The Latest value overlay is automatically derived from this same key
Latest	Latest value	Timeseries	The headline figure above the chart. Its own color ranges are where the band colors are edited

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.

If the key has never reported for the selected time window, the chart is empty and the value overlay shows no data.

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 the color ranges on the Latest data key; adjust the seven default bands to match your crops’ requirements.
• To switch to Fahrenheit — set Units to °F and update the color range boundaries to match.
• To hide or show the chart — toggle Show chart in the widget settings.
• To change the chart line color — set Chart color.
• To show min, max, or total in the legend instead of avg — edit the Legend settings.
• To hide the entity name subtitle or the timestamp — turn off Show subtitle or Show date.
• To match your dashboard’s fonts — set the font options under each data key’s appearance settings.

Tips

• Use this card when the trend shape matters more than the exact period-over-period change. Add the full ground temperature chart card if you need a delta percentage alongside the chart.
• A rising line in spring signals improving planting conditions. A falling line in autumn warns of approaching frost risk.