Simple rainfall chart card

Who it’s for

Farmers, city flood managers, and environmental monitoring teams ask “how has rainfall 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 4.2 mm shows a dark-blue value — Moderate — above a chart that reveals whether rainfall has been building through the day or tailing off after a morning event.

• Large current rainfall value color-coded across four bands from None to Heavy
• Time-series chart of rainfall readings over the selected time window, averaged per interval
• Shows one sensor’s data; it does not compare multiple gauges or show period-over-period deltas

How to set up

Data keys

Key	Role	Type	Description
rainfall	Chart series	Timeseries	Precipitation in mm; 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 Rainfall, 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 (mm)	Level	Color
0	None	Light Blue
0–2.5	Light	Medium Blue
2.5–7.6	Moderate	Dark Blue
7.6+	Heavy	Deep Blue

How to customize

• To use your own rainfall thresholds — edit the color ranges on the Latest data key; adjust the four default bands to match your operational or agronomic thresholds.
• 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; total is often the most useful aggregation for rainfall.
• 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 rainfall chart card if you need a delta mm figure alongside the chart.
• Switch the legend aggregation to total to show cumulative rainfall for the selected window instead of the average reading per interval.