Simple UV Index chart card

Who it’s for

Public health managers, outdoor venue operators, and school safety coordinators ask “how has the UV index changed over time, without the clutter of delta comparisons?” They want to see the current index and the daily curve in one card, nothing more.

What it does

A sensor currently reading 6 shows an orange value — High — above a chart that reveals the day’s UV curve: near zero at dawn, climbing through mid-morning, peaking around solar noon, then falling back through the afternoon.

• Large current UV index value color-coded across five bands from Low to Extreme
• Time-series chart of UV index readings over the selected time window, averaged per interval
• Shows one sensor’s data; it does not compare multiple sensors or show period-over-period deltas

How to set up

Data keys

Key	Role	Type	Description
uv	Chart series	Timeseries	UV index (dimensionless); 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 UV Index, 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	Level	Color
0–2	Low	Green
2–5	Moderate	Orange
5–7	High	Orange
7–10	Very High	Red-Orange
10+	Extreme	Red

How to customize

• To use your own UV thresholds — edit the color ranges on the Latest data key; adjust the five default bands to match your public health advisory thresholds.
• To hide or show the chart — toggle Show chart in the widget settings.
• To change the chart line color — set Chart color.
• 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 daily UV exposure curve matters more than the exact period-over-period change. Add the full UV index chart card if you need a delta index-point figure alongside the chart.
• The UV index drops to zero after sunset; a non-zero overnight reading indicates sensor noise or a calibration issue worth investigating.
• Pair with a solar radiation simple chart card to compare the two curves — on a clear day they track closely; divergence (high UV, lower irradiance) may indicate atmospheric scatter conditions that still expose people to elevated UV despite reduced visible light.