Humidity chart card

Who it’s for

Building managers, HVAC engineers, and environmental monitoring teams ask “is humidity drifting out of the comfort zone, and how fast compared to last week?” A single snapshot does not say whether dryness is building up or conditions are returning to normal; the trend does.

What it does

A sensor averaging 65% this week, up from 45% last week, shows a +44% delta in red — humidity is climbing toward the Humid band. The chart below confirms the upward trend over the selected period.

• Large current humidity value in the center, color-coded across five bands from Very Dry to Very Humid
• Percentage change vs. the previous period, with a colored arrow — red when humidity is rising, blue when falling
• Absolute humidity change in % shown below the delta percentage
• Time-series chart of humidity readings over the selected time window, averaged per interval
• Shows one sensor’s data; it does not compare multiple zones

How to set up

Data keys

Key	Role	Type	Description
humidity	Chart series	Timeseries	Relative humidity in %; drives the chart. The Latest, Delta percent, and Delta absolute overlays are 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
Delta percent	Percentage change	Timeseries	Change against the previous period, as a percentage
Delta absolute	Absolute change	Timeseries	Change against the previous period, in the key’s own unit

The widget ships with a simulated function datasource key labeled Humidity, 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 all overlays show no data.

Value ranges

Range (%)	Level	Color
0–20	Very Dry	Red
20–40	Dry	Orange
40–60	Comfortable	Blue
60–80	Humid	Dark Blue
80–100	Very Humid	Deep Blue

How to customize

• To use your own humidity thresholds — edit the color ranges on the Latest data key; adjust the five default bands to match your facility’s targets.
• 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

• A rising delta toward the Humid or Very Humid band can signal a ventilation or condensation problem. A falling delta toward Very Dry suggests heating or low outdoor humidity is drying the space out.
• Pair this card with a humidity alert rule to get notified when the trend pushes outside the 40–60% comfort window.