Heat Index and Dew Point become unavailable, when RH goes above 100%.

[darrenfreeman]

Some sensors can report a relative humidity above 100%, particularly when it's raining, and especially if the sensor has a calibration applied.

I noticed a chart of Heat Index and Dew Point with a range of missing values, despite the sensor being available. This appears to be caused by the relative humidity of about 101%.

It would be better to clip these small excursions to 100%, and continue with the calculations.