Dew Point

[Dennisdg]

Cumulus MX Dashboard is reporting the Dew Point at 17:03 as - 10.2 deg C. This looks low to me. The local airport (4 miles away and in line of site, no hills in the way) shows -1 deg C. AccuWeather shows 0 deg C.
The humidity is low, the pressure is high, no clouds.

I'm using my Davis Vantage PRO2 to provide the data. Changing to Cumulus value instead of station, saving, and restarting Cumulus shows a very similar negative value to Davis.

Any ideas on what to check if anything.

Thanks

[freddie]

It looks as if your humidity sensor may be on the way out. Although large areal differences in humidity (and hence dewpoint) are possible in the current conditions during the day, I think that your overnight humidity maximum of 70% is far too low - 90% would be a more realistic maximum, perhaps even 95%. The under-read is particularly likely seeing as you had light or calm winds for part of the night too.

[Dennisdg]

Thanks Freddie

I'll take a look at cleaning the radiation Shield this weekend, it may be full of stuff- the weather should be kind. I'll start searching for a replacement sensor.