Humidity always reads 100% in the early morning

My Humidity reading is always 100% on nights that are clear and calm. My wet bulb and dry bulb temperatures are always the same. If I check other local weather reports, their humidity readings are lower, usually in the upper 80% to the mid 90%. Could condensation on the Tempest cause it to report 100%?

condensation should not happen but many elements can influence. Is it nearby vegetation ? Or something that generates a lot of humidity at night ??? Sprinklers, water …

Also I see there is no calibration yet to your sensors … seems to be up recently so it might take a few more days to kick in.

My Tempest is located on a ten foot pole attached to my roof. It is not near anything like vegetation or something that generates a lot of humidity.
Can you explain how to find the calibrations to my sensors? I am not sure I understand what you mean.


You can’t see nor influence actively continuous calibration of several sensors. It is done automatically every x times on all stations.

Depending what sensor, other data or internal data is used to see if it is ok (QC in some way)
And when it sees things that aren’t ok, it will apply a ‘calibration’ to make it better. But this isn’t instant nor on a regular basis. It happens (first changes might be very visible but over time the adjustments are micro)

In your case none were done as your unit is pretty new. Some need about 10 valid measurements (over several weeks) to kick in, others happen within 2 weeks … in your case your humidity is indeed too high but calibration will handle that soon.
Devices get a default value in factory but those are good in some areas and way out in others, hence this continuous calibration process to bring it in line with your siting. It just needs a little time to learn.

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tell me how! relative humidity is defined the same everywhere. The sensor is virtually insensitive to barometric pressure, so why would a good factory calibration not be valid all over the world.
Now there might be other reasons why it needs calibration but the area shouldn’t matter… I think.

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