High UV Reading and low batteries

Ive had my Air for a few months, only put cheap batteries in since I though Id wait until I get the Sky
Now the Sky has arrived I put better quality alkaline battery’s in, only to find after two weeks both are around 2.90V Seems the better quality batteries aren’t quite what they seem
Also like many other my UV reading seem way off. Despite it being winter and the expected UV is 1-1.5 mines peaked over 6 today, which is totally unrealistic. All of the other sensors seem correct

Hello Garry

Weatherflow does insist to use the following batteries as they really last way longer.


Regarding UV, indeed it could be your Sky isn’t calibrated yet. But it could help those that can do this calibtation, to share your station identification :wink:

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I’m just on my way to buy some o these now :slight_smile:
My station is 2403, easy to find the only one in Central Victoria, Australia

I must admit my UV readings are too high (winter here too, NZ)
I have been getting readings up to 5
that was not a problem with the pre production SKY units I was testing from memory

sounds like a factory calibration error with certain batches I think
should be fixable via a firmware update maybe

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@garry @weather-display, I’ve just added both of your SKY units to the UV continuous learning (QC & auto-calibration) beta group. Look for those UV values to improve soon.


great service :slight_smile:

great thanks, the Air and Sky are both performing well. The values (apart from UV) are much closer to realist local values than any other weather station Ive owned Ive made up a screen for the Air which is based on idea posed here, Will upload some pics if anyone is interested


Thanks @garry. I’m confident you’ll be seeing better UV values soon. Please do post pics of your radiation screen; there’s a thread over here where others are doing the same: Photos of Air and Installation

It looks like I might have the same problem with the UV & Solar readings.
I’m using my weatherflow next to some brand new Davis sensors.

  • UV reading Davis: 2.3
  • UV reading WF: 7.5

Same for the Solar Radiation.

  • Solar reading Davis: 365 W/m²
  • Solar reading WF: 561 W/m²

It might be an idea to make a 10 minute running average reading for the UV sensor, which should bring more reliable and stable data. That said, I still think it’s reading is too high, as an UV index of 7.5 is very unlikely in Belgium. My Sky is on FW version 43 and hub on 94.
Station number 5373.

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Can support have a look and squeeze the readings back to normal ?? :hugs:

Hi Bert. Your solar data should improve soon. It usually takes a few days for the auto-calibration process to gather enough data to suggest a change.

Mine is is still insanely high after a month uptime, FWIW…no way the UV rating gets that high near Seattle.

weewx graph for the last month…


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I just checked and it looks like the CL system updated your UV cal over night. The new calibration results in a reduction of roughly 60%, so you should see more sane values starting today.