Rainfall measurement is wildly inaccurate

I am a new owner and observer. I find the haptic rain monitor/sensor to be extremely off. I’ve suspected it for some time, now I’ve confirmed it. I have a CoCoRaHS rain gauge to compare to - last night the Tempest reports we got .38", we actually got .87". That’s off by over half. It’s said it somehow calibrates itself eventually, how long does this take? The station has been installed for a month now. We’ve had two heavy rainfalls, some light between (or so I think - they may have been heavier here, happened when I was at work).

Last night’s rain was torrential, during a thunderstorm.

Would like to know also

If you want to speed up the calibration you can report your rain results as stated in this thread: SKY/Tempest vs. co-located rain gauge” reporting,

I’ve had that enabled since day one. Doesn’t seem to be doing much.

Take care,


I can’t seem to get past the station ID. My station says on my web interface page the ‘share link’ is https://tempestwx.com/station/19623, but it keeps asking for a valid station ID.

Your Station ID is just the number part in that link: 19623.

Perfect, thank you!!!

Interesting, I’ve just checked, and it’s up to .52 from earlier today - there’s been no additional rain, so something adjusted. Still isn’t right though. I’m entering data in the Rain Check system now. Thank you all for your help!

You’re welcome. I have found that it takes several rain events and with varying intensities for the calibration to get reasonably close.

The adjustment you are seeing is from RainCheck running as can be seen by the rain drop with check mark: image . You can turn this on/off in the Advanced menu for the device settings.

I have two Sky devices an old and new device both showing very different readings. I reset them about 10-minutes apart (I think early April 2020) but unfortunately did this incorrectly so I lost all historic data!!!

The UV, brightness, solar radiation are all completely different. I have my old Vantage Pro setup next to these and I trust those readings (rainfall) way more. Wind is also out when comparing the two units. Understandably the location of installation will affect this so some degree, but I’d not expect by huge amount especially with higher winds.

Today (at the time of writing) the Vantage Pro indicated 2.8mm rain and both Sky units showing zero rain.

I don’t know which device to trust. https://tempestwx.com/station/2434/grid