Rain seem off (auto-calibration system not yet deployed)



I noticed my Sky is also sensing too much rain, even with fw V94.

Yesterday Sky showed about 20 mm (that is much higher than official Stations claim)

Today so far the same perception, Sky 25 mm vs about 6 mm nearby station on WU.

Very high rainfall amounts. How to calibrate Sky?

@eric I’m not shure but maybee i should have posted these topics in the other topic (Rain Gauge Reading Seem Off (auto-calibration system not yet deployed))
edit : moved (eric)
If so, please move my 2 topics to the other one. thx :+1:

Today same issue, if I look into my data vs f.e. @spacesnow (not far away) the idea is that my Sky registers roughly about 10 times too much.
There was almost no wind, just a lot of rain.

The Sky from Spacesnow seems to be ok.

I’ve read several topics, but couldn’t find any solution yet.



2 options

your sky is indeed having a hardware problem though mostly it doesn’t sense anything

your sky seems to give false rain for some reason, mostly vibration. Is there any correlation between the moments you have rain and wind being high ??
Is there a possibility some nasty tweety is tap dancing on your Sky ??


It does sense rain, but from what I have calculated against another station nearby, maybee a Davis, it is about 10 times the official amount.

No birds today, although the option crossed my mind, even those animals aren’t that stupid to go fly in such rainy days. :parasol_on_ground:

WU Eerbeek - The Netherlands

Pressure1016.59 hPa
Visibility6.44 kilometers
Dew Point8 °C
Rainfall10.41 cm
Snow Depth0 cm
Metar data not available [/QUOTE]


Mister blackbird

could you please do this, that way it is easy for us to hop to your station and have a closer look. For now I can just try to guess where you are in Nederland :wink:


Thanks for your report. As noted above, the v94 firmware improves the default calibration but you will continue to see some strange numbers until the next step, which is to activate the auto-calibration routines for individual stations. This rain component of our continuous learning system is still being tested and is NOT affecting your SKY yet. Stay tuned!


@eric @dsj As requested job done!


FYI: Maybe my wind amounts are not correct, I haven’t found a correct location and it isn’t that important for me


Since the upgrade to 94 firmware the Sky unit has switched from grossly overestimating rainfall to now underestimating between 40-60% mostly dependent on rate. So a very light rainfall of say 0.01 - 0.02 in/hr will show as within the error of my tipping bucket rain gauge. If the rate is closer to 0.5" per hour, then the two begin to diverge with the tipping bucket reporting nearly twice as much as the Sky unit. With really heavy rainfall (say 3"/hr which we get with alarming frequency in Houston these days), the sky initially reports more than the tipping bucket, but then the tipping bucket “catches up” and ends up reporting roughly twice as much as the Sky did.

The tipping bucket has tracked the NWS doppler estimates pretty closely for at least the past five years, and continues to be within about 20% of their estimate - I am located 13 miles line of sight from the radome.


Last few days of light rain here comparing VP2 and WF - funny seeing when the Davis tipper tipped…

C’mon calibration - the rainy and windy season is here !


Today we had our first drop of rain since I received my weather station in late August. I shouldn’t say “drop” – my station’s inaugural shower came down in buckets, registering as “Very Heavy” on the WeatherFlow app.

So, if I remember correctly, it takes a couple of rain events for the Sky to calibrate itself, is that correct? Checking out other stations near me on Weather Underground (not WF stations), my station reported half of the rainfall accumulation that nearby stations reported. My app shows .29" (which we got in one hour), while neighboring stations came in at over .5". Is that to be expected until I’ve got a couple of rain events under my belt?


Calibration on rain is not yet active. Data is gathered and analysed, but the resulting calibration isn’t yet pushed to our station.


We had a heck of a rain dump overnight(sounded like the house was going through a car wash) and my station only registered 3.9mm) before this last update it would register a lot more now it’s been very conservative


Calibration on rain is not yet active. Data is gathered and analysed, but the resulting calibration isn’t yet pushed to our station.

Sooo, does that mean I can expect these erroneous rain totals to continue without the potential for improvement?

BTW, my cheesy $3 plastic rain gauge corroborated the .5" rainfall that my neighboring stations reported.


As mentioned in other topics on this forum, rain data will be better once the calibrations are rolled out to all stations. Calibration will be calculated for each station and not one for all as it is for now. . I can’t tell you when since I have no clue but according David from WF it is imminent …


They will continue for a bit longer but the potential for improvement is large.


today we had rain – went 75 days without rain –

seems like rain stats for the weatherflow have improved –

10-3-18 vue 0,01 10-4-18 vue 0.06
10-3-18 vp 0.01 10-4-18 vp 0,06
10-3-18 wflow 0.03 10-4-13 wflow 0.04

hopefully this continues correct rain stats


Received the first significant rain in three months, first since setting up my Weatherflow. Readings seem to be about half that of the surrounding stations.



On 9/27/18 a line of very strong storms moved through and continuous rain fell between 22:00 and 23:30. I noticed on my app that there were a couple times where negative rainfall was reported, and no rainfall rate was qualitatively reported. Total rainfall from the neighbor, 4 houses down with a traditional tip-bucket gauge, from that period was ~0.9", while my SKY unit only picked up on ~0.32". Rainfall rate for the SKY came in around 0.4"/hr, while the neighbor had double the rain rate. I know I will be getting a traditional cocorahs in the near future, given the discrepancy, to better compare, but I know for a fact it rained much harder and in greater quantities than it picked up on. Any thoughts?


Can you give us your station number (or link), we could have a look and also for WF staff it will be easier to locate your station.

With hub version 94 most stations under report rain. This will get better once the calibration rolls out. No, I don’t know when. :slight_smile: