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



@caredlands Per our email: our engineers suspect either a bad/mismatched battery or you mistakenly put one in the wrong direction causing a drain. Here is what a normal SKY battery curve looks like: https://smartweather.weatherflow.com/share/1934/graph/7267/battery/5

Never fear, we are sending you a fresh pack of Energizer Ultimate Lithiums. Make absolutely sure to insert all batteries in the right directions per: got.wf/swsbatteries

In “performance” mode with 3sec wind samples, good batteries in SKY should last approx 8-14months. In “power saving mode” with 20sec wind sampling the batteries in SKY should last years. In the new v2.0 app, you can set SKY power mode: App > Settings > Stations > [select station] > Manage devices > [select SKY] > Advanced > Power mode toggle.

SKY: power save mode = 2yrs+ battery life

Is 35mm rod still OK for the Sky? I’d like to use aluminum because it is lighter than steel.
Thank you.


SKY mount is 32mm. See: Post Photos of Sky Installation


Just installed my Sky and went through the first rain event. Few observations.

Installing Sky did create a minor rainstorm which I successfully was able to delete from the archives.

There was one very brief/minor rain event registered to Sky yesterday afternoon that did not happen. Bird? (I have added no bird protection measures yet but probably needed due to high local bird population.)

There appeared to be several rain started messages from the App when there was no rain observed and also not reported on Sky.

There was at least two minor sprinkle events that did not fully wet the pavement that did not trigger a reading in Sky.

It rained overnight with Sky registering around 0.46" inches of rain while my Cocorahs rain gauge located about ten feet away registered about 0.19." (Wind was low through the event generally less than 10 mph. FYI my impression on wind readings so far is that it appears to be a little low but could be accurate based on less than perfect siting. I think the wind gust chart seems to reflect airport wind average pretty well based on initial observations so pleased with that.) At one point, I noted that it read “extreme” which I myself would have classified as a moderate heavy downpour. (Edit: Total storm total per Sky 2.45". Actual rain gauge reading 0.87".)

See attached photo of Sky. It is 7 or 8 feet off the ground on a small ridge overlooking a very large field. I used a 10 foot high fence post from Home Depot per recommendations found at this site and installation was quick and easy. The metal pole was cemented into the ground and appears to lack any vibrations.

I understand that there will be a calibration period for Sky to go through so will be interesting to see if the initial overestimate of rainfall goes away in subsequent events which should come later today, possibly tomorrow and couple times next week. (Note: I was one of the lucky winners of receiving 2 SKY units for the price of one! :slight_smile: I do plan on returning it after I receive a prepaid postage from WeatherFlow as I would hate for somebody else having to wait any longer than necessary for their unit!)


David I have been getting false rain readings on one of my units. Seems to be when we get wind greater than 15-20. My other sky in a different locations doesn’t seem to have the same issue. Read over 10 inches in 24hrs with clear skies. Mounted on a 1 3/8" by 10’ steel pole cemented into the ground with no obstructions.
I’m more concerned with the wind readings in this location but figured you would want feed back to correct this issues.


@ esolway, that sounds like wind vibrations in the steel pole causing false rain
you might want to look at using a pvc pipe for the last few feet somehow maybe?


We got two batches of rain totaling 14.5 mm recently - old method with measuring cylinder.
The SKY got exactly the same. There was a mixture of very heavy and very light rain in that time. Well done weatherflow! I’m happy so far.


Elliot, there’s definitely something causing vibration or other movement to your new SKY. Is there any way to stiffen the mount?

@goldentsunami thanks for the detailed report - it is Field Tester worthy! Keep it coming - you should see improvements over time.

Glad to hear it!!


Hi David
Thanks for the reply. Sky is on a steel pole and it does sway a little in strong wind. Very tight fit at the mount. If the sway is the problem could try guide wires


Wowzers, for those seeing incorrect rain, I think I’m in the same boat. I installed my Sky on the 6th, and today we’ve had our first big rain event. When the storm started, the WeatherFlow instantly switched to EXTREME indication of 18.792 in/hr! I know it was raining hard, but I don’t think it’s quite time to build an ark just yet!

In the same peak, my Ambient Weather WS-1001 Wifi installed 30 feet away was recording 1.98 in/hr, which is still a crazy large amount of rainfall, but much more believable. At this point, it’s recording 2.595 in of rain in the past hour. My WS-1001 is reporting 0.48.

I’ll let everyone know what the final totals are after the storm has passed. Is this normal during the calibration process? And more importantly, is there any way that I can help improve the process?

Edited to add: Also, I know there are buggy issues with WeatherUnderground, but it seems like the WeatherFlow station is reporting incorrect data to WU. It’s reporting a rainfall rate of 2.65 in/hr, which I believe corresponds to the Rain in the Past Hour reading from WeatherFlow rather than the last hour. Is this a known bug?


having a user adjustable calibration for the rain sensor might be a solution?


New Sky user here. I have noticed that mine is reporting very high amounts of rain as well. I had 2 rain events yesterday, 6/10/18, that were measured with a couple of traditional rain gauges at the same location. The event starting at 2:15am recorded 2.737" and my other gauges recorded 0.6". The even at 12:05pm the same day recorded 2.245" and my other gauges recorded 0.5"

I received my Sky on 6/7 and set it up that evening. I had a couple of rain events the next day that seemed to be measuring high, but I did not have the additional gauges set out at the time.

Here is my station’s rain data: https://smartweather.weatherflow.com/station/1731/graph/9125/rain/2

Is mine still learning, or is it in need of calibration?



I am showing higher-than-expected rain rates in a moderate rainstorm with the SKy v2:


If you do Build an Ark, please credit me. :smile:


As a follow-up to a previous post where basically the first rainfall event was too high by something like 285%…yesterday’s rainfall on Sky compared to a standard rain gauge was exactly the same…0.06" so encouraged that whatever is being done to calibrate the device is working.I will watch a few more events carefully to see if there is any change.


Hello. I am seeing my sky report much higher rain levels then expected. No false detections which is great but when it actually does rain it shows quite height rain rates compares to my old Lacrosse. I expect the sky to be a little more sensitive but these just seem too high.



Thanks for your reports here, folks. We’re actively tracking these issues and learning a lot from all the new data coming in. We’re finding that the specific installation conditions can have a significant effect on the rain sensor calibration. You should expect to see some odd rain data for a while as we work what the humans are learning back into the machine learning algorithms that keep your stations calibrated. Your data will get better soon!

split this topic #60

3 posts were split to a new topic: Negative Rain display?


I was getting a few false readings in my initial mounting location so I moved my sky unit on Monday. I did delete all the rain data through the app to start anew. I’ve been checking my data against a rain gauge about 20 feet away and nearby stations and my unit is reporting on average twice the amount of rainfall. Should I expect more ‘learning’ to occur or is something else needed? Thanks!


Yesterday I around 8:30 EST my sky was showing .611" of rain, my rain gauge was showing .25" and a weather station about a mile away was reporting .3".