36 Replies Latest reply: May 6, 2013 8:33 PM by Glenn Branched to a new discussion. RSS

Nest outside temperature not even close

Contributor

The outside temperature displayed on the web apps is not even close to:

1) my own digital outside thermometer

2) Accuweather for my location

3) the Weather Channel for my location

 

Today it was off by 6 - 10* all day.  If algorithms are based, in part, on this input....how accurate can it be?

 

Any fix in the works?

 

 

Edit:  This morning (2/1) they are all within 2*.  Maybe there was in issue with the feed yesterday?

  • Re: Nest outside temperature not even close
    Nest Employee

    Hi dznf0g,

     

    Nest gets outside weather info from Weather Underground based on the zip or postal code entered into your Nest.

     

    I’m betting that the temperature difference you’re seeing between the Nest app and the other sources your checking comes from the fact that Weather Underground’s weather reporting equipment is in a different location.

     

    Thanks,

    Calvin C.

  • Re: Nest outside temperature not even close
     woodgeek Guru

    I had noticed it being off a few times.  Then I noticed that the nest temp correlated with the Weather Underground station at the nearest airport ~5 miles away.

     

    Since a lot of WU stations are privately owned and poorly monitored, Nestlabs presumably only uses a subset of the stations that are well supported/calibrated.

    • Re: Nest outside temperature not even close
       Breezy_Point Contributor

      My station is used by Weather Underground and is also monitored by Citizen Weather Observer Program for accuracy. I calibrate the station once a month. It is very accurate. I think a lot of weather station owners are like me and very geeky about accuracy, but I can't say for sure. I think Weather Underground also monitors station accuracy but I am not sure. I have heard rumors that they dump you fast if unreliable or inaccurate, but just don't know. You can go the Weather Underground and see the type of station being used. I know for a fact that Davis weather stations are highly accurate and are almost professional level stations. I can't speak for any other type. They are very common stations in the Weather Underground network.

    • Re: Nest outside temperature not even close
       Breezy_Point Contributor

      Sorry, I thought I replied to this earlier. The history for KPADEVON2 can be found here:

       

      http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KPADEVON2


      This is accessed by clicking on the weather station name under the blue bar near the top of the page. When you get to this page there are all sorts of tabs for daily, weekly and monthly and if you scroll down far enough, you can see, and even download detailed readings. The level of detail varies. I like the yearly view and it could be useful if you want to create a history and map this to your HVAC run times. I am using average daily temperature for this purpose.


      On the right side of this page you can get information about the weather station, if it is a personal weather station. This includes type and if it has a MADIS id. If it has a MADIS id you can also do a web search on that id and get quality information on the station...for example, you can see this chart comparing the station to all other PWSs...


      http://weather.gladstonefamily.net/cgi-bin/wxqual.pl?site=C9381

       


      The almanac information on the first page comes from an automated weather reporting system, usually airports. When you view the nest web page, the background (snow, rain, etc.) comes from one of these pages as most personal weather stations are not capable of reporting this automatically.


      On the main page for the station, you can select Wundermap and see all of the stations in your area. Weather Underground includes every type of reporting station (AWOS, MADIS, RAWS, and personal weather stations). They are the only source of all this info at the same place that I know of and is why they are a good selection for this service.


      i hope this helps Nest users with Weather Underground. Let me know if there are more questions.

  • Re: Nest outside temperature not even close
    Contributor

    So...if you bogus your street address in the "control my nest" to make you appear closer to an accurate station, will that be the data reflected in my algorithms?  The one closest to me seems to be off from the 4 others pretty close to me.

  • Re: Nest outside temperature not even close
    New Nester

    I have also found the outside temperature has no relationship to the actual outside temperature. I always find the Weather Network to be very close. Today Nest is showing -21C while the actual temperature is -8C. My Postal  Code is correct, and the correct city is displayed by Nest. I live right beside a major airport, so I really don't understand how Weather Underground could be that far off. Last week we had a record breaking heat wave (+14C) which Weather Underground didn't see (reported something like -5C).  Nest energy summary provided the comment that my usage was below the weekly average because of user settings.

     

    I love the Nest thermostat, but the irrelevant weather data makes a lot of the key features like energy summary and early on, kind of pointless.

     

    I would be much happier if Nest used a weather service that was more realistic.

  • Re: Nest outside temperature not even close
    New Nester

    Just wanted to add my two cent's here.  I live in Mississauga, Ontario and I have found the outside temperature to be totally inaccurate.  But like -10 degrees!  No online weather site corroborates what Nest reports as my outside temperature, including Weather Underground.  Something is simply broken here.

     

    At the moment of this post my Nest claims it's -12 C outside while Weather Underground accurately reports it as about -3 C.  As do every other online weather source.

     

    Could someone at Nest please comment or look into this? Thanks!

  • Re: Nest outside temperature not even close
    New Nester

    Hi Farhad, I also live in Mississauga and was getting the same irrelevant readings as you.  I took Gotnospice's suggestion and changed my postal code to one in Brampton.  Worked like a charm.  Now the weather from Nest matches the outside temperature pretty much exactly.

    • Re: Nest outside temperature not even close
       Glenn New Nester

      What postal code did you use? I have tried a postal code near the airport and near our house.  The temperature always remains completely wrong - and it doesn't change when I change a postal code.  I have compared all the weather underground stations in the Mississauga and Etobicoke area and none of them match the 'outside temperature'

  • Re: Nest outside temperature not even close
     Breezy_Point Contributor

    I know a little about this. I have a calibrated weather station that sends data to both Weather Underground and CWOP (Citizens Weather Observer Program). I have been tracking local weather for over five years now and I can say the Weather Underground (Best Forecast) methodology is significantly more accurate than the NWS. Their forecast is usually accurate within one degree while the NWS is usually off by as much as 15 degrees. So the use of Weather Underground is a good one since, not only is their forecasting better, but their granularity is much higher. Unfortunately everyone experiences their own microclimate. In my case, Nest actually uses the information from my weather station for my area. An example of microclimate affects is that my station can report -30 (calibrated), and I can go .5 miles from my house and read a temp of -40. There is no substitute for a thermometer on your back deck! In lieu of that, Weather Underground probably has a reporting station closer to you than the NWS. I have been toying with idea of submitting a requirement to allow a user to select a weather station from Weather Underground that may more closely mimic your local microclimate but haven't done so yet.

  • Re: Nest outside temperature not even close
    Contributor

    Thanks, Breezy,

    I have additional observations to report.

    There are 14 stations listed for my zip; 4 airports and 8 amateur home based stations, and 2 that are the ones you see by bridges in the right of way of the highway (not sure who operates those)

     

    Nest has chosen to utilize one of the home based personal stations, which is OK as it is pretty close to me (2 miles).  My nest ALWAYS matches his temp.  I have noticed that whenever I see a significant difference in temp between my nest and my thermometer, all the "nearby weather stations" are missing from the list, leaving only the 4 airports.  I am then attached to an AP that is 15 miles away.

     

    How does nest choose...and what can be done by WU to remedy this "blackout" of data.  Yesterday I was attached to the AP for about 14 hours.

    • Re: Nest outside temperature not even close
       Breezy_Point Contributor

      I will tell you as much as I can, but it's mostly guessing based on observation. First of all there are several weather stations in my zip, so I don't know how Weather Underground chooses to display mine other than it is the nearest to one of the communities close to the center of my zip area.

      There is probably not much Weather Underground can do to remedy the situation when weather stations stop transmitting. When I first installed my weather station, I had some availability issues and I remedied it by getting a very low powered weather appliance (Meteohub) and putting it and all of my network gear on a battery backup system that will run for at least 8 hours. That only leaves the battery in my weather station itself that can run down. When that happened, Weather Undergrund substituted another station in my zip that was about ten miles away. I fixed that problem too, by setting up a low battery alert email in Meteohub. My station now has close to 100% reliability now.

       

      i am thinking of submitting an enhance request to allow users to select a weather station of their choices hat may more closely mimic their microclimate. In my area, there would be quite a few to choose from. What do you think?