Whether the weather is good, or bad?

🚧 Developers
1

Hi

Shown below is the temperature readings I am getting from 3 different sources for the same location!

image

The 1st 2 are community devices, the 3rd is the built-in device. They are @bangali's ApiXU Weather Driver V2.0.0, @Cobra's Custom WU Driver V2.5.0 and the built-in Weather Underground respectively.

What gives the huge discrepancies for temperature? Anybody got some insight into this?

Thanks
J

2

There is an old saying...... "A man with one thermometer knows what temperature it is, a man with two thermometers does not know what the temperature is"

Seriously my Wunderground site is about 3 miles away from me and the temperature is between 2.5 and 3 °C higher. I would think this is normal. However I would think the 36 °C (I'm assuming your in °C) is in the sun or has some other issue.

Do you have an old fashion liquid thermometer (used to be mercury)? I find them to always be in the "ball park" and useful for a sanity check.

John

3

The one that is the closest to correct is the 36C one (@Cobra's Custom WU Driver)

None of the readings are from my personal Netatmo WS. I'm working on the integration, but based on my Netatmo, 36C is about right, as it reads 35C.

The ODD things is the Custom WU driver the built-ion driver all pull from the same source... They use the same postal code, the same api key!!

J

1 Like
4

for apixu also check with lat/long and city. sometimes that picks up a closer weather station than using zip code.

5

Obviously, my code is better than everyone else's. :slight_smile:
Lol.

Andy

3 Likes
6

thanks for the good laugh :smile:

1 Like
7

One of my drivers uses either apixu or wu and I find wu most accurate.
Probably because there is possibly a station nearer to me.
Now I just use my own pws and (after some adjustment) I know it’s correct.

Probably nothing to do with code at all :slight_smile:

Andy

8

Actually I would be interested to use a station id in the wu settings instead of a location.
Both in mine and the built-in driver
That way you would guarantee that they are using the same data

Andy

9

Interesting...
I just did the comparison
Temp is 0.5 degrees C lower with the built-in driver (could just be rounding)
But... humidity is way off (about 5%)

I know the station is correct because it’s mine (realised I’m still pushing data to wu. But will probably continue until they cut off access)

Andy

10

It might be worth checking the Wunderground location temperature in you web browser to see if it is the same as on you display. Just a simple sanity test.

If different look at other sites in your area, just to get a feel of the site to site variation.

John

11

Why not do this? while the built in driver says "Zip Code (optional)" you can actually put anything that WeatherUnderground is used to seeing:

https://serbian.wunderground.com/weather/api/d/docs?d=data/index

ie:

image
image807×680 47.6 KB

12

The truth is, you are looking at three uncalibrated thermometers, or one calibrated, and two uncalibrated thermometers. Three sources at the same location would be three weather stations right next to one another. I'm sure that's not what you're looking at. Remember, weather is local, so if you don't have your own calibrated station, you need to accept an average that seems correct based on a large enough sample size.

This is a very good point @JohnRob makes. If you don't have the expensive equipment and a controlled environment of calibrate your own thermometer (and how many would really) then looking at temperatures from various weather stations in close range of each other on WU is your best bet to find an average that you can live with and follow that one. :smiley:

1 Like
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