Add a new weather platform, type darksky:
weather:
- platform: darksky
api_key: !secret darksky_key
mode: daily
latitude: !secret latitude
longitude: !secret longitude
You’ll need to create a DarkSky account.
I made a PR to fix the issue with the met integration, the one that is configured by default, using the elevation in feet as meters. This should fix the issue, but YMMV with accuracy still.
I’m seeing wildly wrong temps as well with default met.no integration. Now that Darksky is dead that’s not really a valid fix anymore. Looking at the other responses here i’m really wondering if this isn’t an elevation issue (im in abq). I don’t think its met.no itself because if I look the temps on yr.no which is also backed by met.no and they are much more accurate.
I figured out what happened. See here. It is an elevation issue that was fixed but then a different change made it incorrect again.
Wow. Tracing back the issues - this is quite a web of going back and forth. It seems there has been no central decisions on managing these settings. Leave it to America to threw a wrench into everything! 
Ha tell me about it, this is the 2nd imperial bug I’ve hit in the last couple of days. Its almost like most people don’t use freedom units.
Just put ºC as unit_of_measurement in the customize section for the temperature that has the wrong value. Home assistant will see that it has ºC as units and convert it to your system units (ºF).
Does this work for forecasts in a weather platform like the default met integration upon onboarding?
Even if it does work, the forecast isn’t in Celsius, the elevation is incorrect, which is used in the met integration. This can cause the temperature to be off by so much as to appear to be in Celsius.
I’m sure that may be the case now but the original thread issue just had bad units based on the picture comparing darksky to the built in
22.6 * 9/5 + 32 = 72.68 ~ 73
The weather platforms automatically convert temperature. I have inside information that the original poster fixed the elevation and it fixed the problem 
Ah yes, so that means he was lying here then?
No, it means it was fixed and I didn’t see or notice it because I was using DarkSky (and not seeing HA’s weather). It was broken, and still “slightly” broken (e.g. on the UI showing meters instead of feet).
I think this was uncalled for. We shouldn’t accuse others of lying. Or you were being sarcastic to stick it to me. Either way, it isn’t a very welcoming environment.
right back at ya 
We’re all getting confused here.
F to C was not fixed by the elevation change. The elevation change fixed the drastically incorrect HA weather forecast: Why is HA's Weather widget so far off?
I don’t know what fixed the degrees showing in Celsius even though Imperial was set. Probably something in the backend that “fixed” it. There’s been several HA updates since my original post.
The elevation change fixed the drastically incorrect temperature values.
My position is that the fact that it showed something that appeared to be in Celsius was caused by the elevation issue. 6000 meters vs 6000 ft makes a huge difference in the weather for met forecast. It just happened that it caused it to be off by the exact difference of converting to Celsius.
I don’t think you will see this difference if you are near sea level for example. Try getting your weather for New York City for example
Yes I understand that but @MatthewFlamm doesn’t. Which is why I was explaining to the @ExMachina that he can simply set the unit_of_measure as a temp fix to the ORIGINAL issue in the thread. Which would have fixed your issue way back when because units weren’t set properly (which was a bug).
This whole elevation thing is 100% a separate issue that was raised in this dead thread.
EDIT: Also, you should note that not everyone is responding to you. The thread owner (You) gets notifications when anyone replies in a thread. It makes it confusing unless you know this. So many people aren’t responding to you but you keep getting notifications that they are. The system is kind of backwards in that regards. You can change the settings on the thread to alleviate this issue.
The original post, you can see the elevation is set at 6200 meters. I will stick to my facts rather than making personal attacks on who understands or doesn’t understand.
My guy, you started this whole debacle. You reap what you sew.