Solved

Weird weather

Of course, I am not an expert, but in my opinion in less than 5 minutes the temperature has changed (today in the race) from 21 ° C to 14 ° C, and as for me it is a bit wrong, and this is at the same time that there were no clouds, no I understand that it is already evening, but in 5 minutes - 7 ° C somehow a lot, and I would like to know why it happens so abruptly. 
P. S. Sorry for my English. 

Thanks.

If Openweather is losing 7c in 5 minutes there is something seriously wrong with their service, although, have never seen this. I have however, seen heavy rain in a race where the app shows clear skies with cold temperatures .

I think the second part could be because the game uses exact coordinates of the circuit, while the weather app only lets us specify the cities by name (I might be wrong about this).

I noticed this about a month ago while racing in Spain. Like a layman I gave in Barcelona as a location to the app (because the branding of the actual GP), and the weather app reported as sunny and dry. iGP was reporting heavy rain however, so a little bit of digging and I realised the circuit is located in Montmelo which infact had heavy rain at the time.

I always try to put the actual circuit into the app, but as you say not always possible for all.  For Canada you can set Circuit Gilles Villeneuve as a location it just seems the actual race conditions never seem to match the app ?‍♂️