You can’t solve it, it’s always the temperature at the start of the activitity from some near weather station. But you could connect some third party apps that writes weather data into the activity description, these are often more useful then the Strava weather.

So this information is almost useless, because the initial temperature doesn't tell me anything about my activities. And to fix this I have to pay for a third-party app.

The weather information is an advantage for those who have a subscription, but it doesn't fulfill its function!!? So what's the advantage? The developers could just include the information about the end of the workout… I love Strava, but I’m thinking about not renew my subscription… I really don't know if it's useful to keep paying.

Is it always only the start temperature though? I’ve noticed that some Strava users are using the “temperature” kind of map - and it does show the temp change during the activity (similar as with HR, elevation, power or any other “colour coded” map). However, I never made it work myself - I’m a subscriber but perhaps my location or device isn't supported, hard to tell… but it seems it's possible to make it work. 

​@Jan_Mantau ok I've found the article mentioning it - I was even asking in the comments how to make it work but unfortunately got no answer:

That’s because you need a temperature sensor for that to work but runners usually don’t have those or when they have, it’s embedded in the sports watch and measures the wrist temperature only. For riders a temperature sensor is fairly normal these days and you get the temperature graph and if you want to a temperature map too.

Maybe some people who live in very constant climate see a use in it or you could argue that weather at the start is better as no weather at all. But you are right that the start weather is often enough very misleading, especially for longer activities or those with high elevations changes. I complained about that many iterations of Strava forums before (in 2018 or so) but to no avail.

Ok that makes sense - in terms of explanation for why it's not working now. However - if Strava can use the start time temperature from the location weather data (without the device’s actual sensor), it shouldn't be that much of a problem to do the same in time intervals - say, a data point for each ~15 mins or so. That would make the weather information more accurate - and the temperature map would be doable too then

I would be very happy if they improved this... today I started my training at 26ºC and finished at 29ºC, but the information in my training is 24ºC, it seems like a joke...

In Brazil, the temperature variation is very large. Today I started the activity with 25 degrees Celsius and ended with 39 measured by the Igpsport BSC200. Strava says the activity was 24 degrees Celsius.