The journalist is making a product for the reader in the best case, their job is to help the reader. The second example you mention is a typical example of clickbait journalism, where the journalist has betrayed the reader and is trying to steal their attention, because they actually serve advertisers.

But the first example is not very useful either. That journalist could be replaced by a fully automated thermometer. Or weather stations with an API. Context is useful: “It is 35 degrees Celsius, and we’re predicting that it will stay sunny all day” will help you plan your day. “It is 35 degrees Celsius today, finishing off an unseasonably warm September” could provide a little info about the overall trend in the weather this year.

I don’t see any particular reason that journalists should follow your definition, which you seem to have just… made up?

I think you might need a chill pill, I've never met a single journalist or editor who would let "you won't believe how hot it is" pass in more than a tweet.

You're describing a microphone / voice recorder, not a journalist.

There are of course places you can go to get raw weather data, but a journalist might put it in context of what else is going on, interview farmers or climatologists about the situation, etc.

There are lots of kinds of journalism, but maybe most important is investigative journalism. They are literally doing an investigation - reading source material, actively seeking out the right people to interview and asking them right questions, following the leads to more information.