Well people existed for thousand of years without looking at a phone to determine the temperature. To live a free life you do not need to know the temperature down to tenths of a degree. Nor do you have to be supernatural, mere humans have been determining the weather for, again, thousands of years without a phone.
But yes you do have to be sensitive to the environment around you, you have to know a little bit about cloud formations, you have to understand the weather patterns in your area for the given time of the year, and you have to go outside periodically. None of which are particularly hard. But you do have to get out of the Silicon Valley bubble, and that is very hard for a lot of people.
Most of the time the forecast is just plain wrong (well unless you live in SF.) It is only right in SF because the forecast does not change much. We've ignore the forecast for decades because it was so wrong and by following it we were missing out on life. Try it, you might like not being a slave to a phone.