I am not sure that having pop-ups due to weather is directly related to the Internet of Things... But it is a neat idea, and something you can already do with IFTTT (If This Then That):
https://ifttt.com/connect/weather/sms.
Now it would be neat if you had an umbrella rack that, when rain was expected that day, rotated an umbrella into place next to the door handle so it would be harder to forget it
Or had something on your car which detected rain drops and rolled up the windows. Or when rain started at home, had a speaker which called the cat/dog in and unlocked a pet door for her.