Umbrellas are so much more trouble that they are not worth using. Unfortunately if you play rotational the sims you are not playing at the moment when it rains will automatically use umbrellas.
Vampires have issues with them as well (burning in between them closing and opening the umbrellas in the sun - separate bug report for that
When it rains a little (often times when it is about to clear but is still raining) the sims that use the umbrella when they walk will sometimes get in this strange movement of walking, stopping to close the umbrella, walking, stop to open the umbrella etc.
It takes forever to get anywhere when they do that and whatever they were supposed to walk to usually get reset in the end when they get closer anyway, so you have to stalk the sim doing this until they get to their destination to make sure they actually commit after that horrid walk.
When two sims are about to cloudgaze. This used to be an even bigger issue where it was simply impossible, now you might get it to work by selecting them to cloudgaze once, they go to the spot they will do it and you monitor. Usually one of them will open their umbrella just before the action to lay down so they will cancel that laying down action, but the other sims will still act like both are on the ground most of the time, or just reset.
Other times both "pick up" their umbrella between the action of going to the spot for cloudgazing and the action of laying down on the ground. So the action reset.
You will just have to continue selecting cloudgaze and pray they actually do just that.
Edit By crinrict: Added pack tag to title.
