The meaning of a dream seeing a raincoat is to prepare for rain (bad weather). This is the obvious (manifest) meaning of this dream symbol. Dreaming of a raincoat means your unconscious mind wants to prepare you for the unexpected. This dream could have been triggered by a threat during the day. If you reflect and think about your waking reality, perhaps you can identify the context where a threat exists. The raincoat is only a metaphor. You can prepare to deal with the threat by using your resources and alternative plans.
Dreaming of erotic raincoat
There is at least one other meaning of a raincoat. It can be a metaphor for the latex that is used during intercourse.
#sbsadrawingaday prompt for August 22 2019 is raincoat
You know a parent is being over-protective when she prescribes a raincoat even when it isn’t raining. A mother instructed her child to wear his raincoat when she spotted a cleaner in the distance. Said cleaner was spraying water on the road, to wash away some mud. The mother didn’t want her child to be wet from the water spray. So raincoat it is.