Hi Nancy,
A question that I would be curious about would be if there are any sensory issues for the individual. How is their sense of hot and cold, when they were young were they the type of kid who always wanted short or long sleeves, do they find certain types of fabric or fit uncomfortable?
I don’t know if the person has an i-pad or i-phone but there are a few apps that might be useful (iDress for example) there’s also a thermometer which shows the appropriate clothing for the temperature (http://www.lucasworks.org/teaching-temperature.html#dials). I haven’t used product myself but it looks like something that could be helpful to somebody who’s not quite sure of what to wear.
If the person is somebody who can check the weather on their own, then a posted guide of what to wear based on the temperature might be something simple that could be helpful.
good luck and best wishes,
Cate