I didn’t read the first version of your poem, so it was only after reading Nedra’s suggestions that I learned that the subject is/was a woman and that the light rain described tears. This didn’t occur to me when I read the poem. Perhaps a comma after autumn would place more emphasis on the light rain belonging with the smile and not describing the autumn.
I may be way off here, so please ignore all the above if the poem says exactly what you need to express!
Helen