Dreams and visions in which autumn occurs tells you about stagnation, turning in, retreat and quiet period. Take time to mature your dreams and wishes. The decay of the cycle of life, the decay, death and rebirth, the end and the new beginning.
Protection and support. Another explanation is that you have to dig a little deeper, investigate and take time to give a place to things and situation and / or to properly assess them.
A spiritual explanation is connecting with the hereafter, guides, helpers and supporters. Halloween, Veil between all dimensions, All Saints and All Souls. Another explanation is survival, getting ready for the new and attracting silence time.