The cool season is a good time to plant bamboo.

When temperatures get too high an unestablished transplant may be unable to take up enough water and survive. A spring transplant may not have enough time to become established enough to endure summer heat, so autumn may be a good time.
I've seen good success transplanting in January of an unusually mild winter, breaking through a thin layer of frozen soil to do so.
Unlike the spring transplants, all such plants survived the drought the following summer.
However where winters tend to see sustained freezing temperatures with winds, an early spring transplant may be the best available option as the icy winds of winter would otherwise cause more damage to the bamboo than the summer heat.
At times the soil may be undesirably soggy, but you can plan ahead and create a raised mound to help drain excess soil moisture before planting your bamboo.