Spring (March-May) and autumn (September-November) are the best times to visit Suzhou. In spring the gardens are at their most active — flowering trees, new growth on the bamboo, and the plum blossoms that feature in so much Chinese painting. Autumn brings cooler temperatures and the famous hairy crabs from Taihu Lake, which arrive in October and are a serious reason to time a trip. The chrysanthemum displays in the gardens are also at their best in October.
Summer is hot and humid, with temperatures regularly above 35°C and occasional flooding in July and August. The gardens are still beautiful, especially in early morning before the heat builds, but the heat makes extended outdoor exploration uncomfortable. The national holiday weeks — the week around October 1st (Golden Week) and Chinese New Year in January or February — bring enormous domestic tourism and should be avoided if possible. Gardens that are peaceful in October become genuinely packed during Golden Week.
Winter is cold but has its own charm. Fewer visitors, lower prices, and the gardens stripped back to their structural essentials. Snow in the gardens, when it happens, is particularly beautiful.