The worst months to visit Chengdu are July and August. During these mid-summer months, the city experiences intense humidity and peak temperatures that frequently exceed 35°C (95°F). This period also coincides with the region's heaviest rainfall, which can disrupt outdoor plans. Furthermore, because of school summer holidays, major attractions like the Chengdu Panda Base are exceptionally crowded, and the giant pandas themselves often stay indoors in air-conditioned rooms to escape the heat.
If you dislike damp, biting cold, you may also want to avoid January. While temperatures rarely drop far below freezing, Chengdu's high humidity and persistent winter fog make the cold feel much more intense. Additionally, winter is the season when the Sichuan Basin is most prone to overcast skies and occasional smog.
Finally, try to avoid the first week of October (Golden Week) and the Chinese New Year period (usually in late January or February). During these national holidays, domestic tourism surges dramatically, leading to heavily congested transit, packed sightseeing spots, and significantly higher hotel rates.