Chongqing’s temperature swings from a 6.3°C (43.3°F) low to a 34.4°C (93.9°F) high across the year — a range of roughly 20.5°C. Spring (March–May) and autumn (September–November) are the two windows worth building a trip around. Summer is a furnace by national ranking, not just local complaint, and winter is a fog bank that can sit over the city for weeks. Both show up clearly in the numbers below, not just in traveller folklore.
If you’re pairing Chongqing with Chengdu on the standard Xi’an–Chengdu–Chongqing route, the same spring/autumn logic applies to both cities — build the whole loop around one of those two windows rather than picking dates city by city.
Month by month: temperature and humidity
| Season | Months | Temperature | Humidity |
|---|---|---|---|
| Spring | March–May | 15–26°C (59–79°F) | Climbing through the season |
| Summer | June–August | 30–33°C (86–91°F) average; July and August average ~33°C, with peak days over 40°C (104°F) | Year’s most oppressive combination — see below |
| Autumn | September–November | 16–29°C (61–84°F) | Peaks at 85% in October, the year’s highest monthly average |
| Winter | December–February | 6–8°C (43–46°F) average in Dec/Jan, the coldest months | Lower than summer but felt as a damp chill |
Checked 28 Aug 2026 Seasonal temperature ranges and the annual swing (6.3°C/43.3°F to 34.4°C/93.9°F) from climate-data.org, travelchinaguide.com and weather-and-climate.com.
Why Chongqing’s summer is worse than the numbers alone suggest
Chongqing ranks first — the hottest — on chinahighlights.com’s “Top 10 Furnace Cities” list, with August temperatures reaching Red Alert level, over 40°C (104°F). In 2011 the city logged 67 days at or above 35°C, a record for the 1980–2012 period. Chongqing was traditionally grouped with Wuhan and Nanjing as one of China’s “Three Furnaces.” A 2017 People’s Daily report revised the list to a top four — Chongqing, Fuzhou, Hangzhou, Nanchang — with Chongqing still leading.
Checked 28 Aug 2026 Furnace-city ranking and Red Alert threshold, plus the 67-day 2011 record, from chinahighlights.com and cucas.edu.cn. Revised four-city list from a 2017 People’s Daily report.
Humidity is what turns a hot month into an unbearable one. August averages around 74% humidity, and the annual average sits near 80%. Combined with 30–33°C air temperature, perceived heat routinely exceeds 40°C even on days the thermometer reads lower. There’s no shoulder-season trick within summer itself: July and August are the two months to avoid if you have any flexibility at all.
Checked 28 Aug 2026 Monthly humidity swing (74% in August, 85% in October, ~80% annual average) and the perceived-heat note from weather-and-climate.com.
Don’t schedule a first Chongqing trip for July or August. The heat and humidity aren’t a minor inconvenience you push through for cheaper flights — they’re the reason this city tops China’s own furnace rankings. If summer is your only window, prioritize air-conditioned indoor sights — the China Three Gorges Museum, for instance — over long stretches on open viewing platforms like Nanshan One Tree or Chaotianmen Square.
Winter fog: real, not a marketing nickname
Chongqing’s older nickname, “Fog City” (雾都), is not an exaggeration. Sources disagree on the exact yearly average: Britannica cites 120 foggy days a year; a separate figure sourced to notesfromchina.com and brivience.com puts it at 104. Neither source reconciles with the other. At the district level, Yunwu Mountain in Bishan District sees up to 204 foggy days a year.
Checked 28 Aug 2026 120 days/year from Britannica; 104 days/year from notesfromchina.com and brivience.com; 204-day district extreme (Yunwu Mountain, Bishan District) from chinahighlights.com.
The fog is heaviest in winter and spring, and it doesn’t behave like a morning mist that burns off by 10am — it can sit over the city for days or weeks at a stretch. That matters specifically if the reason you’re visiting is the skyline: Hongyadong’s tiered night lighting, the Nanshan One Tree viewing platform, and the Chaotianmen river-confluence view are all built around visibility. Winter isn’t uniformly bad — it’s a reasonable window for a hot-spring day trip specifically — but don’t build a first-time sightseeing itinerary around it.
Checked 28 Aug 2026 Fog persistence pattern (sustained atmospheric condition lasting weeks, heaviest winter/spring) from chinaxiantour.com-family sourcing.
The real best window
Spring (March–May) and autumn (September–November) are where every source checked lines up: chinahighlights.com, chinaxiantour.com and topchinatravel.com all name these as the recommended windows, citing mild temperatures, humidity well below the summer peak, and less fog than winter. Autumn adds better conditions for outdoor walking and photography generally. None of these sources recommends summer, and none flags winter as a good primary window — only as acceptable for hot springs specifically.
Checked 28 Aug 2026 Best-window consensus from chinahighlights.com, chinaxiantour.com and topchinatravel.com.
Within that, early-to-mid autumn — September, and October after the 7th, into November — is the stronger pick. Temperatures are similar to spring, but humidity is trending down from its October peak rather than climbing toward it, and fog risk is lower than in the winter months that follow.
One date to build around, not into: Golden Week
National Day Golden Week runs 1–7 October and is, nationally, one of the worst weeks of the year to travel in China — roughly 800 million domestic trips happen in this window, attractions are overcrowded, train tickets are near-impossible to get, and hotel rates spike. This lands squarely inside Chongqing’s best autumn window, which is exactly why it needs flagging on its own rather than getting folded into “autumn is good.” If you can’t avoid these dates, book trains and hotels well ahead, and put your must-see sights on the first or last day of the holiday — day one still has people in transit, and the final day sees many already heading home.
Checked 28 Aug 2026 800 million domestic trips figure and booking guidance from sinowander.com and roamchinatravel.com.
Shift a Golden Week trip by a week or two — late September, or mid-to-late October — and you get the same weather with a fraction of the crowds.
For what to actually do once you’ve picked dates, see the Chongqing hub. For how this fits the wider country picture, see best time to visit China.
Summarised from public traveller discussion, not from a visit. We have not travelled this route ourselves — see how we check.