Shanghai Weather in September: Temperatures, Rainfall, and What to Pack

Shanghai Weather in September

September marks the transition from Shanghai's sweltering summer into a more comfortable autumn. Daytime temperatures hover around 26–29°C, while nights cool to a pleasant 20–23°C. The humidity that defines July and August begins to retreat, making outdoor sightseeing far more bearable. Travelers during this month also catch the start of the osmanthus bloom and the pre-festival lantern displays lighting up the city. However, late-season typhoons can still push through, bringing sudden heavy rain. Packing smart layers and keeping a weather eye on tropical storm forecasts will let you make the most of this shoulder-season window.

Quick Shanghai Weather Facts for September

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Shanghai September Temperatures and Conditions

Shanghai Weather in September

September offers a marked improvement over the furnace months of July and August. Daytime highs typically range from 26–29°C, while nighttime lows settle between 20–23°C. The diurnal swing of about 6–8°C means you will feel a definite coolness in the evenings compared to midday. Early September can still produce feels-like temperatures of 31–33°C under lingering humidity, but by the final week, that drops to a more comfortable 26–28°C.

Humidity trends downward through the month, starting around 70–80% in week one and easing to 65–72% by late September. The sea surface temperature off Shanghai holds at roughly 24–26°C — warm enough for a dip if you find yourself near the coast. Sunshine averages about five hours per day, and the UV index remains moderate to high early in the month before settling lower in the final weeks. Each week typically brings roughly a 0.5°C cool-down, so the month closes noticeably cooler than it opens.

• Daytime highs: 26–29°C (79–84°F)
• Nighttime lows: 20–23°C (68–73°F)
• Feels-like temp: 31–33°C early month, 26–28°C late month
• Sea surface temp: ~24–26°C (75–79°F)
• Sunshine: ~5 hours per day average

See also our Shanghai Cbd Map guide.

Mid-Autumn Festival, Osmanthus Bloom, and September Events

Shanghai Weather in September

September hosts two of Shanghai's most evocative seasonal markers. The Mid-Autumn Festival (Zhongqiu Jie) celebrates the harvest moon on the 15th day of the 8th lunar month. In 2025, the festival falls on October 6, which means September visitors will catch pre-festival lantern displays and mooncake promotions rather than the main holiday. In 2026, the festival lands on September 25 — squarely within prime travel month. Mooncakes range from about $4–15 (¥28–100) per box at local bakeries to ¥200 or more for premium hotel gift boxes.

Meanwhile, the osmanthus bloom (Osmanthus fragrans) typically begins in the final week of September and peaks in early October. The sweet, apricot-like fragrance drifts through parks and narrow neighborhood lanes, turning a simple walk into a sensory experience. Shanghai Botanical Garden, Gucun Park, and Century Park all feature mature osmanthus trees, though the scent carries through residential areas with established plantings. The Shanghai Tourism Festival, running from mid-September through mid-October, brings discounted admission to major attractions across the city.

• Mid-Autumn Festival: 2025 falls Oct 6 (pre-festival lantern displays in September); 2026 falls Sep 25
• Osmanthus Bloom: Begins late September, peaks early October; visible at Shanghai Botanical Garden, Gucun Park, Century Park
• Shanghai Tourism Festival: Mid-September to mid-October; discounted attraction tickets citywide
• Yuyuan Lantern Display: Pre-festival installations begin in September; full lantern festival runs through Mid-Autumn

Rainfall, Typhoons, and Week-by-Week Changes

Shanghai Weather in September

Rainfall in September varies considerably depending on whether a tropical system grazes or makes landfall near Shanghai. Long-term records average around 146 mm for the month, though some monthly summaries cite closer to 90 mm. The difference often reflects whether a typhoon has passed through — for example, September 2024 delivered 282.51 mm, driven by storm activity. In years without direct typhoon hits, the rainfall total sits much lower. Travelers should expect 8–11 rain days, typically in the form of short tropical downpours or bands of rain rather than all-day drizzle.

Typhoon risk begins declining after its July–August peak, but late-season storms can still reach Shanghai. Historical examples include Typhoon Talim, which impacted the city in mid-September 2017, and Typhoon Fitow in early October 2013. The week-by-week progression below shows how conditions shift as the month advances.

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Early September

The first half of September still carries a summery feel. Average highs hover around 29°C, with lows near 23°C. Humidity remains stubbornly high at 75–80%, and any lingering August typhoons can still push moisture into the region. Rainfall tends to come in brief, intense bursts rather than prolonged spells. Daylight holds at roughly 12.5–13 hours, giving you plenty of time for sightseeing before sunset around 6:00 p.m.

Mid-September

Mid-September marks the pivot point of the month. A noticeable cool-down typically arrives around September 18–22, with average highs dropping to about 27°C and lows to 22°C. Humidity falls to 70–75%, and rain days become fewer. The comfortable conditions make this an excellent window for extended walks along the Bund or through former French Concession neighborhoods. In years when Mid-Autumn Festival falls in September, the city lights up with lantern displays and festive energy.

Late September

By the final week, Shanghai feels distinctly autumnal. Average highs sit around 25–26°C, with lows near 20°C. Humidity drops further to 65–72%, and the first mornings can feel genuinely cool. The osmanthus bloom usually begins in the last week, filling parks and residential lanes with a sweet, distinctive fragrance. Typhoon risk drops sharply but does not disappear entirely — late-season storms occasionally still make landfall. For most travelers, late September offers the ideal combination of warmth, lower humidity, and blooming flowers.

What to Wear and Pack for Shanghai in September

Shanghai Weather in September

September calls for a layering strategy that adapts to Shanghai's温差 (temperature differential) between sunny afternoons and air-conditioned interiors. Light, breathable fabrics work best for daytime, while a thin layer becomes essential once the sun drops. The humidity, though easing, still lingers early in the month, so moisture-wicking materials will keep you comfortable. A compact umbrella slips easily into a daypack for unexpected showers. Below is a practical packing guide for your September trip.

• Tops: T-shirts, light blouses, or short-sleeve shirts in breathable fabrics
• Bottoms: Long or cropped trousers, lightweight chinos, or modest-length skirts
• Outerwear: Thin cardigan or light jacket for evenings; one mid-weight layer (denim jacket or trench) for cool nights late in the month
• Rain and sun gear: Compact umbrella or foldable rain jacket; sunscreen SPF 30+; sunglasses
• Accessories: Light scarf for windy ferry rides or overly air-conditioned restaurants; comfortable walking shoes

Practical Tips for Visiting Shanghai in September

A few logistical considerations can smooth your September visit. Crowd levels remain moderate throughout the month, though Mid-Autumn Festival week draws larger domestic crowds to major sites. The Shanghai Tourism Festival running concurrent offers discounted tickets at many attractions — worth checking on Trip.com or Klook. Air-conditioned metro cars run cold even on warm days, so carry a thin layer for transit. Hotel prices stay moderate except during the Mid-Autumn week itself, when demand spikes.

Typhoon contingency planning is still relevant. Bookmark the China Meteorological Administration forecast and monitor it 3–5 days ahead of any outdoor-heavy itinerary. When storms threaten, indoor options like the Shanghai Museum, Long Museum, or Power Station of Art provide excellent alternatives. Finally, daylight shrinks from about 13 hours at the start of the month to roughly 11.5 hours by month-end — sunset shifts from around 6:00 p.m. to 5:40 p.m., so time your Bund evening walks accordingly.

• Maglev booking: The磁悬浮 train to Pudong Airport costs about $8 (¥50) one-way or $13 (¥80) round-trip on Trip.com
• Typhoon check: Monitor CMA forecasts 3–5 days ahead; have indoor backups ready
• Indoor alternatives: Shanghai Museum, Long Museum, Power Station of Art for stormy days
• Crowd timing: Mid-Autumn week brings peak domestic tourism; visit major sites early morning
• Sunset planning: Sun sets around 6:00 p.m. early month, 5:40 p.m. late month — ideal for evening Bund walks

Frequently Asked Questions

Q: How hot is Shanghai in September?

Daytime highs typically range from 26–29°C (79–84°F), while nighttime lows settle between 20–23°C (68–73°F). Early-month humidity can push feels-like temperatures to 31–33°C, but conditions cool noticeably by late September. It is warmer than October but significantly cooler than July and August.

Q: Does it rain a lot in Shanghai in September?

Rainfall totals range from about 90–150 mm depending on the year and source cited. You can expect 8–11 rain days, typically in short tropical downpours or typhoon-related bands rather than prolonged drizzle. Recent years show wide variation — September 2024 delivered over 280 mm, while quieter years see far less.

Q: Is September a good month to visit Shanghai?

Generally yes. Typhoon risk is declining from its July–August peak, summer humidity is easing, and outdoor sightseeing becomes comfortable. Along with May and October, September ranks among the best months to visit Shanghai for weather.

Q: What should I pack for Shanghai in September?

Pack light layers — T-shirts or blouses for daytime, a thin jacket or cardigan for evenings and air-conditioned venues. Bring long or cropped trousers, comfortable walking shoes, a compact umbrella, sunscreen, and a light scarf for ferry rides or overly cold restaurants. Leave heavy coats at home.

Q: When is typhoon season in Shanghai?

Typhoon risk runs from July through September, with the peak occurring in July and August. Late-season typhoons can still reach Shanghai in September — Typhoon Talim made landfall near the city in mid-September 2017. Check forecasts 3–5 days ahead during this period.

Q: When does osmanthus bloom in Shanghai?

The osmanthus bloom typically begins in the final week of September and reaches its peak in early October. The fragrance is strongest in late September. The Shanghai Botanical Garden, Gucun Park, Century Park, and mature residential lanes all offer excellent viewing opportunities.

Q: When is Mid-Autumn Festival in 2025 and 2026?

In 2025, Mid-Autumn Festival falls on October 6, so September visitors will see pre-festival lantern displays rather than the main holiday. In 2026, the festival falls on September 25, squarely within September travel dates.

Q: Is Shanghai humid in September?

Yes, especially early in the month. Humidity starts around 75–80% and declines to 65–72% by late September. Muggy conditions persist in the first week, but air noticeably dries out after September 20.