Shanghai in September
What to expect
In Shanghai, September sits in early autumn, a shoulder-season month where the feel can shift as the season turns. Most days feel warm without being relentless, and relatively steady temperatures through the day. Comfort is usually predictable, so a standard day plan works well. Daylight is moderate, so steady pacing works well.
September in context
How it compares to the rest of the year in Shanghai.
Monthly climate breakdown
Temperature
- Daytime high
-
- Nighttime low
-
- Feels like (avg)
-
Sunshine
- Daylight hours
- 12.4 h
- UV index (max)
- 8
- Typical sun hours
- 05:38 - 17:59
Rain & Snow
- Total rain
-
- Rainy days
- 14 days
- Cloud cover (avg)
- 58%
Humidity & Wind
- Humidity (avg)
- 80%
- Wind (avg)
-
- Wind (max gusts)
-
Daily climate explorer
Day 15 selected for September. Typical high 26.5°C and low 22.3°C.
Typical disruptions in September
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in September.
Muggy days Measures: Muggy days (dew point >=20C). Observed about 56% of days (16.7 days/month) in September. Historical risk signal only, not a day-by-day forecast.
16.7 days / month
~56% of days
Why this matters
- Expected days 16.7 days / month
- Probability ~56% of days
- Intensity Up to ~25°C (P95)
Muggy conditions are possible on ~17 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Hot feels-like days Measures: Hot feels-like days (>=32C). Observed about 31% of days (9.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
9.2 days / month
~31% of days
Why this matters
- Expected days 9.2 days / month
- Probability ~31% of days
- Intensity Up to ~39°C (P95)
Feels-like heat >=32C is possible on ~9 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Rain disruption Measures: Likely rain disruption days. Observed about 19% of days (5.7 days/month) in September. Historical risk signal only, not a day-by-day forecast.
5.7 days / month
~19% of days
Why this matters
- Expected days 5.7 days / month
- Probability ~19% of days
- Intensity Up to ~48mm (P95)
Rain disruption risk appears on ~6 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Washout risk Measures: Washout day risk. Observed about 18% of days (5.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
5.5 days / month
~18% of days
Why this matters
- Expected days 5.5 days / month
- Probability ~18% of days
- Intensity Up to ~50mm (P95)
Washout conditions are possible on ~6 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Very hot feels-like Measures: Very hot feels-like days (>=35C). Observed about 14% of days (4.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
4.2 days / month
~14% of days
Why this matters
- Expected days 4.2 days / month
- Probability ~14% of days
- Intensity Up to ~41°C (P95)
Very hot feels-like conditions are possible on ~4 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heavy rain days Measures: Heavy rain days (>=10mm). Observed about 11% of days (3.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
3.4 days / month
~11% of days
Why this matters
- Expected days 3.4 days / month
- Probability ~11% of days
- Intensity Up to ~57mm (P95)
Heavy rain is possible on ~3 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Show all disruptions (26 more)
Washout run Measures: Multi-day washout runs. Observed about 1.4 days/month in September. Historical risk signal only, not a day-by-day forecast.
1.4 days / month
Probability unavailable
Why this matters
- Expected days 1.4 days / month
- Probability —
- Intensity Up to ~44mm (P95)
Multi-day washout runs are possible on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Very heavy rain Measures: Very heavy rain days (>=25mm). Observed about 4% of days (1.1 days/month) in September. Historical risk signal only, not a day-by-day forecast.
1.1 days / month
~4% of days
Why this matters
- Expected days 1.1 days / month
- Probability ~4% of days
- Intensity Up to ~73mm (P95)
Very heavy rain is possible on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Stormy conditions Measures: Storm-impact proxy days. Observed about 3% of days (0.8 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.8 days / month
~3% of days
Why this matters
- Expected days 0.8 days / month
- Probability ~3% of days
- Intensity Up to ~98km/h (P95)
Stormy conditions are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Strong gusts Measures: Strong gust days (>=60 km/h). Observed about 2% of days (0.7 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.7 days / month
~2% of days
Why this matters
- Expected days 0.7 days / month
- Probability ~2% of days
- Intensity Up to ~98km/h (P95)
Strong gusts are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Extreme rain Measures: Extreme rain days (>=50mm). Observed about 1% of days (0.3 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.3 days / month
~1% of days
Why this matters
- Expected days 0.3 days / month
- Probability ~1% of days
- Intensity Up to ~84mm (P95)
Extreme rain is possible on ~0 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Severe gusts Measures: Severe gust days (>=80 km/h). Observed about 1% of days (0.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.2 days / month
~1% of days
Why this matters
- Expected days 0.2 days / month
- Probability ~1% of days
- Intensity Up to ~100km/h (P95)
Severe gusts are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Hot days Measures: Hot days (>=30C). Observed about 16% of days (4.8 days/month) in September. Historical risk signal only, not a day-by-day forecast.
4.8 days / month
~16% of days
Why this matters
- Expected days 4.8 days / month
- Probability ~16% of days
- Intensity Up to ~34°C (P95)
Hot days are possible on ~5 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat stress risk Measures: High heat stress days. Observed about 14% of days (4.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
4.2 days / month
~14% of days
Why this matters
- Expected days 4.2 days / month
- Probability ~14% of days
- Intensity Up to ~41°C (P95)
Heat stress is possible on ~4 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Oppressive humidity Measures: Oppressive humidity days (dew point >=24C). Observed about 13% of days (3.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
3.9 days / month
~13% of days
Why this matters
- Expected days 3.9 days / month
- Probability ~13% of days
- Intensity Up to ~26°C (P95)
Oppressive humidity is possible on ~4 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Feels-like heatwave Measures: Feels-like heatwave runs (>=3 days). Observed about 1.3 days/month in September. Historical risk signal only, not a day-by-day forecast.
1.3 days / month
Probability unavailable
Why this matters
- Expected days 1.3 days / month
- Probability —
- Intensity Up to ~38°C (P95)
Feels-like heatwave runs are possible on ~1 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Fog-likely signal Measures: Fog-likely visibility proxy. Observed about 4% of days (1.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
1.2 days / month
~4% of days
Why this matters
- Expected days 1.2 days / month
- Probability ~4% of days
- Intensity Up to ~95% (P95)
Fog-likely conditions are possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Humid days Measures: Humid days (dew point >=18C). Observed about 76% of days (22.7 days/month) in September. Historical risk signal only, not a day-by-day forecast.
22.7 days / month
~76% of days
Why this matters
- Expected days 22.7 days / month
- Probability ~76% of days
- Intensity Up to ~25°C (P95)
Humid conditions are possible on ~23 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
High humidity Measures: High humidity days (RH >=80%). Observed about 59% of days (17.6 days/month) in September. Historical risk signal only, not a day-by-day forecast.
17.6 days / month
~59% of days
Why this matters
- Expected days 17.6 days / month
- Probability ~59% of days
- Intensity Up to ~91% (P95)
High humidity is possible on ~18 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Wet days Measures: Wet days (>=0.1mm). Observed about 58% of days (17.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
17.4 days / month
~58% of days
Why this matters
- Expected days 17.4 days / month
- Probability ~58% of days
- Intensity Up to ~28mm (P95)
Measurable rain is possible on ~17 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cloudy days Measures: Cloudy days (cloud cover >=60%). Observed about 51% of days (15.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
15.2 days / month
~51% of days
Why this matters
- Expected days 15.2 days / month
- Probability ~51% of days
- Intensity Up to ~100% (P95)
Cloudy skies are possible on ~15 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rainy hours Measures: Rain-hours signal (>=3h rain). Observed about 47% of days (14.0 days/month) in September. Historical risk signal only, not a day-by-day forecast.
14.0 days / month
~47% of days
Why this matters
- Expected days 14.0 days / month
- Probability ~47% of days
- Intensity Up to ~22h (P95)
Several rainy hours are possible on ~14 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Warm nights Measures: Warm nights (min >=22C). Observed about 44% of days (13.3 days/month) in September. Historical risk signal only, not a day-by-day forecast.
13.3 days / month
~44% of days
Why this matters
- Expected days 13.3 days / month
- Probability ~44% of days
- Intensity Up to ~26°C (P95)
Warm nights are possible on ~13 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Wet most of day Measures: Wet-most-of-day signal (>=6h rain). Observed about 33% of days (9.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
9.9 days / month
~33% of days
Why this matters
- Expected days 9.9 days / month
- Probability ~33% of days
- Intensity Up to ~23h (P95)
Wet-most-of-day conditions are possible on ~10 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Mostly cloudy days Measures: Mostly cloudy days (cloud cover >=80%). Observed about 29% of days (8.7 days/month) in September. Historical risk signal only, not a day-by-day forecast.
8.7 days / month
~29% of days
Why this matters
- Expected days 8.7 days / month
- Probability ~29% of days
- Intensity Up to ~100% (P95)
Mostly cloudy skies are possible on ~9 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Gusty days Measures: Gusty days (>=40 km/h). Observed about 25% of days (7.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
7.5 days / month
~25% of days
Why this matters
- Expected days 7.5 days / month
- Probability ~25% of days
- Intensity Up to ~72km/h (P95)
Gusty conditions are possible on ~7 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Convective risk Measures: Convective storm risk proxy. Observed about 18% of days (5.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
5.5 days / month
~18% of days
Why this matters
- Expected days 5.5 days / month
- Probability ~18% of days
- Intensity Up to ~25°C (P95)
Convective risk signal appears on ~5 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Overcast days Measures: Overcast days (cloud cover >=95%). Observed about 13% of days (3.8 days/month) in September. Historical risk signal only, not a day-by-day forecast.
3.8 days / month
~13% of days
Why this matters
- Expected days 3.8 days / month
- Probability ~13% of days
- Intensity Up to ~100% (P95)
Overcast skies are possible on ~4 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Hot nights Measures: Hot nights (min >=25C). Observed about 11% of days (3.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
3.2 days / month
~11% of days
Why this matters
- Expected days 3.2 days / month
- Probability ~11% of days
- Intensity Up to ~27°C (P95)
Hot nights are possible on ~3 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data Measures: Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data. Observed about 4% of days (1.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
1.2 days / month
~4% of days
Why this matters
- Expected days 1.2 days / month
- Probability ~4% of days
- Intensity Up to ~95 (P95)
Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data is possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Breezy days Measures: Breezy days (mean wind >=25 km/h). Observed about 3% of days (0.8 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.8 days / month
~3% of days
Why this matters
- Expected days 0.8 days / month
- Probability ~3% of days
- Intensity Up to ~36km/h (P95)
Breezy conditions are possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Heatwave run Measures: Heatwave runs (>=3 hot days). Observed about 0.6 days/month in September. Historical risk signal only, not a day-by-day forecast.
0.6 days / month
Probability unavailable
Why this matters
- Expected days 0.6 days / month
- Probability —
- Intensity Up to ~33°C (P95)
Heatwave runs are possible on ~1 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Frequently asked questions
Is September a good time to visit Shanghai?
Typical September days in Shanghai reach highs of 27°C (81°F) with nights around 22°C (72°F). It usually feels hot by day and mild after dark. Overall, September sits in the middle of the Shanghai climate range.
What are temperatures like in September?
In September, you can usually expect highs of 27°C (81°F) and lows near 22°C (72°F). That means hot days and mild nights, so pack layers you can add or remove.
How much does it rain in September?
Rainfall in September averages 115 mm (4.5 in) across roughly 14 days. Overall it is a very wet time of year, so a light rain jacket and waterproof shoes are very handy.
How many hours of daylight are there in September?
You can expect about 12 hours of daylight in September. Sunrise is typically around 05:38 and sunset near 17:59. Daylight is fairly typical, with enough time for sightseeing.
How strong is the sun in September?
UV levels are often high (around 8). Regular sunscreen and a hat are recommended.
Is it windy in September?
In September, average wind speeds are around 13 km/h (8 mph), with gusts on the windiest days reaching about 48 km/h (30 mph). On the ground, it is it often feels breezy, especially in more exposed spots or along the coast.