Avg High
Osaka in September
Avg Low
Rain
Daylight
12h
What to expect
Osaka is in early autumn during September, a shoulder-season stretch where conditions can nudge warmer or cooler week to week. Afternoons often feel hot in direct sun, and a gentle drop-off once the sun goes down. Conditions tend to feel steady, which makes planning simple. You get a comfortable daylight window for day trips and sightseeing.
September in context
How it compares to the rest of the year in Osaka.
Hottest (avg)
#3 / 12
Wettest (avg)
#3 / 12
Daylight Hours
#6 / 12
Windiest (avg)
#7 / 12
Highest UV
#6 / 12
Most Humid
#4 / 12
Monthly climate breakdown
Temperature
- Daytime high
-
- Nighttime low
-
- Feels like (avg)
-
Sunshine
- Daylight hours
- 12.4 h
- UV index (max)
- 7
- Typical sun hours
- 05:40 - 18:04
Rain & Snow
- Total rain
-
- Rainy days
- 15 days
- Cloud cover (avg)
- 61%
Humidity & Wind
- Humidity (avg)
- 76%
- Wind (avg)
-
- Wind (max gusts)
-
Daily climate explorer
Day 15 selected for September. Typical high 27.9°C and low 20.9°C.
Typical disruptions in September
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in September.
Humidity High impact
Muggy days Measures: Muggy days (dew point >=20C). Observed about 46% of days (13.8 days/month) in September. Historical risk signal only, not a day-by-day forecast.
13.8 days / month
~46% of days
Why this matters
- Expected days 13.8 days / month
- Probability ~46% of days
- Intensity Up to ~24°C (P95)
Muggy conditions are possible on ~14 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Heat High impact
Hot feels-like days Measures: Hot feels-like days (>=32C). Observed about 39% of days (11.8 days/month) in September. Historical risk signal only, not a day-by-day forecast.
11.8 days / month
~39% of days
Why this matters
- Expected days 11.8 days / month
- Probability ~39% of days
- Intensity Up to ~38°C (P95)
Feels-like heat >=32C is possible on ~12 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat High impact
Hot days Measures: Hot days (>=30C). Observed about 29% of days (8.6 days/month) in September. Historical risk signal only, not a day-by-day forecast.
8.6 days / month
~29% of days
Why this matters
- Expected days 8.6 days / month
- Probability ~29% of days
- Intensity Up to ~34°C (P95)
Hot days are possible on ~9 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Rain High impact
Rain disruption Measures: Likely rain disruption days. Observed about 24% of days (7.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
7.2 days / month
~24% of days
Why this matters
- Expected days 7.2 days / month
- Probability ~24% of days
- Intensity Up to ~60mm (P95)
Rain disruption risk appears on ~7 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain High impact
Washout risk Measures: Washout day risk. Observed about 23% of days (6.8 days/month) in September. Historical risk signal only, not a day-by-day forecast.
6.8 days / month
~23% of days
Why this matters
- Expected days 6.8 days / month
- Probability ~23% of days
- Intensity Up to ~61mm (P95)
Washout conditions are possible on ~7 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain High impact
Heavy rain days Measures: Heavy rain days (>=10mm). Observed about 16% of days (4.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
4.9 days / month
~16% of days
Why this matters
- Expected days 4.9 days / month
- Probability ~16% of days
- Intensity Up to ~65mm (P95)
Heavy rain is possible on ~5 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Show all disruptions (27 more)
Heat High impact
Very hot feels-like Measures: Very hot feels-like days (>=35C). Observed about 15% of days (4.6 days/month) in September. Historical risk signal only, not a day-by-day forecast.
4.6 days / month
~15% of days
Why this matters
- Expected days 4.6 days / month
- Probability ~15% of days
- Intensity Up to ~40°C (P95)
Very hot feels-like conditions are possible on ~5 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Rain High impact
Very heavy rain Measures: Very heavy rain days (>=25mm). Observed about 7% of days (2.0 days/month) in September. Historical risk signal only, not a day-by-day forecast.
2.0 days / month
~7% of days
Why this matters
- Expected days 2.0 days / month
- Probability ~7% of days
- Intensity Up to ~79mm (P95)
Very heavy rain is possible on ~2 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Rain High impact
Washout run Measures: Multi-day washout runs. Observed about 1.8 days/month in September. Historical risk signal only, not a day-by-day forecast.
1.8 days / month
Probability unavailable
Why this matters
- Expected days 1.8 days / month
- Probability —
- Intensity Up to ~60mm (P95)
Multi-day washout runs are possible on ~2 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Wind High impact
Stormy conditions Measures: Storm-impact proxy days. Observed about 5% of days (1.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
1.5 days / month
~5% of days
Why this matters
- Expected days 1.5 days / month
- Probability ~5% of days
- Intensity Up to ~107km/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.
Wind High impact
Strong gusts Measures: Strong gust days (>=60 km/h). Observed about 5% of days (1.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
1.4 days / month
~5% of days
Why this matters
- Expected days 1.4 days / month
- Probability ~5% of days
- Intensity Up to ~108km/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.
Rain High impact
Extreme rain Measures: Extreme rain days (>=50mm). Observed about 2% of days (0.6 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.6 days / month
~2% of days
Why this matters
- Expected days 0.6 days / month
- Probability ~2% of days
- Intensity Up to ~90mm (P95)
Extreme rain is possible on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Wind High impact
Severe gusts Measures: Severe gust days (>=80 km/h). Observed about 2% of days (0.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.5 days / month
~2% of days
Why this matters
- Expected days 0.5 days / month
- Probability ~2% of days
- Intensity Up to ~134km/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.
Heat Moderate
Heat stress risk Measures: High heat stress days. Observed about 15% of days (4.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
4.5 days / month
~15% of days
Why this matters
- Expected days 4.5 days / month
- Probability ~15% of days
- Intensity Up to ~40°C (P95)
Heat stress is possible on ~5 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Heat Moderate
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.
Heat Moderate
Heatwave run Measures: Heatwave runs (>=3 hot days). Observed about 1.1 days/month in September. Historical risk signal only, not a day-by-day forecast.
1.1 days / month
Probability unavailable
Why this matters
- Expected days 1.1 days / month
- Probability —
- Intensity Up to ~35°C (P95)
Heatwave runs are possible on ~1 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Humidity Minor
Humid days Measures: Humid days (dew point >=18C). Observed about 70% of days (20.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
20.9 days / month
~70% of days
Why this matters
- Expected days 20.9 days / month
- Probability ~70% of days
- Intensity Up to ~24°C (P95)
Humid conditions are possible on ~21 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Rain Minor
Wet days Measures: Wet days (>=0.1mm). Observed about 60% of days (17.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
17.9 days / month
~60% of days
Why this matters
- Expected days 17.9 days / month
- Probability ~60% of days
- Intensity Up to ~44mm (P95)
Measurable rain is possible on ~18 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cloud Minor
Cloudy days Measures: Cloudy days (cloud cover >=60%). Observed about 54% of days (16.2 days/month) in September. Historical risk signal only, not a day-by-day forecast.
16.2 days / month
~54% of days
Why this matters
- Expected days 16.2 days / month
- Probability ~54% of days
- Intensity Up to ~100% (P95)
Cloudy skies are possible on ~16 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rain Minor
Rainy hours Measures: Rain-hours signal (>=3h rain). Observed about 46% of days (13.8 days/month) in September. Historical risk signal only, not a day-by-day forecast.
13.8 days / month
~46% of days
Why this matters
- Expected days 13.8 days / month
- Probability ~46% of days
- Intensity Up to ~21h (P95)
Several rainy hours are possible on ~14 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Heat Minor
Warm nights Measures: Warm nights (min >=22C). Observed about 40% of days (11.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
11.9 days / month
~40% of days
Why this matters
- Expected days 11.9 days / month
- Probability ~40% of days
- Intensity Up to ~26°C (P95)
Warm nights are possible on ~12 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cloud Minor
Mostly cloudy days Measures: Mostly cloudy days (cloud cover >=80%). Observed about 34% of days (10.1 days/month) in September. Historical risk signal only, not a day-by-day forecast.
10.1 days / month
~34% of days
Why this matters
- Expected days 10.1 days / month
- Probability ~34% of days
- Intensity Up to ~100% (P95)
Mostly cloudy skies are possible on ~10 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rain Minor
Wet most of day Measures: Wet-most-of-day signal (>=6h rain). Observed about 33% of days (10.0 days/month) in September. Historical risk signal only, not a day-by-day forecast.
10.0 days / month
~33% of days
Why this matters
- Expected days 10.0 days / month
- Probability ~33% of days
- Intensity Up to ~22h (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.
Humidity Minor
High humidity Measures: High humidity days (RH >=80%). Observed about 32% of days (9.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
9.5 days / month
~32% of days
Why this matters
- Expected days 9.5 days / month
- Probability ~32% of days
- Intensity Up to ~90% (P95)
High humidity is possible on ~9 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Wind Minor
Gusty days Measures: Gusty days (>=40 km/h). Observed about 23% of days (6.8 days/month) in September. Historical risk signal only, not a day-by-day forecast.
6.8 days / month
~23% of days
Why this matters
- Expected days 6.8 days / month
- Probability ~23% of days
- Intensity Up to ~87km/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.
Humidity Minor
Convective risk Measures: Convective storm risk proxy. Observed about 20% of days (5.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
5.9 days / month
~20% of days
Why this matters
- Expected days 5.9 days / month
- Probability ~20% of days
- Intensity Up to ~24°C (P95)
Convective risk signal appears on ~6 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cloud Minor
Overcast days Measures: Overcast days (cloud cover >=95%). Observed about 17% of days (5.1 days/month) in September. Historical risk signal only, not a day-by-day forecast.
5.1 days / month
~17% of days
Why this matters
- Expected days 5.1 days / month
- Probability ~17% of days
- Intensity Up to ~100% (P95)
Overcast skies are possible on ~5 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Heat Minor
Hot nights Measures: Hot nights (min >=25C). Observed about 6% of days (1.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
1.9 days / month
~6% of days
Why this matters
- Expected days 1.9 days / month
- Probability ~6% of days
- Intensity Up to ~28°C (P95)
Hot nights are possible on ~2 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Humidity Minor
Oppressive humidity Measures: Oppressive humidity days (dew point >=24C). Observed about 3% of days (0.9 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.9 days / month
~3% of days
Why this matters
- Expected days 0.9 days / month
- Probability ~3% of days
- Intensity Up to ~25°C (P95)
Oppressive humidity is possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Visibility Minor
Fog-likely signal Measures: Fog-likely visibility proxy. Observed about 2% of days (0.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.5 days / month
~2% of days
Why this matters
- Expected days 0.5 days / month
- Probability ~2% of days
- Intensity Up to ~94% (P95)
Fog-likely conditions are possible on ~1 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Other Minor
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 2% of days (0.5 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.5 days / month
~2% of days
Why this matters
- Expected days 0.5 days / month
- Probability ~2% of days
- Intensity Up to ~94 (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.
Wind Minor
Breezy days Measures: Breezy days (mean wind >=25 km/h). Observed about 1% of days (0.4 days/month) in September. Historical risk signal only, not a day-by-day forecast.
0.4 days / month
~1% of days
Why this matters
- Expected days 0.4 days / month
- Probability ~1% of days
- Intensity Up to ~36km/h (P95)
Breezy conditions are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Heat Minor
Very hot days Measures: Very hot days (>=35C). 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 ~36°C (P95)
Very hot days are possible on ~0 days. Midday activity often needs adjustment around shade, hydration, and indoor fallback options.
Frequently asked questions
Is September a good time to visit Osaka?
Typical September days in Osaka reach highs of 28°C (82°F) with nights around 21°C (70°F). It usually feels hot by day and mild after dark. It is among the wetter months, so it is wise to have some indoor backup plans or flexible activities.
What are temperatures like in September?
Daytime temperatures in September typically peak near 28°C (82°F), while nights drop to around 21°C (70°F). Expect hot afternoons and mild evenings.
How much does it rain in September?
Rainfall in September averages 168 mm (6.6 in) across roughly 15 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 05:40 and sunset near 18:04. Daylight is fairly typical, with enough time for sightseeing.
How strong is the sun in September?
UV levels are often high (around 7). Regular sunscreen and a hat are recommended.
Is it windy in September?
In September, average wind speeds are around 9 km/h (6 mph), with gusts on the windiest days reaching about 49 km/h (30 mph). On the ground, it is it often feels breezy, especially in more exposed spots or along the coast.