August 21 is generally a great time to visit Osaka. While there is a slight chance of rain (33%), showers are usually brief. Expect comfortable 32°C weather. Expect a bustling atmosphere in Osaka right now—this is when the city truly comes alive with visitors.
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Essential Travel Info for Osaka
Currency
JPY
¥ Japanese yen
Language
Japanese
Driving
Left side
Safety
Very High Safety
GPI: 1.336
Osaka Weather Forecast for August 21
"Warm & Sunny. Expect average highs of 31.9°C. 33% chance of rain."
What to Wear in Osaka in August
Based on historical data for August 21, Osaka typically experiences temperatures between 25°C and 31.9°C. We recommend packing t-shirt, light clothing, umbrella to stay comfortable. With a 33% chance of rain, keeping a raincoat or umbrella handy is a smart move.
Complete Packing Guide
Weekly breakdown & essential items for Osaka
Smart Suitcase
- T-Shirt
- Light Clothing
- Umbrella
Average High
31.9°C
Daytime Peak
Average Low
25°C
Nighttime Low
Feels Like
42°C
🔥 Heat index effect
Rain Chance
33%
Avg 2.5mm if it rains
Cloud Cover
60%
Light drizzle
Pressure
1010 hPa
Low volatility
Osaka Weather Conditions & UV Index
Weather Confidence
30-year variance analysis
Based on 10 years of data
🎯 This date historically delivers consistent weather 92% of the time. Safe to plan outdoor activities with confidence.
Sun Exposure
UV Index & Safety Guide
Protection Needed
SPF 30 recommended
05:00 - 10:00
16:00 - 18:00
Type I-II
🔴 19 min to burn
Type III-IV
🟡 29 min to burn
Type V-VI
🟢 48 min to burn
UV estimate based on latitude, season & cloud cover. Actual UV may vary.
Outdoor Comfort
How pleasant is it outside?
Dew Point
26.9°C
Humid/Sticky
Heat Index
42°C
Feels hotter
😕 Best outdoor time:
Early morning (6-9 AM) or evening (after 6 PM)
Marine Conditions
Jellyfish Warning
High water temps may attract jellyfish swarms.
Swim Index
✅ Excellent Swimming Conditions
Travel & Logistics Insights
Local Calendar
Business Day
Standard hours in Japan
Flight Traffic
High
98/100 pressure index
Health Advisory
Required
1 vaccine • View Details →
Landing Slots
~275
Daily arrival options (inc. codeshare)
Sunrise, Sunset & Wind in Osaka
Daylight & Sun
Solar Elevation Cycle
🌅 Sunrise
05:23
☀️ Noon
12:02
🌇 Sunset
18:41
⏱️ Daylight
13h 17m
Wind Speed
13.8 km/h
Gentle breeze
Sunshine
10.3 hrs
Direct Sun (Cloud-free)
Humidity
75%
Humid / Damp
Travel Intelligence
Exclusive flight analytics & health data for Osaka
Smart Flight Estimator
Airport-to-Airport Logistics
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Travel Health & Safety in Osaka
Travel Comfort Index
Real-time tourism conditions
Weather Quality
⛅ Good
Tourist Crowds
🔴 Very Busy
Price Level
💰💰💰 Expensive
Health & Wellbeing
Meteo-Health Forecast
Stable conditions. Low risk of headaches.
Mild discomfort possible for arthritic conditions.
Moderate fish activity expected.
Air quality is acceptable. Sensitive individuals should limit prolonged outdoor exertion.
Regional Safety Profile
Seismic Activity
Active seismic zone. Multiple earthquakes per year.
Typhoon Risk
Year-round risk present
Travel Alert: This region has elevated natural risks. We recommend registering with your embassy and keeping emergency numbers handy.
"According to 30YearWeather's analysis of 30 years of NASA satellite data, Osaka on August 21 averages 31.9°C with a 33% precipitation probability. Wedding/Outdoor Event Score: 86/100."
— Source: 30YearWeather.com|Data: NASA POWER (1991-2021)|View Methodology
Osaka Weather History (2010–2024)
Temperature History
Hall of Fame
Records from last 10 years
Better Alternatives Nearby
Consider these dates within ±7 days
August 19
32°C • 28% rain
Score
96
August 20
32°C • 30% rain
Score
95
August 15
32°C • 38% rain
Score
91
💡 Moving your event by a few days could significantly improve weather conditions
Compare Other Cities
Same date (August 21) in other destinations
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📍 Is Osaka Worth Visiting on August 21?
Planning a trip to Osaka on August 21? Our historical weather analysis based on 30 years of NASA satellite data shows that this time of year typically offers vibrant summer conditions averaging 31.9°C with a 33% historical precipitation risk.
✈️ Travel Logistics: Approximately 275 landing slots available daily during this period, indicating manageable crowd levels.
💉 Health Advisory: 8 vaccinations are recommended for Japan, including COVID-19.
🌊 Coastal Conditions: Water temperature averages 29.9°C (hot soup). Wave conditions are generally lake-like with heights around 0.21m.
📊 Historical Extremes: The hottest August 21 recorded in the last 30 years saw temperatures hit 36.4°C in 2020, while the coldest dropped to 23°C in 2021.