Monthly weather averages & travel planning

Asia › 🇯🇵 Japan › Osaka
Updated: March 2026
August is a fair time to visit Osaka (5/10). With 11 daily sunshine hours and only 12 rain days, this month delivers genuinely reliable outdoor conditions, ranking it the sunniest month of the year in Osaka. Culture-focused travellers and those who prefer lighter crowds will find August a practical choice, with prices running lower than peak August without sacrificing all the good weather. July offers a similar profile at lower hotel rates if dates are flexible. The main practical note: Osaka's popular sites are busiest between 10am and 3pm regardless of season. Arriving at opening time or after 4pm makes a significant difference to the experience. Planning tips: accommodation is generally available without long lead times, and flight prices are typically lower than peak season. Flexible travellers will find the best deals by booking 2-4 weeks ahead. Mid-week arrivals consistently unlock lower hotel rates than weekend check-ins.
The single most important thing to know about visiting Osaka in August: the heat is serious at 32°C and demands sun protection, hydration, and shade-seeking between noon and 15:00. Precipitation totals 108mm for the month, spread across roughly 12 days, and 11 sunshine hours per day give you a reliable window for outdoor plans.
32°C
90°F
Avg High
24°C
75°F
Avg Low
12 days
108 mm total
Rain Days
11h
per day avg
Sunshine
70%
Moderate
Humidity
The 8°C day-night temperature range is typical for continental climates: a light jacket in the morning that you shed by midday and need again after sunset. Humidity averages 70%, which is comfortable for most visitors. On warmer days, lighter fabrics help with the mild stickiness in the afternoon. UV index averages 9 this month, classed as high to very high. SPF 30+ sunscreen, a brim hat, and sunglasses are not optional between 10am and 4pm. Wind averages 15 km/h, light enough to be refreshing on warm days but noticeable in open coastal areas or elevated viewpoints. In Fahrenheit: 90°F average high, 75°F overnight low. Data sourced from Open-Meteo ERA5 climate reanalysis (1991–2020 normals).
Packing for Osaka in August means dressing for 32°C days and 24°C evenings. A lightweight linen or cotton shirt with loose-fit trousers or a sundress handles the 32°C daytime heat. Evening temperatures settle at 24°C, a modest 8°C drop that a light cardigan or denim jacket covers. For footwear, breathable walking sandals work for casual exploration, but closed-toe trainers are better for uneven surfaces in the historic centre. A compact foldable umbrella weighs almost nothing and earns its keep across 12 potential rainy days. For temple and religious site visits, carry a lightweight scarf or sarong to cover shoulders and knees, required at most major sites across the region.
Local tip: Temple and religious site visits require covered shoulders and knees in most of Osaka's heritage areas. A lightweight scarf or sarong weighs almost nothing and solves the problem instantly.
August has no major festivals or public holidays in Osaka, which is one of its practical advantages for independent travellers. Attractions run at lower capacity than during peak event periods, queues are shorter, and accommodation is easier to find without needing to book many months in advance. Local restaurants, markets, and transport operate at a relaxed pace, making this an ideal time for visitors who prefer a more authentic, unhurried experience of everyday city life rather than large crowds drawn in by a single major headline event.
Based on 32°C average highs and 12 rainy days
Osaka's August heat is driven by the Asian summer monsoon system, as the low-pressure cell that forms over the heated landmass draws warm, humid air from the oceans. The result is temperatures averaging 32°C with high moisture in the air. Overnight temperatures remain elevated at 24°C, as clouds and humidity prevent the earth from radiating heat away after sunset. Climate data: Open-Meteo ERA5 (1991–2020).
Sunshine Hours
The average number of hours per day with direct sunlight. Calculated from satellite measurements. Days with more than 7 hours of sunshine are ideal for outdoor activities. Under 3 hours means overcast conditions dominate.
UV Index
A scale from 0-11+ measuring ultraviolet radiation intensity. UV 0-2: Minimal risk. UV 3-5: Moderate, wear sunscreen. UV 6-7: High, hat and SPF 30+ essential. UV 8-10: Very High, limit midday exposure. UV 11+: Extreme, seek shade between 10am-4pm.
Rain Days
A rain day is counted when precipitation exceeds 0.1mm. This threshold captures even light drizzle. Unlike total rainfall in mm, rain days tells you how often you might need an umbrella, which is useful for planning outdoor activities.
Humidity
Relative humidity as a percentage. Below 40%: Dry, skin and throat may feel parched. 40-60%: Comfortable, ideal for most people. 60-80%: Sticky, light breathable fabrics recommended. Above 80%: Muggy, heat feels more intense; quick-dry clothing is essential.
Osaka in August
August ranks 1st sunniest of the year in Osaka, with an average 11 daily sunshine hours. The driest months are January, December, and February. August is the hottest month (32°C avg high); January is the coolest (8°C). From here, temperatures fall 4°C into September. Compared to last month (July: 30°C high, 14 rain days), August is warmer and drier. August is among the top three sunniest months to visit Osaka.
| Month | High | Low | Rain Days | Sun | Details |
|---|---|---|---|---|---|
| January | 8°C | 1°C | 6 | 8h | View |
| February | 9°C | 1°C | 8 | 8h | View |
| March | 13°C | 4°C | 11 | 9h | View |
| April | 18°C | 9°C | 10 | 9h | View |
| May | 23°C | 15°C | 10 | 10h | View |
| June | 26°C | 19°C | 13 | 9h | View |
| July | 30°C | 23°C | 14 | 10h | View |
| August | 32°C | 24°C | 12 | 11h | View |
| September | 28°C | 21°C | 12 | 9h | View |
| October | 22°C | 15°C | 10 | 8h | View |
| November | 16°C | 9°C | 8 | 8h | View |
| December | 11°C | 4°C | 7 | 8h | View |
January
6 rain days, 8h sun
February
8 rain days, 8h sun
March
11 rain days, 9h sun
April
10 rain days, 9h sun
May
10 rain days, 10h sun
June
13 rain days, 9h sun
July
14 rain days, 10h sun
August
12 rain days, 11h sun
September
12 rain days, 9h sun
October
10 rain days, 8h sun
November
8 rain days, 8h sun
December
7 rain days, 8h sun
Cities within 500 km with comparable weather conditions
Data Sources for Osaka
Climate normals represent 30-year averages (1991-2020). Individual years may vary.