Kosai Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Kosai.
Climate overview of Kosai
Kosai, Shizuoka, Japan, experiences significant temperature variation throughout the year. Summers bring daytime highs of 32°C (90°F) in August, while winters cool to 11°C (52°F) in January.
With around 1985 mm (78 in) of annual rainfall, Kosai has a notably wet climate. However, this rainfall is not evenly distributed, the city has a distinct rainy season from May to July, with very warm summers and cold winters. The wettest month is June. The sunniest month is August, with 7.1 hours of sunshine per day on average.
Kosai Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Kosai - and find the best time to visit.
Monthly Temperature in Kosai
Depending on the time of the year, temperatures range from very warm to chilly in Kosai. Average daytime temperatures reach a very warm 32°C (90°F) in August. In January, the coolest month of the year, temperatures drop to a chilly 11°C (52°F).
At night, temperatures range from around 25°C (77°F) in August to 3°C (37°F) in January.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Kosai
Kosai has a relatively rainy climate with high precipitation levels, averaging 1985 mm (78 in) of rainfall annually. Kosai can be quite wet during June, receiving approximately 264 mm (10 in) of precipitation over 18 rainy days.
In contrast, during the driest month (January), you will experience much drier conditions, with 71 mm (2.8 in) of precipitation spread across 11 rainy days. For more details, please visit our Kosai Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in Kosai
Kosai experiences moderate variation in sunshine hours across the seasons. With 7.1 hours daily sunshine in August, it dips to 5.0 hours in June, offering a balanced mix of sunny and overcast days.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Humidity in Kosai by Month
The relative humidity is high throughout the year in Kosai.
The city experiences its highest humidity in June, reaching 77%. In February, the humidity drops to its lowest level at 55%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Best Time to Visit Kosai
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: April and May
- Warmest weather: July and August
- Most sunshine: January, March, May, August and December
- Fewest rainy days: January, November and December
- Seasonal pattern: A distinct rainy season from May to July, with very warm summers and cold winters
Frequently asked questions about the climate in Kosai
What is the best time to visit Kosai?
April and May typically offer the most optimal weather in Kosai. In contrast, February, June and July tend to have less optimal conditions. Kosai has a distinct rainy season from May to July, with very warm summers and cold winters.
What temperatures can I expect in Kosai?
Daytime highs range from 11°C (52°F) in January to 32°C (90°F) in August. Nighttime lows range from 3°C (37°F) to 25°C (77°F). Temperatures vary considerably through the year.
How much rain does Kosai get?
Annual rainfall is around 1985 mm (78 in). June is the wettest month with 264 mm (10 in), while January is the driest with 71 mm (2.8 in).
How sunny is Kosai?
Kosai receives around 2,256 hours of sunshine per year. August is the sunniest month with 212 hours, while June is the cloudiest with just 151 hours. Overall, Kosai enjoys abundant sunshine.
Kosai 3-Day Forecast
Kosai on the map
Kosai is highlighted - select any city to see its climate.
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