Achi Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Achi.
Climate overview of Achi
The climate in Achi, Nagano Prefecture, Japan, is marked by large temperature swings across the seasons, ranging from 28°C (82°F) in August to 4°C (39°F) in January.
The city receives considerable rain/snowfall, with around 2323 mm (91 in) annually. July is the wettest month. It has a distinct rainy season from March to October, with warm summers and cold winters. Sunshine peaks in August, when the city sees around 6.8 hours of sunshine per day.
Achi Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Achi - and find the best time to visit.
Monthly Temperature in Achi
In Achi, temperatures differ significantly between summer and winter months. Typically, average maximum daytime temperatures range from a comfortable 28°C (82°F) in August to a chilly 4°C (39°F) in the coolest month, January.
Nights vary from 19°C (66°F) in August to around -6°C (21°F) during the colder months.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Achi
Achi experiences significant rain/snowfall throughout the year, averaging 2323 mm (91 in) of precipitation annually. The climate in Achi shows significant variation throughout the year. Expect heavy rainfall in July, the wettest month, with an average of 322 mm (13 in) of precipitation over 22 rainy days.
In contrast, the driest month December offers drier and sunnier days, with around 103 mm (4.1 in) of snow/rainfall over 16 snowy/rainy days. For more details, please visit our Achi 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 Achi
Achi offers a pleasant mix of sunny and slightly overcast days. The difference in sunshine hours between August (6.8 hours daily) and June (5.0 hours daily) provides a bit of variety for visitors and residents.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Humidity in Achi by Month
The relative humidity is high throughout the year in Achi.
The city experiences its highest humidity in July, reaching 73%. In March, the humidity drops to its lowest level at 59%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Best Time to Visit Achi
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: May, August and September
- Warmest weather: July and August
- Most sunshine: May and August
- Seasonal pattern: A distinct rainy season from March to October, with warm summers and cold winters
- Coldest conditions: January, with freezing nights around -6°C (21°F).
Frequently asked questions about the climate in Achi
What is the best time to visit Achi?
May, August and September typically offer the most optimal weather in Achi. In contrast, January, February, March, April, June, July, October, November and December tend to have less optimal conditions. Achi has a distinct rainy season from March to October, with warm summers and cold winters.
What temperatures can I expect in Achi?
Daytime highs range from 4°C (39°F) in January to 28°C (82°F) in August. Nighttime lows range from -6°C (21°F) to 19°C (66°F). Temperatures vary considerably through the year.
How much rain does Achi get?
Annual rainfall is around 2323 mm (91 in). July is the wettest month with 322 mm (13 in), while December is the driest with 103 mm (4.1 in).
How sunny is Achi?
Achi receives around 2,084 hours of sunshine per year. August is the sunniest month with 203 hours, while June is the cloudiest with just 149 hours. Overall, Achi enjoys abundant sunshine.
Achi 3-Day Forecast
Achi on the map
Achi is highlighted - select any city to see its climate.
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