Usui, Japan experiences average highs of 20°C (68°F) and lows of 13°C (55°F) throughout the year. Rainfall is moderate, averaging about 12 rainy days per month. Average highs have warmed by 1.0°C (1.8°F) across the available records.
Usui, Japan Weather & Climate 2026
Monthly climate averages for Usui, Japan. Based on 10-year ERA5 reanalysis data.
Climate Overview
Drier season: Jan–Dec 
Wetter season: Mar–Oct At-a-Glance Climate Summary
Live Weather & Air Quality
Key figures
Climate Score
6/10
Best: May, June, September, October, November
UV Index
5
Low
Temperature 20°C / 13°C
Feels Like 20°C / 13°C
Rainy Days 12
Rainfall 125 mm
Sunshine 8 h
Humidity 77%
Wind Speed 18 km/h
Dew Point 12°C
Snow Days 1 days
Frost Days 5 days
Hottest Month
31°C
August
Avg Low 25°C
Rain 13 days
Coldest Month
2°C
January
Avg High 9°C
Rain 6 days
Driest Month
6 days
January
Avg High 9°C
Avg Low 2°C
Windiest Month
21 km/h
April (Gusts 41)
Sea Temperature
8°C – 30°C
Warmest water: August (
30.2°C
)
Worst Time to Visit
Consider avoiding January, February, August, December due to less favorable weather conditions.
Sun Position
Sunrise 04:34
Daylight 14.4h
Sunset 18:56
Live conditions —
Usui on the map · live conditions
Usui, Japan
- Continent
- Asia
- Country
- Japan
- City
- Usui
- Population
- 7.4K
- Coordinates
- 35.73°, 140.18°
Seasonal Breakdown
Spring
Mar–May
Avg High 18°C
Avg Low 11°C
Rain 12 days/mo
1/3 best months
Summer
Jun–Aug
Avg High 29°C
Avg Low 23°C
Rain 13 days/mo
1/3 best months
Autumn
Sep–Nov
Avg High 22°C
Avg Low 16°C
Rain 13 days/mo
3/3 best months
Winter
Dec–Feb
Avg High 10°C
Avg Low 3°C
Rain 7 days/mo
Climate Charts
Based on historical averages (2016–2025)
Monthly Temperatures
High Low Shaded bands show the typical range across the available yearly records.
Line chart showing monthly temperatures. Jan: 9°C / 2°C . Feb: 10°C / 3°C . Mar: 14°C / 7°C . Apr: 18°C / 11°C . May: 23°C / 16°C . Jun: 26°C / 20°C . Jul: 30°C / 24°C . Aug: 31°C / 25°C . Sep: 27°C / 22°C . Oct: 21°C / 16°C . Nov: 16°C / 10°C . Dec: 11°C / 4°C .
Monthly Rainfall
Rainfall
Bar chart showing monthly rainfall. Jan: 57 mm. Feb: 61 mm. Mar: 130 mm. Apr: 122 mm. May: 141 mm. Jun: 187 mm. Jul: 165 mm. Aug: 116 mm. Sep: 170 mm. Oct: 186 mm. Nov: 100 mm. Dec: 61 mm.
Monthly Humidity
Humidity
Line chart showing monthly humidity. Jan: 70%. Feb: 68%. Mar: 74%. Apr: 74%. May: 77%. Jun: 81%. Jul: 83%. Aug: 81%. Sep: 82%. Oct: 80%. Nov: 78%. Dec: 73%.
Monthly Wind Speed
Wind Speed Gusts
Bar chart showing monthly wind speed. Jan: 18 km/h . Feb: 20 km/h . Mar: 20 km/h . Apr: 21 km/h . May: 20 km/h . Jun: 17 km/h . Jul: 17 km/h . Aug: 18 km/h . Sep: 18 km/h . Oct: 17 km/h . Nov: 16 km/h . Dec: 17 km/h .
Sunshine
Sunshine
Sunshine: Jan: 8h. Feb: 8h. Mar: 8h. Apr: 9h. May: 9h. Jun: 9h. Jul: 9h. Aug: 10h. Sep: 8h. Oct: 7h. Nov: 7h. Dec: 7h.
Sea Temperature
Sea Temperature swim
Line chart showing monthly sea temperature. Jan: 8°C . Feb: 8°C . Mar: 11°C . Apr: 15°C . May: 19°C . Jun: 23°C . Jul: 28°C . Aug: 30°C . Sep: 29°C . Oct: 22°C . Nov: 17°C . Dec: 12°C .
UV Index
UV Index
Bar chart showing monthly UV index. Jan: UV 3. Feb: UV 4. Mar: UV 5. Apr: UV 6. May: UV 6. Jun: UV 6. Jul: UV 7. Aug: UV 7. Sep: UV 6. Oct: UV 4. Nov: UV 3. Dec: UV 3.
Monthly Daylight Hours
Daylight 12h reference
Monthly Dew Point & Comfort
Dew Point Dry Comfortable Humid Muggy
Snow Days
Snow Days Snowfall
Snow Days: Jan: 1 days. Feb: 2 days. Mar: 1 days. Apr: 0 days. May: 0 days. Jun: 0 days. Jul: 0 days. Aug: 0 days. Sep: 0 days. Oct: 0 days. Nov: 0 days. Dec: 0 days.
Climate Trends
Average highs have warmed by 1.0°C (1.8°F) across the available records. Average rainfall is trending drier by about 29 mm.
2016 to 2025
Avg high Avg rainfall
Climate summary
| Last 12 months | All years | |
|---|---|---|
| Hottest month | Aug 2025 · 33°C | Aug · 31°C |
| Coldest month | Feb 2025 · 1°C | Jan · 2°C |
| Wettest month | May 2025 · 181 mm | Jun · 187 mm |
| Windiest month | Feb 2025 · 21 km/h | Apr · 21 km/h |
Month-by-Month Weather Table
January
Poor 
February
Poor March
Fair April
Good May best
Excellent June best
Excellent July
Fair August
Poor September best
Good October best
Excellent November best
Good December
Fair | Month | Temp | Feels Like | Rain | Sun | Humidity | UV | Status | Details |
|---|---|---|---|---|---|---|---|---|
| January | 9°C / 2°C | 5°C / -2°C | 6days (57 mm) Good | 7.7h Good | 70% Muggy | 3.2 Moderate | Poor | View Details |
| February | 10°C / 3°C | 7°C / -1°C | 9days (61 mm) Wet | 8.2h Good | 68% Muggy | 3.9 Moderate | Poor | View Details |
| March | 14°C / 7°C | 12°C / 3°C | 13days (130 mm) Wet | 7.9h Good | 74% Muggy | 4.6 Moderate | Fair | View Details |
| April | 18°C / 11°C | 17°C / 9°C | 12days (122 mm) Wet | 8.7h Good | 74% Muggy | 5.5 High | Good | View Details |
| May best | 23°C / 16°C | 23°C / 15°C | 12days (141 mm) Wet | 8.9h Good | 77% Humid | 5.8 High | Excellent | View Details |
| June best | 26°C / 20°C | 28°C / 21°C | 14days (187 mm) Wet | 8.6h Good | 81% Humid | 6.4 High | Excellent | View Details |
| July | 30°C / 24°C | 34°C / 27°C | 13days (165 mm) Wet | 9.3h Good | 83% Humid | 7.4 Very High | Fair | View Details |
| August | 31°C / 25°C | 36°C / 29°C | 13days (116 mm) Wet | 10.3h Excellent | 81% Humid | 7.2 Very High | Poor | View Details |
| September best | 27°C / 22°C | 30°C / 25°C | 15days (170 mm) Wet | 8h Good | 82% Humid | 5.8 High | Good | View Details |
| October best | 21°C / 16°C | 22°C / 15°C | 14days (186 mm) Wet | 6.6h Fair | 80% Humid | 3.9 Moderate | Excellent | View Details |
| November best | 16°C / 10°C | 15°C / 8°C | 10days (100 mm) Wet | 7.1h Good | 78% Humid | 3.1 Moderate | Good | View Details |
| December | 11°C / 4°C | 9°C / 1°C | 7days (61 mm) Good | 7.3h Good | 73% Muggy | 2.9 Moderate | Fair | View Details |
Compare Nearby City Climates
Frequently Asked Questions
The best months to visit Usui are May, June, September, October, November, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Usui, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Usui is August, with average daytime highs of 31°C (88°F). Plan outdoor activities for early morning or late afternoon if visiting during this period.
The coldest month in Usui is January, with average overnight lows of 2°C (35°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Usui is June, averaging 187mm of precipitation across 14 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Usui runs through September, June, October, March, with the heaviest rainfall in September. Based on 10-year averages for Usui.
Usui receives approximately 99 sunshine hours per year. The sunniest month is August with around 10 hours. Based on climate data for Usui.
The least favorable months to visit Usui are January, February, August, December, primarily due to less favorable weather conditions. For the best conditions, consider May, June, September, October, November instead.
The annual average UV index in Usui is 5, classified as moderate. Standard sun protection (sunscreen, hat) is recommended during prolonged outdoor exposure.
Average humidity in Usui is 77%, classified as humid. Humidity levels are generally comfortable and should not affect outdoor activities for most people.
Yes — sea temperatures in June, July, August, September, October average 27°C (81°F), which is warm and comfortable for swimming and water activities.
Yes, Usui receives snow. Months with snowfall average 1 snow days and 2 cm (1 in) of accumulation, with about 5 frost days during winter.
Average wind speeds in Usui are 18 km/h (11 mph). The windiest month is April with peak winds reaching 21 km/h (13 mph) (gusts up to 41 km/h / 26 mph).
Usui averages 5 clear-sky days per month with overall cloud cover around 60%. The clearest skies occur in January.
The annual average dew point in Usui is 12°C (54°F), which feels pleasant with low humidity. Outdoor activities are comfortable year-round from a humidity standpoint.
Usui has a Humid Subtropical climate, classified as Cfa under the Köppen system. Temperate climates have mild winters and warm summers, with rainfall spread across the year and four distinct seasons.
The 'feels like' temperature in Usui ranges from 13°C (55°F) to 20°C (68°F) on average. The 'feels like' temperature closely matches the actual temperature throughout most of the year.
July is not the best time to visit Usui, with a climate score of 5.7/10. Consider visiting during May, June, September, October, November instead for better conditions.
For July in Usui, pack Umbrella, Waterproof jacket, Breathable clothing, Sunscreen (SPF 30+), Sun hat. With average highs of 30°C (85°F) and 13 rainy days, these essentials will keep you comfortable.
Data Source
Climate data derived from ERA5 reanalysis (ECMWF), averaged over 2016–2025. Sea surface temperature from marine reanalysis data. Climate scores and seasonal estimates are computed by WorldStats.
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