Itoshima, Japan experiences average highs of 19°C (66°F) and lows of 14°C (57°F) throughout the year. Rainfall is moderate, averaging about 11 rainy days per month. Average highs have stayed broadly stable across the available records.
Itoshima, Japan Weather & Climate 2026
Monthly climate averages for Itoshima, Japan. Based on 10-year ERA5 reanalysis data.
Climate Overview
Drier season: Jan–Dec 
Wetter season: Mar–Sep At-a-Glance Climate Summary
Live Weather & Air Quality
Key figures
Climate Score
5.9/10
Best: May, June, October
UV Index
5
Low
Temperature 19°C / 14°C
Feels Like 20°C / 14°C
Rainy Days 11
Rainfall 142 mm
Sunshine 8 h
Humidity 77%
Wind Speed 15 km/h
Dew Point 13°C
Snow Days 2 days
Frost Days 1 days
Hottest Month
30°C
August
Avg Low26°C
Rain14days
Coldest Month
5°C
January
Avg High9°C
Rain9days
Driest Month
7days
November
Avg High17°C
Avg Low12°C
Windiest Month
18 km/h
February (Gusts 43)
Sea Temperature
12°C – 29°C
Warmest water: August (
29.3°C
)
Worst Time to Visit
Consider avoiding January, February, July, August due to frequent rain.
Sun Position
Sunrise 05:10
Daylight 14.4h
Sunset 19:32
Live conditions—
Itoshima on the map · live conditions
Itoshima, Japan
- Continent
- Asia
- Country
- Japan
- City
- Itoshima
- Population
- 98.9K
- Coordinates
- 33.54°, 130.18°
Seasonal Breakdown
Spring
Mar–May
Avg High 18°C
Avg Low 12°C
Rain 11 days/mo
1/3 best months
Summer
Jun–Aug
Avg High 28°C
Avg Low 23°C
Rain 15 days/mo
1/3 best months
Autumn
Sep–Nov
Avg High 22°C
Avg Low 17°C
Rain 10 days/mo
1/3 best months
Winter
Dec–Feb
Avg High 10°C
Avg Low 5°C
Rain 9 days/mo
Climate Charts
Based on historical averages (2016–2025)
Monthly Temperatures
HighLowShaded bands show the typical range across the available yearly records.
Line chart showing monthly temperatures. Jan: 9°C / 5°C . Feb: 9°C / 5°C . Mar: 13°C / 8°C . Apr: 18°C / 12°C . May: 22°C / 16°C . Jun: 25°C / 20°C . Jul: 29°C / 24°C . Aug: 30°C / 26°C . Sep: 27°C / 23°C . Oct: 22°C / 17°C . Nov: 17°C / 12°C . Dec: 11°C / 7°C .
Monthly Rainfall
Rainfall
Bar chart showing monthly rainfall. Jan: 70 mm. Feb: 79 mm. Mar: 109 mm. Apr: 132 mm. May: 161 mm. Jun: 245 mm. Jul: 257 mm. Aug: 227 mm. Sep: 190 mm. Oct: 92 mm. Nov: 74 mm. Dec: 63 mm.
Monthly Humidity
Humidity
Line chart showing monthly humidity. Jan: 70%. Feb: 70%. Mar: 74%. Apr: 77%. May: 80%. Jun: 86%. Jul: 86%. Aug: 82%. Sep: 82%. Oct: 76%. Nov: 72%. Dec: 69%.
Monthly Wind Speed
Wind SpeedGusts
Bar chart showing monthly wind speed. Jan: 18 km/h . Feb: 18 km/h . Mar: 17 km/h . Apr: 16 km/h . May: 14 km/h . Jun: 13 km/h . Jul: 13 km/h . Aug: 14 km/h . Sep: 15 km/h . Oct: 16 km/h . Nov: 15 km/h . Dec: 18 km/h .
Sunshine
Sunshine
Sunshine: Jan: 6h. Feb: 7h. Mar: 8h. Apr: 9h. May: 9h. Jun: 8h. Jul: 9h. Aug: 10h. Sep: 8h. Oct: 8h. Nov: 8h. Dec: 6h.
Sea Temperature
Sea Temperatureswim
Line chart showing monthly sea temperature. Jan: 13°C . Feb: 12°C . Mar: 13°C . Apr: 16°C . May: 19°C . Jun: 23°C . Jul: 27°C . Aug: 29°C . Sep: 29°C . Oct: 24°C . Nov: 20°C . Dec: 15°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 7. Jul: UV 8. Aug: UV 7. Sep: UV 6. Oct: UV 5. Nov: UV 4. Dec: UV 3.
Monthly Daylight Hours
Daylight12h reference
Monthly Dew Point & Comfort
Dew Point Dry Comfortable Humid Muggy
Snow Days
Snow DaysSnowfall
Snow Days: Jan: 3 days. Feb: 2 days. Mar: 0 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: 1 days.
Climate Trends
Average highs have stayed broadly stable across the available records. Average rainfall is trending drier by about 44 mm.
2016 to 2025
Avg high Avg rainfall
Climate summary
| Last 12 months | All years | |
|---|---|---|
| Hottest month | Jul 2025 · 31°C | Aug · 30°C |
| Coldest month | Feb 2025 · 3°C | Jan · 5°C |
| Wettest month | Jun 2025 · 358 mm | Jul · 257 mm |
| Windiest month | Feb 2025 · 20 km/h | Feb · 18 km/h |
Month-by-Month Weather Table
January
Poor 
February
Poor March
Fair April
Good May best
Excellent June best
Excellent July
Wet August
Wet September
Wet October best
Excellent November
Good December
Fair | Month | Temp | Feels Like | Rain | Sun | Humidity | UV | Status | Details |
|---|---|---|---|---|---|---|---|---|
| January | 9°C / 5°C | 6°C / 1°C | 9days (70 mm) Wet | 6.4h Fair | 70% Muggy | 3.2 Moderate | Poor | View Details |
| February | 9°C / 5°C | 6°C / 1°C | 9days (79 mm) Wet | 7.3h Good | 70% Muggy | 3.8 Moderate | Poor | View Details |
| March | 13°C / 8°C | 12°C / 5°C | 11days (109 mm) Wet | 8h Good | 74% Muggy | 5.1 High | Fair | View Details |
| April | 18°C / 12°C | 17°C / 10°C | 10days (132 mm) Wet | 8.5h Good | 77% Humid | 5.9 High | Good | View Details |
| May best | 22°C / 16°C | 23°C / 16°C | 11days (161 mm) Wet | 8.9h Good | 80% Humid | 6.4 High | Excellent | View Details |
| June best | 25°C / 20°C | 28°C / 23°C | 14days (245 mm) Wet | 7.8h Good | 86% Very Muggy | 6.5 High | Excellent | View Details |
| July | 29°C / 24°C | 34°C / 29°C | 16days (257 mm) Wet | 9h Good | 86% Very Muggy | 7.5 Very High | Wet | View Details |
| August | 30°C / 26°C | 36°C / 30°C | 14days (227 mm) Wet | 10h Excellent | 82% Humid | 7.4 Very High | Wet | View Details |
| September | 27°C / 23°C | 30°C / 26°C | 15days (190 mm) Wet | 7.9h Good | 82% Humid | 6.3 High | Wet | View Details |
| October best | 22°C / 17°C | 22°C / 17°C | 9days (92 mm) Wet | 7.9h Good | 76% Humid | 4.9 Moderate | Excellent | View Details |
| November | 17°C / 12°C | 15°C / 10°C | 7days (74 mm) Good | 7.6h Good | 72% Muggy | 3.7 Moderate | Good | View Details |
| December | 11°C / 7°C | 8°C / 3°C | 9days (63 mm) Wet | 6.1h Fair | 69% Muggy | 3 Moderate | Fair | View Details |
Compare Nearby City Climates
Frequently Asked Questions
The best months to visit Itoshima are May, June, October, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Itoshima, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Itoshima is August, with average daytime highs of 30°C (86°F). Plan outdoor activities for early morning or late afternoon if visiting during this period.
The coldest month in Itoshima is January, with average overnight lows of 5°C (41°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Itoshima is July, averaging 257mm of precipitation across 16 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Itoshima runs through July, September, June, August, with the heaviest rainfall in July. Based on 10-year averages for Itoshima.
Itoshima receives approximately 95 sunshine hours per year. The sunniest month is August with around 10 hours. Based on climate data for Itoshima.
The least favorable months to visit Itoshima are January, February, July, August, primarily due to frequent rain. For the best conditions, consider May, June, October instead.
The annual average UV index in Itoshima is 5, classified as moderate. Standard sun protection (sunscreen, hat) is recommended during prolonged outdoor exposure.
Average humidity in Itoshima 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 26°C (79°F), which is warm and comfortable for swimming and water activities.
Yes, Itoshima receives snow. Months with snowfall average 2 snow days and 2 cm (1 in) of accumulation, with about 1 frost days during winter.
Average wind speeds in Itoshima are 15 km/h (9 mph). The windiest month is February with peak winds reaching 18 km/h (11 mph) (gusts up to 43 km/h / 27 mph).
Itoshima averages 3 clear-sky days per month with overall cloud cover around 63%. The clearest skies occur in November.
The annual average dew point in Itoshima is 13°C (55°F), which feels pleasant with low humidity. Outdoor activities are comfortable year-round from a humidity standpoint.
Itoshima 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 Itoshima ranges from 14°C (57°F) to 20°C (68°F) on average. The 'feels like' temperature closely matches the actual temperature throughout most of the year.
Yes, June is a great time to visit Itoshima. It earns a climate score of 8/10 with Excellent.
For June in Itoshima, pack Umbrella, Waterproof jacket, Waterproof shoes, Breathable clothing, Sunscreen (SPF 30+). With average highs of 25°C (76°F) and 14 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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