Kai, Japan experiences average highs of 19°C (66°F) and lows of 11°C (52°F) throughout the year. Rainfall is frequent, averaging about 13 rainy days per month. Average highs have warmed by 0.6°C (1.1°F) across the available records.
Kai, Japan Weather & Climate 2026
Monthly climate averages for Kai, Japan. Based on 10-year ERA5 reanalysis data.
Climate Overview
Drier season: Jan–Dec 
Wetter season: Jun–Oct At-a-Glance Climate Summary
Live Weather & Air Quality
Key figures
Climate Score
5.4/10
Best: April, May, June, September, October
UV Index
5
Low
Temperature 19°C / 11°C
Feels Like 19°C / 11°C
Rainy Days 13
Rainfall 132 mm
Sunshine 8 h
Humidity 75%
Wind Speed 9 km/h
Dew Point 11°C
Snow Days 8 days
Frost Days 8 days
Hottest Month
30°C
August
Avg Low 23°C
Rain 18 days
Coldest Month
0°C
January
Avg High 8°C
Rain 6 days
Driest Month
6 days
January
Avg High 8°C
Avg Low 0°C
Windiest Month
11 km/h
February (Gusts 44)
Worst Time to Visit
Consider avoiding January, February, July, December due to less favorable weather conditions.
Sun Position
Sunrise 04:41
Daylight 14.3h
Sunset 19:02
Live conditions —
Kai on the map · live conditions
Kai, Japan
- Continent
- Asia
- Country
- Japan
- City
- Kai
- Population
- 75.3K
- Coordinates
- 35.68°, 138.51°
Seasonal Breakdown
Spring
Mar–May
Avg High 18°C
Avg Low 9°C
Rain 13 days/mo
2/3 best months
Summer
Jun–Aug
Avg High 28°C
Avg Low 21°C
Rain 18 days/mo
1/3 best months
Autumn
Sep–Nov
Avg High 21°C
Avg Low 13°C
Rain 13 days/mo
2/3 best months
Winter
Dec–Feb
Avg High 9°C
Avg Low 1°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: 8°C / 0°C . Feb: 9°C / 1°C . Mar: 13°C / 4°C . Apr: 19°C / 9°C . May: 23°C / 14°C . Jun: 26°C / 18°C . Jul: 29°C / 22°C . Aug: 30°C / 23°C . Sep: 26°C / 19°C . Oct: 20°C / 13°C . Nov: 15°C / 7°C . Dec: 10°C / 2°C .
Monthly Rainfall
Rainfall
Bar chart showing monthly rainfall. Jan: 52 mm. Feb: 71 mm. Mar: 131 mm. Apr: 125 mm. May: 152 mm. Jun: 183 mm. Jul: 224 mm. Aug: 153 mm. Sep: 179 mm. Oct: 187 mm. Nov: 73 mm. Dec: 49 mm.
Monthly Humidity
Humidity
Line chart showing monthly humidity. Jan: 64%. Feb: 63%. Mar: 69%. Apr: 71%. May: 73%. Jun: 79%. Jul: 84%. Aug: 83%. Sep: 84%. Oct: 82%. Nov: 76%. Dec: 68%.
Monthly Wind Speed
Wind Speed Gusts
Bar chart showing monthly wind speed. Jan: 11 km/h . Feb: 11 km/h . Mar: 10 km/h . Apr: 11 km/h . May: 9 km/h . Jun: 8 km/h . Jul: 7 km/h . Aug: 7 km/h . Sep: 8 km/h . Oct: 8 km/h . Nov: 8 km/h . Dec: 10 km/h .
Sunshine
Sunshine
Sunshine: Jan: 8h. Feb: 9h. Mar: 9h. Apr: 9h. May: 9h. Jun: 9h. Jul: 9h. Aug: 10h. Sep: 8h. Oct: 7h. Nov: 8h. Dec: 8h.
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 7. Aug: UV 7. Sep: UV 6. Oct: UV 5. Nov: UV 4. Dec: UV 3.
Monthly Daylight Hours
Daylight 12h reference
Monthly Dew Point & Comfort
Dew Point Dry Comfortable Humid Muggy Oppressive
Snow Days
Snow Days Snowfall
Snow Days: Jan: 11 days. Feb: 11 days. Mar: 11 days. Apr: 2 days. May: 0 days. Jun: 0 days. Jul: 0 days. Aug: 0 days. Sep: 0 days. Oct: 0 days. Nov: 2 days. Dec: 8 days.
Climate Trends
Average highs have warmed by 0.6°C (1.1°F) across the available records. Average rainfall is trending drier by about 31 mm.
2016 to 2025
Avg high Avg rainfall
Climate summary
| Last 12 months | All years | |
|---|---|---|
| Hottest month | Aug 2025 · 32°C | Aug · 30°C |
| Coldest month | Feb 2025 · -1°C | Jan · 0°C |
| Wettest month | Sep 2025 · 187 mm | Jul · 224 mm |
| Windiest month | Feb 2025 · 12 km/h | Feb · 11 km/h |
Month-by-Month Weather Table
January
Poor 
February
Poor March
Fair April best
Good May best
Excellent June best
Excellent July
Wet August
Wet September best
Excellent October best
Wet November
Fair December
Poor | Month | Temp | Feels Like | Rain | Sun | Humidity | UV | Status | Details |
|---|---|---|---|---|---|---|---|---|
| January | 8°C / 0°C | 4°C / -3°C | 6days (52 mm) Good | 8.1h Good | 64% Muggy | 3.4 Moderate | Poor | View Details |
| February | 9°C / 1°C | 5°C / -3°C | 8days (71 mm) Wet | 8.7h Good | 63% Muggy | 4.2 Moderate | Poor | View Details |
| March | 13°C / 4°C | 11°C / 1°C | 13days (131 mm) Wet | 8.5h Good | 69% Muggy | 5.1 High | Fair | View Details |
| April best | 19°C / 9°C | 18°C / 7°C | 12days (125 mm) Wet | 9.2h Good | 71% Muggy | 6.1 High | Good | View Details |
| May best | 23°C / 14°C | 24°C / 14°C | 13days (152 mm) Wet | 9.2h Good | 73% Muggy | 6.3 High | Excellent | View Details |
| June best | 26°C / 18°C | 28°C / 20°C | 16days (183 mm) Wet | 8.8h Good | 79% Humid | 6.7 High | Excellent | View Details |
| July | 29°C / 22°C | 34°C / 26°C | 19days (224 mm) Wet | 8.7h Good | 84% Humid | 7.4 Very High | Wet | View Details |
| August | 30°C / 23°C | 35°C / 27°C | 18days (153 mm) Wet | 9.8h Good | 83% Humid | 7.3 Very High | Wet | View Details |
| September best | 26°C / 19°C | 30°C / 22°C | 16days (179 mm) Wet | 7.9h Good | 84% Humid | 6.3 High | Excellent | View Details |
| October best | 20°C / 13°C | 21°C / 13°C | 15days (187 mm) Wet | 7.1h Good | 82% Humid | 4.6 Moderate | Wet | View Details |
| November | 15°C / 7°C | 14°C / 5°C | 8days (73 mm) Wet | 7.7h Good | 76% Humid | 3.8 Moderate | Fair | View Details |
| December | 10°C / 2°C | 7°C / -1°C | 6days (49 mm) Good | 7.8h Good | 68% Muggy | 3.1 Moderate | Poor | View Details |
Compare Nearby City Climates
Frequently Asked Questions
The best months to visit Kai are April, May, June, September, October, when temperatures are comfortable and rainfall is at its lowest. This is based on 10-year climate averages for Kai, scoring temperature, rainfall, humidity, and sunshine hours.
The hottest month in Kai 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 Kai is January, with average overnight lows of 0°C (32°F). Pack warm layers and expect shorter daylight hours during this period.
The wettest month in Kai is July, averaging 224mm of precipitation across 19 rainy days. An umbrella or waterproof jacket is essential.
The rainy season in Kai runs through July, August, June, September, with the heaviest rainfall in July. Based on 10-year averages for Kai.
Kai receives approximately 102 sunshine hours per year. The sunniest month is August with around 10 hours. Based on climate data for Kai.
The least favorable months to visit Kai are January, February, July, December, primarily due to less favorable weather conditions. For the best conditions, consider April, May, June, September, October instead.
The annual average UV index in Kai is 5, classified as moderate. Standard sun protection (sunscreen, hat) is recommended during prolonged outdoor exposure.
Average humidity in Kai is 75%, classified as moderate. Humidity levels are generally comfortable and should not affect outdoor activities for most people.
Yes, Kai receives snow. Months with snowfall average 8 snow days and 16 cm (6 in) of accumulation, with about 8 frost days during winter.
Average wind speeds in Kai are 9 km/h (6 mph). The windiest month is February with peak winds reaching 11 km/h (7 mph) (gusts up to 44 km/h / 27 mph).
Kai averages 3 clear-sky days per month with overall cloud cover around 62%. The clearest skies occur in December.
The annual average dew point in Kai is 11°C (52°F), which feels pleasant with low humidity. Outdoor activities are comfortable year-round from a humidity standpoint.
Kai 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 Kai ranges from 11°C (52°F) to 19°C (66°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 Kai, with a climate score of 3.6/10. Consider visiting during April, May, June, September, October instead for better conditions.
For July in Kai, pack Umbrella, Waterproof jacket, Waterproof shoes, Breathable clothing, Sunscreen (SPF 30+). With average highs of 29°C (85°F) and 19 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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