Summer in Yokohama feels warm, humid, and, honestly, a bit sticky. High humidity and plenty of seasonal rainfall keep things lively.
During the day, temperatures usually hit 27–31 °C (81–88 °F), so it’s definitely the hottest stretch of the year. Nights don’t offer much relief either, often staying above 22 °C (72 °F).
You’ll notice the air gets muggy, especially in July and August, when tropical air masses roll in. Rain comes often, sometimes with sudden downpours or a typhoon thrown into the mix.
Even with the rain, August stands out as the sunniest summer month, so you’ll get more clear skies than in June or July.
If you’re out exploring, you’ll feel the jump from hot, bright afternoons to heavy rain showers. This mix of sun, rain, and humidity shapes summer life in Yokohama and really affects how you plan your day.
Overview of Yokohama’s Summer Climate
Yokohama’s summers get hot and humid, thanks to its subtropical spot near the sea. Rainfall stays high, clouds hang around, and typhoons sometimes swing by, but sea breezes can take the edge off the heat.
Climate Classification
Yokohama sits in a humid subtropical climate (Cfa) according to the Köppen system. So, you’ll get hot, humid summers with plenty of rain.
Daytime highs in July and August hover between 29–31 °C (84–88 °F), and nights rarely dip below 22 °C (72 °F). Humidity usually stays above 70%, making the air feel even heavier.
Rain falls often, with totals hitting about 1,700 mm (67 in) per year. Summer brings a big chunk of that. June marks the peak of the rainy season, while September and October usually get the heaviest downpours from typhoons.
Compared to winter, sunshine is limited. You’ll see only 5–6 hours of sun a day in summer, but August is the brightest. The sea warms up to 24–27 °C (75–81 °F), so swimming along the coast is possible from July through September.
Location and Influences
Yokohama sits on Tokyo Bay in the Kanto region of Honshu, just south of Tokyo. The coast really shapes summer weather here. The nearby sea sends in moisture, fueling both humidity and rain.
Mountains to the west block some inland extremes, but summer winds from the Pacific bring in warm, moist air. These monsoon currents create muggy weather and frequent showers.
Typhoons from the Pacific sometimes reach the area between August and early October. Not every storm hits directly, but strong winds and heavy rain can still mess with travel and outdoor plans.
Because of all this, you’ll see summer days that flip between hot sun, sudden rain, and sticky evenings by the bay.
Average Summer Temperatures in Yokohama
Summer in Yokohama means hot days and rising humidity. Both daytime highs and nighttime lows climb steadily from June into August.
Nights don’t cool off much, so you’ll feel the warmth around the clock.
Typical Daytime and Nighttime Temperatures
Daytime highs usually land between 75°F (24°C) and 85°F (29°C). On the hottest days, you might see 87°F (31°C), but it rarely jumps past 93°F (34°C).
Nighttime lows stay mild, averaging 64°F (18°C) to 75°F (24°C). Evenings rarely dip below 59°F (15°C), so nights feel warm and humid, especially in late July and August.
Since nights don’t cool down much, summer heat feels more persistent than in spring or autumn. You’ll want lightweight clothes and air conditioning for comfort.
Monthly Temperature Trends
Monthly averages show a clear seasonal shift.
- June: Highs around 75°F (24°C), lows near 64°F (18°C).
- July: Highs climb to about 82°F (28°C), lows around 71°F (22°C).
- August: Highs peak near 85°F (29°C), lows close to 75°F (24°C).
Early August typically brings the hottest stretch, with both daytime and nighttime temperatures at their highest. By late August, things start to cool down a bit, but the humidity sticks around.
So, July and August really bring the most intense heat and humidity of the year.
Comparison to Annual Averages
Yokohama’s annual average temperature sits around 59°F (15°C), so summer stands out as the warmest part of the year. Winter lows drop to the upper 30s °F (3–4°C), which is quite a difference.
Summer highs run about 20–25°F (11–14°C) above the yearly average. Nighttime lows in August even beat the average daytime high in spring.
This big gap explains why summer in Yokohama feels so long and muggy. You’ll spend months in temperatures far above the city’s usual climate, which really shapes the season’s character.
Precipitation Patterns During Summer
Yokohama’s summer comes packed with humidity and frequent rain, pushing totals well above the annual pace. Showers can show up out of nowhere, thanks to the East Asian monsoon and the occasional typhoon.
Rainfall Amounts by Month
Rain picks up fast in June. Expect around 150–200 mm of rain this month, which kicks off the monsoon season. Showers can be heavy, but they don’t always last long.
July keeps the totals high, averaging 120–160 mm. Rainy days are common, though downpours might not be as intense as in June.
August usually sees a small drop, with about 100–140 mm. Even with less rain overall, sudden storms and typhoons can still boost the numbers.
For context, Yokohama’s annual precipitation averages about 1,500 mm, so nearly a third of the yearly rain can fall just in summer.
| Month | Average Rainfall (mm) | Notes |
|---|---|---|
| June | 150–200 | Start of monsoon season |
| July | 120–160 | Humid, frequent showers |
| August | 100–140 | Lower totals, typhoon risk |
Rainy Days and Seasonal Variations
Rainy days matter as much as totals. In June, you’ll get 12–15 days with measurable rain, usually tied to the monsoon front.
July brings 12–14 rainy days. Showers often hit in the afternoon or evening, and the humidity makes even short rain feel heavy.
August averages 9–12 rainy days, but typhoons can suddenly bump that up. One storm can bring days of steady rain.
Winter sometimes has fewer than 6 rainy days a month, so summer clearly wins the “wettest period” award. Outdoor plans in June and July need flexibility.
You’ll notice longer dry breaks in August, though intense storms can still pop up. Late summer gets a bit easier to plan for, but the heat and humidity don’t really let up.
Humidity and Comfort Levels
Yokohama’s summer humidity can make warm days feel even hotter. Moist air from the Pacific shapes how you feel, and the heat plus dampness means you’ll probably tweak your routine.
Average Humidity in Summer
Humidity jumps from June through August. You’ll see 75–85% relative humidity most of the time. June starts around 77%, and July and August push things higher.
The East Asian monsoon brings in moist ocean air, making rain frequent, especially in June and July. Even on dry days, the air feels damp.
With average temperatures between 25°C and 30°C (77°F–86°F) and high humidity, the air gets heavy. The heat index runs higher than the thermometer, so evenings might not feel much cooler than afternoons.
Effects on Daily Life
High humidity really shapes your day. Walking outside for long stretches can feel exhausting, and sweat doesn’t evaporate quickly, so it’s harder for your body to cool down.
Most homes, hotels, and public spots have air conditioning, which is a lifesaver. Carrying a small towel or hand fan helps with the sticky feeling.
You can still enjoy outdoor sightseeing, but you’ll want to pace yourself. Locals often run errands early or late, when the air feels a bit less oppressive. Staying hydrated and wearing light, breathable clothes makes a big difference.
Wind and Other Weather Factors
Summer in Yokohama brings steady winds and humidity that shape each day. Tropical systems passing near Japan can also shake up the weather, affecting rain, wind, and travel.
Typical Wind Speeds and Directions
You’ll usually feel light to moderate winds in summer, with speeds between 7 to 12 km/h (4 to 7 mph). These breezes help a little with the heat but don’t do much to cool things down.
The wind mostly comes from the southeast, pulling in moist air from the Pacific. This keeps humidity high and days feeling sticky. On clear evenings, breezes from the bay can feel a bit cooler.
When weather fronts move in, wind patterns shift. High-pressure systems bring calmer, lighter breezes, while low-pressure systems can kick up the wind and signal rain.
So, expect steady humidity and only mild cooling from the wind. Light, breathable clothes are more useful than hoping for a strong breeze.
Storms and Typhoon Influence
From late summer into early autumn, typhoons become a risk. These storms bring stronger winds, heavy rain, and sometimes flooding. Even if a storm doesn’t hit directly, wind speeds can jump and the sea can get rough.
During a nearby typhoon, gusts can top 40–60 km/h (25–37 mph), even if the center stays far away. Strong winds can disrupt ferries, flights, or outdoor events.
Rain often gets heavier during these times. October usually sees the most rain, but late August and September can also get big downpours from tropical systems.
If you’re traveling, keep an eye on the forecast. Local advisories share updates on wind, storm paths, and safety tips. Most summer days stay calm, but tropical weather can flip things fast.
Sunshine and Daylight Hours in Summer
Summer in Yokohama means long days, with a mix of bright sun and stretches of cloud or rain. You’ll have steady daylight from early morning into early evening, but how much sun you actually get depends on the month.
Average Daily Sunshine
In Yokohama, summer sunshine feels moderate, not constant. You usually get 5.5 to 6.5 hours of direct sun per day from June through August.
June comes cloudier because of the rainy season, so you might only see about 4.5 to 5 hours of sun. August, on the other hand, is the brightest, with around 6.5 hours.
You’ll notice a mix of sunny breaks and cloudy intervals. Rain showers and humid air often cut down the clear skies, especially in June and early July.
By August, the weather calms down, and you get more reliable sunshine. Planning outdoor activities in August gives you the best shot at clear skies.
June? You’ll want to stay flexible, since the weather can flip pretty quickly.
| Month | Avg. Sunshine Hours/Day | Notes |
|---|---|---|
| June | 4.5–5 | Rainy season peak |
| July | 5.5 | Mix of sun and rain |
| August | 6.5 | Brightest month |
Length of Daylight
Daylight in Yokohama during summer stretches long, so you’ve got lots of time to get outside. In June, the sun rises around 5:15 AM and sets close to 6:55 PM.
That’s nearly 14 hours of daylight—the longest you’ll get all year.
By July, sunrise moves a little earlier, landing between 4:35 and 4:45 AM, with sunset still near 6:55 PM. The daylight stays close to 14 hours.
August brings shorter days. Sunrise comes around 5:00 AM and sunset drops to about 6:30 PM, leaving you with roughly 13.5 hours of light.
With these long days, you can explore the city even if the weather doesn’t always cooperate. Early mornings and evenings usually feel more pleasant, since the heat and humidity ease up a bit.
| Month | Sunrise (approx.) | Sunset (approx.) | Daylight Hours |
|---|---|---|---|
| June | 5:15 AM | 6:55 PM | ~14 hrs |
| July | 4:40 AM | 6:55 PM | ~14 hrs |
| August | 5:00 AM | 6:30 PM | ~13.5 hrs |
Tips for Experiencing Summer Weather in Yokohama
Summer in Yokohama brings high humidity, plenty of rain showers, and hot afternoons. You’ll have a better time if you plan your outings based on the weather and dress for the conditions.
Best Times for Outdoor Activities
Morning and evening usually feel best for being outside. Temperatures drop, and the humidity doesn’t seem as stifling as it does midday.
If you want to walk along the waterfront or wander through parks, try heading out before 10 a.m. or after 6 p.m.
Rain falls often in June and July. September can also bring heavy showers, thanks to typhoons.
August is hot, but you’ll see fewer rainy days and more sun. It’s a popular month for festivals and fireworks, though you’ll need to deal with the heat.
If you’re planning to visit places like Sankeien Garden or Yamashita Park, check the forecast first. Sudden, heavy rain can ruin your plans, so keeping things flexible helps.
Indoor spots like museums or shopping centers make great backups when storms roll in during the afternoon.
What to Pack for Summer Visits
Go for light, breathable clothing if you want to survive both heat and humidity. Cotton and linen? They’re honestly the best options.
I always toss in a small towel or handkerchief. You’ll probably need it, since sweating in that muggy air happens fast.
Don’t forget an umbrella—those sudden showers sneak up on you. If you’d rather keep your hands free, a compact rain jacket does the trick.
Streets get wet and weirdly slippery, so I usually wear comfortable shoes that dry quickly. It’s just less hassle.
Definitely pack sunscreen, sunglasses, and a hat for those brutal sunny stretches. Bring a reusable water bottle too.
Sure, convenience stores are everywhere, but carrying your own water just feels smarter when you’re out for a while.