Summer in Tokyo is a wild ride of heat, humidity, and those sudden rain showers that seem to catch everyone off guard. Most days, you’ll find yourself slogging through muggy air with highs easily soaring past 30 °C (86 °F). Nights don’t really cool off much, either, so the heat just kind of hangs around, making the season feel a bit relentless compared to the milder months.
The skies? They don’t like to stay the same for long. One minute there’s blazing sunshine, the next, you’re watching a wall of rain sweep through. June kicks off the rainy season. By July and August, it’s hotter and sunnier, but those short, intense downpours still show up. Sometimes, typhoons roll in late in the summer, bringing wild winds and buckets of rain.
On the bright side, summer gives you some of the longest days of the year. You get early sunrises and those long, drawn-out evenings, which means more time to wander Tokyo’s neighborhoods, parks, or maybe stumble into a festival or two. It’s a tough season, but honestly, it’s also when the city feels most alive.
Overview of Summer in Tokyo
Tokyo’s summer hits hard with high heat, plenty of humidity, and frequent rain. You get long days, strong sun, and the looming chance of typhoons, so daily life and travel get a bit unpredictable.
When Summer Begins and Ends
In Tokyo, summer usually kicks off in June and sticks around until September. Early June means the start of tsuyu, or rainy season, which can drag on for a few weeks. You’ll see steady showers and gray skies before the real summer heat cranks up.
By late June or early July, the weather flips to hot and sticky. July and August are the heavy hitters, with average highs between 30–32 °C (86–90 °F). Nights stay warm, often above 24 °C (75 °F), so if you don’t have air conditioning, sleeping gets tricky.
Things finally ease up in September, but honestly, the heat can linger. September also brings a higher risk of typhoons, so you might get slammed with strong winds and heavy rain. As the month goes on, you’ll notice the first hints of autumn, but the weather can still be all over the place.
General Characteristics of the Season
Tokyo’s summer is all about high humidity and frequent rain. Average daily highs bounce between 25–35 °C (77–95 °F), and sometimes a heat wave will push things even higher. Humidity often creeps past 70%, making the outdoors feel sticky and heavy.
Rain is a big part of the picture, especially in June and September, when totals often top 150 mm per month. You’ll get thunderstorms on hot afternoons, and typhoons can dump a ton of rain in a hurry. Still, when the sun comes out, it’s strong, and UV levels are no joke.
If you’re thinking about swimming, the sea in Tokyo Bay warms up to 23–26 °C (73–79 °F). But keep in mind, the city’s heat and humidity, plus all the concrete, crank up the heat island effect. That means Tokyo stays warmer than the countryside nearby.
How Summer Compares to Other Seasons
Summer in Tokyo feels like the polar opposite of winter, which is dry and mild, with highs around 10 °C (50 °F). Humidity and heat make even simple outdoor activities more draining, while winter days are crisp and way more comfortable for walking around.
Spring and autumn are the sweet spots, with highs between 15–23 °C (59–73 °F). There’s more sunshine, less humidity, and the city looks its best with cherry blossoms or autumn leaves. No wonder those seasons are travel favorites.
Rainfall tells a different story. Winter barely gets any, while summer and early autumn see the most. Typhoons? Only summer has to deal with those, adding a dose of unpredictability you just don’t get in other seasons.
Average Summer Temperatures
Tokyo’s summer brings the heat—hot, humid, and steadily warming from June through August. Both daytime highs and nighttime lows climb quickly, and the city’s humidity just makes everything feel even warmer.
Typical Daytime and Nighttime Temperatures
Daytime highs in Tokyo during summer usually start at 75°F (24°C) in June and creep up to about 85°F (29°C) in August. On the hottest days, you might see 93°F (34°C).
Nights get warmer too. In June, evenings average around 64°F (18°C), but by August, they’re closer to 74°F (23°C). It’s rare to get a cool night, so without AC, sleeping can be a struggle.
Humidity just piles on. Even if the thermometer says it’s in the upper 70s, the moisture in the air makes it feel hotter. Expect muggy nights, especially in late July and August.
Monthly Temperature Trends
Watch how the numbers shift from early to late summer.
- June: Highs around 75°F (24°C), lows about 64°F (18°C).
- July: Highs climb to 82°F (28°C), lows hover near 70°F (21°C).
- August: The peak, with highs at 85–87°F (29–31°C) and lows around 74°F (23°C).
The hottest spell usually lands in early August, when both day and night temperatures hit their max. By late August, things start to cool off a bit, though the humidity usually sticks around.
This steady temperature climb makes July and August the toughest months for being outside, while June, despite more rain, feels a bit more manageable.
Record Highs and Lows
Tokyo doesn’t see the wildest extremes, but it still gets some serious heat. The hottest daily average high is about 87°F (31°C), usually in early August, and some days can spike past 95°F (35°C) during a heatwave.
Nights don’t cool much, either. Even in June, it rarely drops below 59°F (15°C). By August, it’s not unusual for lows to stay above 77°F (25°C), so evenings stay sticky.
Tokyo’s spot by the coast keeps things from getting too wild, but the combo of heat and humidity can still get to you, especially in August when muggy nights are the norm.
Humidity and Heat Index
Tokyo’s summer is basically a lesson in humidity. The air gets thick, the heat index climbs, and suddenly, it feels way hotter than what the thermometer says.
Average Humidity Levels
From June through August, average relative humidity stays between 80% and 93%. June starts out sticky, often above 85%. July peaks around 93%, and August only drops a little, to about 90%.
All this moisture makes the air feel heavy. Sweat doesn’t evaporate fast, so your body has to work harder to cool off.
Compare that to winter, when humidity can dip to 50%—the difference is huge. If you’re used to drier places, Tokyo’s summer air might feel like a wall.
Perceived Temperature and Discomfort
The heat index is what really tells the story. Say it’s 34°C (93°F) with humidity over 85%—it’ll feel more like 42°C (108°F).
That’s why Tokyo’s summer can feel so much hotter than the numbers suggest. Your body struggles to get rid of heat, so you tire out faster, and being outside gets tough.
Short walks might be fine, but longer stretches in the sun get uncomfortable fast. Even at night, temperatures stay above 25°C (77°F), and the air doesn’t really dry out.
Tips for Coping with Humidity
There are ways to make it easier on yourself. Try these:
- Clothing: Lightweight, breathable stuff like cotton or linen helps.
- Hydration: Drink water often, even before you feel thirsty.
- Timing: Get outside in the morning or evening when it’s cooler.
- Shelter: Duck into shaded spots, air-conditioned cafés, or malls for a break.
- Accessories: A small towel, handheld fan, or cooling wipes can be lifesavers.
If you’re sensitive to heat, avoid the outdoors at midday. Luckily, Tokyo’s public transport and most indoor spots crank the AC, so there’s always somewhere to escape the muggy air.
Rainfall and Precipitation Patterns
Tokyo’s summer means steady rain, thick humidity, and those sudden showers that seem to pop up out of nowhere. From June through September, you’ll spot some clear trends.
Monthly Rainfall Amounts
The East Asian monsoon and typhoons shape Tokyo’s summer rain. June usually brings in 160–180 mm. July averages 130–150 mm, and August clocks in at 150–170 mm.
September really stands out, often hitting 200 mm or more. That’s usually thanks to typhoons, which can dump a ton of rain in a short time.
For some perspective, winter months like December barely get 70 mm. So, summer’s a big jump, and the warmer air just makes everything feel heavier.
Frequency of Wet Days
Rain isn’t just about totals—it’s about how often you get wet. June sees 12–14 rainy days. July and August usually have 10–12 days with measurable rain. September picks up again, with 13–15 wet days.
Most of these aren’t washouts. You’ll get passing showers or a quick thunderstorm, often in the late afternoon. That leaves mornings open for outdoor plans, as long as you’re flexible.
Winter is a different story, with only 5–6 days of rain in January. Summer’s pattern is way wetter, so keep an umbrella or light rain jacket handy for those surprise showers.
Notable Rain Events
Two main weather patterns drive the rain. First up is the Baiu front, a seasonal rain band that hangs around from early June to mid-July. It brings cloudy skies and steady showers.
Then there’s typhoon season, peaking in late August and September. Typhoons can drop heavy rain fast—sometimes more than 100 mm in a day. Even if the storm doesn’t hit directly, the outer bands often reach Tokyo.
That’s why September can be so rainy. And it’s also why summer travel plans sometimes need a backup—delays and sudden changes are just part of the deal.
Sunshine and Daylight Hours
Summer in Tokyo stretches the days out, giving you loads of daylight. But the actual sunshine varies a lot. Cloud cover, rain, and the summer monsoon often cut down on the number of truly clear hours, even when the days are long.
Average Daily Sunshine
In Tokyo’s summer, you’ll usually get somewhere between 5 to 6.5 hours of sunshine per day. June brings the least, with about 5 hours daily—the rainy season really cuts into the sun.
July and August look brighter, and August averages about 6 hours and 30 minutes of sunshine each day.
Even though daylight lasts long, sunshine still only takes up about 40–50% of daylight hours in summer. The rest of the time, clouds or haze dominate the sky.
So, even without rain, outdoor plans might still feel damp and overcast.
Here’s a quick look at average daily sunshine hours:
| Month | Avg. Sunshine Hours/Day | % of Daylight Sunny |
|---|---|---|
| June | 4h 58m | 35% |
| July | 5h 50m | 41% |
| August | 6h 34m | 49% |
Length of Daylight
June gives Tokyo the longest days, with about 14 hours and 30 minutes of daylight near the solstice. July isn’t far behind, with around 14 hours and 18 minutes.
By August, daylight slips to about 13 hours and 30 minutes, but evenings still feel long.
Winter daylight drops below 10 hours, so summer feels like a treat for anyone who wants to be outside.
This extra daylight is great for sightseeing, day trips, or just wandering around after dinner, even if the sky’s a bit gray.
The difference between the longest and shortest days in Tokyo is about 4 hours and 50 minutes. That’s a pretty big swing and really changes the pace of daily life.
Sunrise and Sunset Times
In summer, the sun rises early and sets late, so you get long, usable days. June’s sunrise is around 4:25 AM, and sunset hits close to 7:00 PM.
July shifts a bit—sunrise at about 4:35 AM and sunset near 6:55 PM.
August brings later sunrises, around 4:55 AM, and sunsets earlier, near 6:30 PM. Evenings start to feel shorter as summer goes on.
If you’re planning outdoor stuff, mornings usually have the clearest skies. The middle of the day gets hot and sticky, and afternoons can bring clouds or quick showers.
So, timing really matters if you want good light for sightseeing or photos.
Cloud Cover and Sky Conditions
Tokyo’s summer sky flips between bright blue and heavy gray. One moment it’s sunny, and the next, clouds roll in, sometimes bringing sudden rain.
Typical Cloudiness
High humidity and moist Pacific air make Tokyo’s summer skies frequently cloudy. June and July overlap with the rainy season, so you’ll see a lot of gray, especially late June.
August gives you a few more sunny breaks, but haze and scattered clouds still stick around.
Most days, expect partly to mostly cloudy skies for much of the daylight.
Cloud cover changes how hot it feels. Thick clouds block direct sun, but the humidity keeps things muggy.
When the clouds finally part, the sun heats up the city fast, and it can get uncomfortable.
If you’re planning to be outside, just be ready for variable conditions and check the daily forecast.
Clear skies happen, but not as often as in spring or autumn.
Clear Versus Overcast Days
The mix of clear and cloudy days shifts as summer rolls on. June barely has any clear days because of the rain.
July brings more breaks in the clouds, but showers and storms still pop up.
August? That’s when you’ll see the most sun, though even then, full days of sunshine are rare compared to other places.
A typical summer day might start bright, cloud over by afternoon, and end with a surprise shower.
Here’s a quick way to see it:
- June: Mostly overcast
- July: Mixed skies
- August: Clearer, but still humid and unsettled
If you’re visiting, expect short sunny periods instead of endless blue skies. That’s just how Tokyo’s humid subtropical climate works.
Wind and Atmospheric Conditions
Tokyo’s summer feels heavy and damp, but wind and air pressure make a big difference in your day. Breezes from the ocean and shifts in pressure can change how comfortable the city feels and even how far you can see.
Prevailing Winds in Summer
Most summer winds in Tokyo come from the southeast, straight off the Pacific. These breezes carry warm, moist air that adds to the city’s muggy vibe.
You’ll usually feel light to moderate winds, about 5–15 km/h (3–9 mph).
Stronger gusts show up during storms or typhoons, especially from late August into September.
Because Tokyo’s packed with tall buildings, wind patterns change a lot at street level. Narrow lanes can funnel breezes, while open spots like Tokyo Bay feel more exposed.
So, depending on where you are, the wind can feel completely different.
For travelers, the steady ocean air keeps things sticky but stops the air from getting too dry.
Winds don’t usually cool you off much, but they help clear out pollution and keep air quality from getting too bad.
Air Pressure and Visibility
Summer in Tokyo usually brings low and unpredictable air pressure. The Pacific High, a seasonal pressure system, takes over much of East Asia during the warm months.
When the pressure drops, clouds roll in and rainfall picks up, so visibility tends to get worse.
On the rare clear days, you might catch a glimpse of Mount Fuji from some observation points. But honestly, humidity and urban air pollution often put a damper on those views.
This haze really stands out in the afternoon when moisture hangs in the air.
Most summer days, you’ll get 6–10 km of visibility, but rain or thick haze can cut that down below 5 km.
After a typhoon sweeps through and clears the air, visibility sometimes jumps to 20 km or more.
These conditions shape daily life, not just sightseeing.
Lower pressure can make the air feel heavy, and all that humidity shrinks your view.
If you’re hoping for outdoor plans, mornings usually give you the best chance for clear skies before haze creeps in later.