"Japan has four beautiful seasons" — you'll hear this often. But once you actually live here, "six seasons" feels closer to the truth.
Spring, rainy season, summer, autumn, winter, and pollen season — each one significantly shapes daily life. Without knowing this in advance, you'll struggle with clothing, health, and scheduling.
This guide walks through Japan's monthly weather, preparation for rainy season, typhoons, heatwaves, and hay fever, plus seasonal differences in clothing and utility costs — all from the perspective of foreign residents.
Monthly weather calendar (Tokyo as reference)
| Month | Average temp | Main weather |
|---|---|---|
| January | 5°C | Coldest month; very dry |
| February | 6°C | Late peak cold; pollen begins |
| March | 9°C | Pollen peak; cherry blossoms bloom |
| April | 14°C | Full spring; mild |
| May | 19°C | Early summer; pleasant |
| June | 22°C | Rainy season starts (around June 7 average) |
| July | 26°C | Rainy season ends (mid-to-late month); heat begins |
| August | 28°C | Brutal heat; typhoon season |
| September | 24°C | Lingering heat; typhoon peak |
| October | 19°C | Full autumn; pleasant |
| November | 13°C | Fall foliage; sudden cold |
| December | 8°C | Early winter; very dry |
Average temperatures are JMA's "normal values" (1991–2020).
Spring (March–May) — beautiful, but don't let your guard down
The good: cherry blossom season, rising temperatures make outings easier
Watch out for:
- Day-to-night temperature swings of 10–15°C. Always carry a light outer layer.
- Hay fever (kafunshō): peak February–April (more below)
- Yellow sand (kōsa) carried from mainland China — visibility hazes, and on bad days you shouldn't hang laundry outside
- Haru ichiban: the first strong southerly wind of spring (February–March)
Cherry blossom season is short
From bloom to scattering takes about a week. Bloom forecasts come out in March from various weather services — plan ahead.
Tsuyu (June to mid-July) — "the fifth season"
"Tsuyu" is Japan's distinctive rainy season — about 40 days of continuous rain. For 2026, the Kanto rainy season is forecast to start around June 7 (typical timing).
| Region | Average start | Average end |
|---|---|---|
| Okinawa | Around May 10 | Around June 21 |
| Southern Kyushu | Around May 30 | Around July 15 |
| Kanto / Koshin | Around June 7 | Around July 19 |
| Southern Tohoku | Around June 12 | Around July 24 |
| Hokkaido | No rainy season | — |
Hokkaido essentially has no rainy season — by the time the rain front reaches that far north, it has weakened.
How to handle tsuyu
- Folding umbrella in your bag every day
- Rain boots or shoes treated with waterproof spray
- Dehumidifier or your AC's "dry" mode to manage room humidity
- Dry laundry indoors: Outside won't dry. Use indoor-drying detergent and a dehumidifier
- Anti-mold: Ventilate and use desiccants in the bathroom, closets, and around windows
- Watch for food poisoning: High temperature and humidity favor bacteria
Sudden downpours (guerrilla rain)
Even after rainy season ends, summer brings frequent guerrilla rain (sudden, intense localized thunderstorms). When the sky darkens abruptly, take shelter immediately. The JMA's "rain cloud radar" app helps predict approaching systems.
Summer (July–September) — battling extreme heat
Recent Japanese summers regularly set records — days over 35°C, called "mōsho-bi" (extreme heat days). Even Tokyo can approach 40°C.
Heatstroke prevention
Heatstroke (netchūshō) kills people every year in Japan. The elderly and young children are at the highest risk.
- AC: Use it without hesitation (your life is more important than the bill)
- Hydration: Drink before you feel thirsty. Combine water with salt (oral rehydration solution, salt tablets)
- Pick your outdoor times: 10:00–16:00 is especially dangerous
- "Heatstroke Warning Alert": Issued by the JMA — check on TV or your phone
Clothing
- Quick-dry, cooling-touch fabrics (Uniqlo's AIRism, MUJI lines, etc.)
- Parasol — recommended for all genders (men's parasols are increasingly common)
- Hats with wide brims
- Cooling gear: neck coolers, ice-pack vests
Typhoon season
August through October is typhoon season, peaking in September. 20–30 typhoons form annually, with 5–10 approaching or making landfall in Japan.
When a typhoon is coming
- 48 hours before approach: Check food, water, flashlight, and mobile battery
- 24 hours before: Move balcony items inside; tape over windows
- During approach: Don't go out, prepare for blackouts, expect "planned suspensions" of trains
- After it passes: Watch for fallen signs and downed power lines
"Planned suspensions" (keikaku unkyū) are announced by railways the day before — trains stop on the day of approach. Don't try to force your way to work.
Autumn (October–November) — the most pleasant time of year
The good:
- Mild temperatures (15–25°C)
- Humidity drops
- Fall foliage season (Kyoto, Nikko, and Hakone are famous)
- Delicious foods: pacific saury, mushrooms, chestnuts, persimmons, new-harvest rice
Watch out for: late-season typhoons (October) and the sudden cold snap in late November.
Winter (December–February) — dryness and cold
Tokyo winters are relatively mild in temperature (5–10°C), but extremely dry.
Coping with dryness
- Humidifier: Keep room humidity at 50–60%
- Moisturizer and lip balm: Protect skin and lips
- Mask: Combats dryness, prevents colds and flu
- Gargling and hand-washing: Make it a habit when arriving home
Heating
- Air conditioner: Most common (also handles cooling)
- Kotatsu: A Japanese-style heated table with a blanket; warms your legs
- Hot carpet: A floor-heating substitute
- Yutampo: A hot water bottle for the bedroom; saves on electricity
Snow
- Tokyo: Snow falls a few times per year, accumulation is rare (a few cm once every few years)
- Snow country (Niigata, Tohoku, Hokkaido): Heavy accumulation, snow shoveling is essential
- Transportation impact: In greater Tokyo, even a few centimeters can cause major train and bus delays
Studless tires
If you're heading to snow country or ski resorts, switch to studless tires by December. Even in greater Tokyo, avoid driving on snow-forecast days.
Hay fever — Japan's national affliction
Roughly 40% of Japanese people have hay fever (kafunshō), and many foreign residents develop symptoms after living here for several years.
Main causes and seasons
| Pollen | Season | Peak |
|---|---|---|
| Cedar (sugi) | Late January to April | Early-to-mid March |
| Cypress (hinoki) | March to May | April |
| Birch (Hokkaido) | April to June | May |
| Grass family | May to October | June, September |
| Ragweed | August to October | September |
Symptoms
- Sneezing
- Runny / stuffy nose
- Itchy / watery eyes
- Itchy throat
- Headache, fatigue
Prevention and treatment
- Mask: pollen-grade (non-woven, disposable)
- Glasses: pollen-blocking goggle styles
- Medication: over-the-counter (Allegion, Allegra, etc.) or prescription
- Don't dry laundry outside
- Brush off your clothes outside the entrance when you get home
- See a doctor: First-timers should consult an ENT (jibiinkōka) or allergist
Early treatment works
"Early-stage therapy" — taking medication starting two weeks before symptoms begin — is effective. Visiting a doctor in late January or early February is recommended.
Seasonal clothing calendar
| Month | What to wear |
|---|---|
| Jan–Feb | Coat + sweater + thermal underwear + scarf + gloves |
| March | Coat + light sweater (morning/night) / cardigan (day) |
| April | Cardigan + long-sleeve shirt |
| May | Long-sleeve shirt + light outer layer |
| June | Long sleeves + raincoat / light short sleeves |
| Jul–Aug | Short sleeves + sun protection + light layer for indoor AC |
| September | Short sleeves → long sleeves (residual heat by day, cool by night) |
| October | Long sleeves + light cardigan |
| November | Light coat + sweater |
| December | Coat + sweater + scarf |
Seasonal utility cost differences
Household utilities peak in summer and winter (single-person, Tokyo).
| Season | Monthly estimate | Peak driver |
|---|---|---|
| Spring (Apr–May) | ¥8,000–10,000 | Mild |
| Summer (Jul–Sep) | ¥12,000–15,000 | AC |
| Autumn (Oct–Nov) | ¥8,000–10,000 | Mild |
| Winter (Dec–Mar) | ¥13,000–18,000 | Heating + hot water |
Gas peaks in winter (bath, heating); electricity peaks in both summer and winter. For more, see "The Real Cost of Living in Japan".
FAQ
Q. How can I make tsuyu more comfortable?
A. Buying a single dehumidifier changes life dramatically (laundry dries in half the time, less mold). Combine that with two folding umbrellas (one in your bag, one at home) and you'll be much more comfortable.
Q. How do I tell my workplace I can't come in due to a typhoon?
A. When railways announce "planned suspensions" the night before or morning of, work-attendance expectations are usually relaxed. Contact your supervisor early: "Can I work from home?" or "I'll come in once service is restored."
Q. I'm worried about AC electricity costs.
A. The Ministry of the Environment recommends 28°C for cooling and 20°C for heating. Reducing the gap with outside temperature, plus using a fan to circulate air, is most efficient. Leaving it on is often cheaper than turning it on and off repeatedly.
Q. Should I go out when it snows?
A. In greater Tokyo, when more than a few centimeters are expected, avoid non-essential outings. Slips and broken bones happen every year. Wear non-slip sneakers or boots, and walk like a penguin (small steps, weight directly above your feet).
Q. Can I buy hay fever medication over the counter?
A. Yes — drugstores sell many options (Allegion 20, Allegra FX, Zaditen AL, etc.). For severe symptoms, prescription medication (cheaper with insurance) is often more effective.
Q. It's my first summer in Japan. What should I buy first?
A. Priority order:
- Air conditioner (if not built in)
- Electric fan or circulator
- Cooling pillow or cooling sheets
- Oral rehydration solution (such as OS-1)
- Insect repellent spray (mosquito protection)
Q. How do I enjoy hanami and koyo?
A. Hanami (cherry blossom viewing) is March–April; momijigari (autumn foliage hunting) is October–November (varies by region). "Hanami walks" — strolling without trying to claim a spot — are also popular. We'll cover this in detail in a separate article.
Q. What do I do during thunder and lightning?
A. Take shelter in a building or car, and stay away from windows, electronics, and water. If outside, avoid tall trees and utility poles, and crouch low. Unplug computers and appliances to prevent damage.
Final thoughts
Japan's climate combines "rich" and "harsh." Things to do today:
- Install JMA's app, plus "Yahoo! Weather" and "tenki.jp" on your phone
- Enable notifications for heatstroke alerts, typhoon updates, and heavy rain warnings
- Add one seasonal preparation item per month (dehumidifier, humidifier, folding umbrella, mobile battery, flashlight)
If you treat the seasons as something to prepare for rather than fight, Japan's climate reveals a different beautiful face every month.
At Nihongo-tomo, we offer free vocabulary lists for weather, clothing, and seasonal food. Learning words like "mōsho-bi" (extreme heat day), "netchūshō" (heatstroke), and "kafunshō" (hay fever) makes daily forecasts much easier to follow.
References / 参考・出典
- JMA — Past Tsuyu Start and End Dates — Normal values and quick reports
- JMA — Tsuyu Start and End for Reiwa 8
- JMA — Normal Values (1991–2020) — Average temperatures
- JMA — Protecting Yourself from Heatstroke / Heatstroke Warning Alert
- Ministry of the Environment — Hay Fever Environmental Health Manual
- tenki.jp — 2026 Tsuyu Start Forecast
- JMA — Typhoon Information
- JMA — Rain Cloud Movement (High-Resolution Precipitation Nowcast) — Guerrilla rain forecasting
All figures in this article are based on JMA normal values and forecasts as of May 2026. Weather varies year to year — check JMA's official site for the latest information.