Hiroshima weather in September

September in Hiroshima: hot, soaked, with clean air — a gamble, with 15 rainy days.

Updated September 2026 · climate normals from ERA5 reanalysis

Hiroshima🇯🇵 Japan · Mainland Japan · City63
  1. 67Jan
  2. 70Feb
  3. 74Mar
  4. 81Apr
  5. 86May
  6. 68Jun
  7. 53Jul
  8. 56Aug
  9. 63Sep
  10. 87Oct
  11. 83Nov
  12. 71Dec

#10 of 12 months in Hiroshima · #1077 of 1413 destinations to visit in September · comfort 63/100 (tier C)

Days
30°C
Nights
22°C
Wet days
15
Sun
8.1 h
Humidity
82%
Daylight
12 h
Hiroshima, Japan
Photo: David Warner · Pexels

Traveller notes on Hiroshima in September

Other months in Hiroshima

Regulars are consistent that snow itself is genuinely unlikely here, even in the back half of the month, but the cold still arrives regardless - the standard advice is to pack properly warm layers rather than count on a mild version of the month. Our row backs that cool, still-snow-light read, 12.3C over 4.2C nights feeling 1C, with 58.7mm of rain across 9.6 days and a trace of snow, 4.2cm, matching regulars' sense that it happens but isn't the norm. Regulars are specific this month runs a degree or two colder at night than nearby Osaka, worth noting for anyone comparing the two on the same itinerary. The sea sits at a cool 15C. The record: humidity 75 percent, 6.9 hours of sun, a 14.2 kph wind and AQI 44.
SnowUnlikelyButBringWarmClothesAnyway · December · 1 month ago · Read more on Tripadvisor ↗
Asked whether mid-March is busy for the blossom here, regulars answer that it is too early even this far south - the city usually peaks in the first week of April, and the island across the water, being warmer, runs slightly ahead of it. March is still winter weather: our row reads 15.7C by day feeling 13C, 6.2C nights feeling 4C, with 113.7mm of rain across 11.5 days and 1.8cm still in the snow column. The blossom date moves with the season's warmth and a storm at peak can end it early, so the year's forecast is the only planning tool. The record: humidity 73 percent, 8.5 hours of sun, an 11.6C sea and AQI 62.
TooEarlyForSakuraEvenHere · March · 1 month ago · Read more on Tripadvisor ↗
Regulars aiming at the Miyajima colour name a five-day window, the 13th to the 17th of November, while saying outright that nobody can predict the peak - one visitor on the 24th found it well past. Autumn is the island's busiest season for exactly this reason, and they suggest staying overnight rather than day-tripping. On weather they are warm about the month: often sunny, dry and crisp, with a light jacket wanted on the ferry and at the end of the day. Our row agrees at 18.6C days over 9.5C nights feeling like 7C, with 60.3mm across only 6.5 days. The record: humidity 77 percent, 7.9 hours of sun, a 19.4C sea and AQI 41.
TheThirteenthToTheSeventeenth · November · 1 month ago · Read more on Tripadvisor ↗
May in Hiroshima sits in the gap between Golden Week and the rains: the tsuyu does not reach cities like this one until about 7 to 10 June, and the weeks from around 10 May onwards are the ones regulars name as the best of the year. Warm to hot, and changeable - their description is three days of sun then a day or two of rain, with late May delivering some perfect days, a few hot and humid ones and one or more wet. Our row carries 147.8mm across 9.6 precipitation days, which is heavy rain concentrated rather than constant drizzle. Pack across the range: short sleeves to light jacket, waterproof shoes and a folding umbrella. The record: 24.6C days that feel like 26C, 15.5C nights and an 18.4C sea.
AfterGoldenWeekBeforeTheRains · May · 1 month ago · Read more on Tripadvisor ↗

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Hiroshima climate normals — September

Daytime high30°C / 85°F🥵 hot
Nighttime low22°C / 72°F
Feels like (high)33°C / 91°F
Sea temperature28°C / 83°F♨️ bath-warm
Rainfall221 mm / 8.7 in⛈ soaked
Rainy days15 days
Humidity82%💦 very humid
Dew point18°C / 64°F
Sunshine8.1 h/day
Daylight12.4 h
Wind12 km/h / 7 mph
Air quality (US AQI)43🍃 good

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in Hiroshima in September

How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.

Quietschool holidays in 3 of the markets that fill it, one of its worst months for weather(estimated)

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Peak crowdsBusyShoulder seasonQuiet

Best months for Hiroshima's weather

Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).

Toughest weatherHiroshima's best weather comes in May, October and November — separate windows, not one continuous season.

September coincides with Typhoon season.

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Best weatherFair weatherToughest weather

What's on in Hiroshima in September

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Rule

    Miyajima visitor tax

    1 Jan – 31 Dec

    A hundred yen per visit to the island, collected with the ferry ticket since October 2023. Rail-pass holders buy it separately at the terminal; a year pass is five hundred. Source ↗

  • Hazard

    Typhoon season

    1 Aug – 30 Sep · usuallyClosures

    The Inland Sea is sheltered compared with the Pacific coast, but a system tracking through stops the Miyajima ferry and the shinkansen for a day. Source ↗

What's on around the world in September →

Nearby, and something's on

Within 300 km of Hiroshima — a day trip or a short hop — with something on this month. Never part of the comfort score.

Where is Hiroshima?

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Hiroshima in September — FAQ

Is September a good time to visit Hiroshima?
September in Hiroshima: hot, soaked, with clean air — a gamble, with 15 rainy days. It ranks #10 of 12 months for Hiroshima on SeasonMap's comfort score (63/100).
What is the weather like in Hiroshima in September?
In September, Hiroshima averages a daily high of 29.5°C and a low of 22.1°C, with about 220.9 mm of rain over roughly 14.8 rainy days.
What is the air quality in Hiroshima in September?
Hiroshima has a mean US Air Quality Index of about 43 in September.

Within 300 km: Osaka's Kishiwada Danjiri Matsuri on 18–20 Sep.