Hiroshima in September: weather, what to wear and what's on

Hiroshima weather in September

Averages for 1991–2020 at the JMA's Hiroshima station (4 m above sea level).

High

29.1°C (84°F)

Low

21.1°C (70°F)

Precipitation

162.7 mm

Wet days

8.5 days

Sunshine

167 hours

Highs fall 3.7°C from August and drop another 5.4°C into October.

That is 8.0°C above Hiroshima's yearly average high of 21.1°C.

Of our 14 places with temperature records, Hiroshima is the 5th warmest in September: level with Nagoya and 0.3°C warmer than Nara.

September is Hiroshima's 4th wettest month (162.7 mm).

Of our 15 places, Hiroshima has the 4th lowest precipitation in September: 12.4 mm less than Fukuoka and 3.7 mm more than Nara.

Rain of 1 mm or more falls on 8.5 days, and 10 mm or more on 4.6 days.

Rain of 30 mm or more in one day falls on 2.0 days, and 50 mm or more on 0.8 days.

12.8 days reach 30°C or more.

On 2.7 nights the low stays at 25°C or above.

The sun is out for 40% or more of the possible hours on 16.6 days, and 4.1 days have under 0.1 hours of sunshine.

By the JMA's cloud records, 1.9 days are clear and 12.1 are overcast.

On 15 September 2027 the sun rises at 5:53 and sets at 18:18 in Hiroshima, giving 12 hours 25 minutes of daylight (NAOJ).

Average temperature

24.7°C (76°F)

Humidity

68%

Days of 25°C or more

27.1 days

Early, mid and late September

By the last ten days of September the average high in Hiroshima is 3.7°C lower than in the first ten.

By ten-day totals, 1–10 September is the wettest (62.9 mm) and 11–20 September the driest (47.8 mm).

What to wear in Hiroshima in September

Warm: highs around 29.1°C

• Short sleeves or thin long sleeves, with a light layer for air-conditioning and evenings.
• Heat: 12.8 days reach 30°C or more. A hat, water and sunscreen.
• A folding umbrella: rain falls on 8.5 days.

Pack

• Folding umbrella
• Hat, sunscreen and a water bottle
• A light layer for air-conditioning

• Our clothing rules

Rainy season and typhoons

In an average September, 1.1 typhoons come within 300 km of the Chugoku region; across Japan, 3.3 come within 300 km and 1.0 make landfall (JMA, 1991–2020).

September records in Hiroshima

The extremes the JMA has measured in September at its Hiroshima station.

Hottest September day

37.4°C (99°F) on 4 September 2023 (records since 1879)

Coldest September night

8.6°C (47°F) on 29 September 1965 (records since 1879)

Wettest September day

339.6 mm on 11 September 1926 (records since 1879)

Holidays and crowds in September

National holidays in September 2027:

• Mon 20 September — Respect for the Aged Day
• Thu 23 September — Autumnal Equinox Day

• Sat 18 September to Mon 20 September: 3 days off in a row

In September 2025, hotels and inns across Hiroshima Prefecture were 66.5% full on average (6th busiest of 12 months). Foreign guests spent 176,890 nights there that month (Japan Tourism Agency). That compares with 67.8% in August and 72.4% in October.

• Japan in September: visitor numbers and busy travel days
• Holidays in September
• Silver Week

What's on in Hiroshima in September

Not held, or changed

Hiroshima Minato Yume Fireworks Festival. Held on 25 July in 2026, from 20:00 to 21:00, offshore of the Hiroshima Port 10,000-ton berth. The organizer plans to move it to the fourth Saturday of September from fiscal year 2027 (Reiwa 9), so check the date before you plan around it. It goes ahead in rain and is cancelled if a typhoon or similar stops it on the day.

Official page

Hiroshima before and after September

• Hiroshima in August
• Hiroshima in October
• All 12 months in Hiroshima

Other places in September

• All 15 places in September

Related items

• Hiroshima by month
• Japan in September
• Hiroshima in August
• Hiroshima in October