Hiroshima Weather Guide: Month-by-Month Climate, Best Season & What to Pack

Hiroshima's Climate: What the Seto Inland Sea Does to the Weather

Hiroshima city sits on the northern shore of the Seto Inland Sea (瀬戸内海), a semi-enclosed body of water that significantly moderates the climate. The result is milder winters and less extreme summers compared to cities on the open Pacific coast or the heavy-snowfall Sea of Japan coast.

According to Japan Meteorological Agency data (1991-2020 normals), Hiroshima has a humid subtropical climate with four distinct seasons: a mild spring with cherry blossoms, a hot and humid summer broken by rainy season (tsuyu / 梅雨), a comfortable autumn with foliage, and a cool winter that rarely sees snow in the city.

The Chugoku Mountains running through northern Hiroshima Prefecture create a weather divide. The city stays relatively dry while the mountains to the north receive heavy snowfall from December through March — a pattern that makes city sightseeing pleasant even in winter while enabling day-trip skiing from the same base.

Month-by-Month Climate Table

Based on JMA 1991-2020 normals for Hiroshima city:

Month	Avg High °C (°F)	Avg Low °C (°F)	Rainfall mm	Sunshine hrs	Notes
Jan	10 (50)	2 (36)	45	145	Cold, dry, rare snow
Feb	11 (52)	2 (36)	65	145	Cool, plum blossoms
Mar	14 (57)	5 (41)	115	170	Warming, cherry blossoms late month
Apr	20 (68)	10 (50)	130	190	Peak cherry blossoms, mild
May	25 (77)	15 (59)	140	210	Best sunshine, warm
Jun	27 (81)	19 (66)	240	145	Tsuyu begins (~Jun 7)
Jul	31 (88)	24 (75)	260	170	Tsuyu ends (~Jul 20), hot
Aug	33 (91)	25 (77)	110	210	Peak heat, typhoon risk
Sep	29 (84)	21 (70)	170	170	Typhoon risk, cooling
Oct	23 (73)	14 (57)	90	190	Comfortable, clear
Nov	17 (63)	8 (46)	65	165	Autumn foliage
Dec	12 (54)	3 (37)	40	150	Cool, dry, quiet

Annual rainfall averages approximately 1,540 mm with the heaviest concentration in June-July (tsuyu). Annual sunshine totals approximately 2,033 hours — with May being the sunniest month at over 210 hours.

Best Time to Visit Hiroshima

Spring (March-May): Cherry Blossoms and Clear Skies

Spring is the most popular season for good reason. Late March to early April brings cherry blossoms (sakura / 桜) — Hiroshima's Peace Memorial Park and Shukkeien Garden are prime hanami spots. Temperatures are comfortable (14-25°C) and rainfall is moderate.

May is the sunniest month, with warm days and low humidity before tsuyu arrives. This is arguably Hiroshima's best single month for weather.

Autumn (October-November): Foliage and Comfortable Temperatures

Autumn is the second-best window. October brings clear skies and comfortable temperatures (14-23°C). November brings autumn foliage (koyo / 紅葉) — Miyajima's maples are particularly spectacular, with peak color usually around mid-November.

Rainfall drops sharply in October-November, making it reliable for outdoor sightseeing.

Summer and Winter: Trade-Offs

Summer (June-August): Tsuyu (rainy season) typically starts around June 7 and ends around July 20, based on JMA historical averages. After tsuyu, August brings intense heat — daily highs regularly exceed 33°C (91°F) with humidity making it feel hotter. Summer sightseeing is manageable with early morning starts and air-conditioned rest stops, but extended outdoor time is uncomfortable.

Winter (December-February): Hiroshima's winters are mild by Japanese standards. January averages 10°C (50°F) during the day and 2°C (36°F) at night — cool but not harsh. Snow is rare in the city (about 7 days per year with minimal accumulation). Winter offers fewer crowds and lower hotel prices. For mountain snow conditions and nearby skiing, see our Hiroshima snow and winter guide.

Rainy Season and Typhoons: What to Expect

Tsuyu (June-July): Hiroshima's Rainy Season

Hiroshima's tsuyu (梅雨, literally "plum rain") typically runs from early June through mid to late July. According to JMA data, the average start is around June 7 and the average end is around July 20.

Tsuyu is not constant rain — it brings frequent showers interspersed with humid overcast days. June and July are the wettest months, each averaging 240-260 mm of rainfall. Many visitors on Reddit recommend packing lightweight rain gear rather than relying solely on umbrellas, as sudden downpours can be heavy.

Sightseeing during tsuyu is still possible. Indoor attractions (Peace Memorial Museum, Hiroshima Castle) are unaffected, and rain can add atmosphere to garden visits. Just plan flexible itineraries with indoor alternatives.

Typhoon Season (August-October): How It Affects Travel

According to JMA data, Hiroshima is affected by 2-3 typhoons per year on average, with activity peaking from August through October. Hiroshima is less exposed than Okinawa or the Pacific coast, but typhoons still bring heavy rain, strong winds, and transport disruptions.

The main impact for travelers: ferries to Miyajima may be cancelled during typhoons, and outdoor plans can be derailed for 1-2 days. Shinkansen services are occasionally delayed but rarely fully suspended. Check the JMA typhoon tracking app daily during this period.

What to Pack for Each Season

Spring and Autumn Packing

• Light layers: temperature swings 10-15°C between morning and afternoon
• One warm jacket for evenings (especially March and November)
• Comfortable walking shoes — Hiroshima is walkable
• Compact umbrella for spring showers

Summer Packing

• Lightweight, breathable clothing — cotton or moisture-wicking
• Compact rain jacket or poncho for tsuyu season
• Sun hat, sunscreen, portable fan
• Water bottle — hydration is essential above 30°C
• Indoor activities backup plan

Winter Packing

• Medium-weight jacket or warm coat — not heavy winter gear
• Waterproof shoes — occasional rain more likely than snow
• Scarf and light gloves for evening walks
• Layers for indoor-outdoor temperature contrast (heated buildings, cool outside)

For mountain day trips in winter, pack significantly warmer gear. The temperature difference between coast and mountains is substantial. See the Hiroshima snow and winter guide for details.

Frequently Asked Questions

What is the best month to visit Hiroshima?

Late March to April for cherry blossoms and mild weather, or November for autumn foliage. May offers the most sunshine (over 210 hours) with warm temperatures before rainy season. Avoid late June to mid-July (tsuyu rainy season) and mid-August (extreme heat and humidity) unless you have indoor-focused plans.

Does it snow in Hiroshima?

Rarely in the city — winters are mild with an average January high of 10°C (50°F). Hiroshima city sees about 7 snowfall days per year with only 12 cm total annual accumulation. The mountains of northern Hiroshima Prefecture receive heavy snowfall (100-200 cm annually) and have ski resorts. See our Hiroshima snow and winter guide for mountain snow and skiing details.

How bad are typhoons in Hiroshima?

Hiroshima is affected by 2-3 typhoons per year on average, peaking August through October. Less severe than Okinawa or the direct Pacific coast, but ferries to Miyajima may be cancelled and outdoor plans disrupted for 1-2 days. Check JMA typhoon forecasts daily during this period and have indoor alternatives ready.

Is summer too hot for sightseeing in Hiroshima?

August daily highs regularly exceed 33°C (91°F) with high humidity, making extended outdoor sightseeing challenging. Visit the Peace Memorial Park and Miyajima early morning or late afternoon. Indoor attractions (Peace Museum, Hiroshima Castle) and the Shinkansen are well air-conditioned. Summer is manageable with planning but not the most comfortable season.

When is rainy season in Hiroshima?

Tsuyu typically starts around June 7 and ends around July 20, based on JMA historical averages. It brings frequent showers and high humidity rather than constant rain. Pack lightweight rain gear, plan flexible itineraries with indoor alternatives, and expect some disruption to outdoor plans.