WEATHERblaze

Hiroshima Historical Weather Data & Climate

Historical Climate Data for 20 Cities
•
1981–2025
•
Japan
⛅

Quick Climate Facts

(1981 – 2025)
Hottest City
🔥
Sera
Jul High 28.8°C
Coldest City
❄️
Shōbara
Jan Low -2.4°C
Wettest City
🌧
Etajima
1534 mm/yr
Driest City
🏜️
Sera
1458 mm/yr
Hottest Month
🌡
August
Avg 26.1°C
High 29.9°C
Coldest Month
🧊
January
Avg 3.2°C
Low -0.3°C
Cities With Data
🏙️
20
cities in Hiroshima
Data Coverage
📅
45 yrs
1981 – 2025

Hiroshima Climate Overview

Hiroshima has a warm temperate climate with warm summers and cold winters.

Hiroshima has an average annual temperature of 14.2°C across all 20 cities, with approximately 1497 mm of annual precipitation and average humidity of 81%. Temperatures peak in August and drop to their lowest in January, while rainfall is highest during summer months.

The warmest city is Sera with average July highs of 28.8°C, while Shōbara is the coldest with average January lows of -2.4°C. Humidity remains high throughout the year creating cold and damp conditions. These seasonal patterns make summer pleasant for travel, while winters can bring frost and occasional snowfall.

🏙️ Cities in Hiroshima — Weather History

📊 Hiroshima Monthly Climate Data

Monthly Climate Data
Month🌤️Avg HighAvg TempAvg LowRecord HighRecord LowHumid %Rain (mm)Wind (m/s)Solar (kWh/m²)
January🌤️6.7°C3.2°C-0.3°C19.7°C-9.0°C81%612.92.20
February🌤️7.9°C3.9°C-0.2°C18.8°C-11.2°C80%712.92.90
March⛅12.0°C7.1°C2.3°C22.7°C-6.5°C79%1102.83.80
April⛅17.4°C12.2°C7.0°C26.4°C-3.8°C78%1252.44.90
May⛅21.7°C16.8°C11.8°C31.4°C1.1°C78%1472.15.40
June🌧️25.2°C21.0°C16.7°C33.5°C6.7°C82%2171.94.90
July🌧️28.6°C25.0°C21.3°C37.2°C10.3°C85%2251.95.00
August⛅29.9°C26.1°C22.3°C38.0°C12.8°C82%1271.95.10
September🌧️26.4°C22.4°C18.5°C36.6°C5.6°C82%1722.24.10
October⛅20.8°C16.5°C12.1°C29.3°C0.9°C80%1022.33.50
November🌤️15.2°C10.9°C6.7°C26.3°C-3.1°C81%772.42.60
December🌤️9.4°C5.6°C1.7°C22.0°C-6.8°C82%632.72.00

Showing average climate conditions across 45 years (1981–2025) · averaged across all 20 cities in Hiroshima

🌦 Weather in Hiroshima Across Seasons

❄️ Winter in Hiroshima

January is Hiroshima's coldest month, with average lows reaching -0.3°C.
🌡️December to February (avg) · 0.4°C – 8.0°C

🧥 Expect frosty nights and below-freezing temperatures during this Cold Winter period.

☀️ Summer in Hiroshima

Summer temperatures in Hiroshima peak in August, climbing to 29.9°C.
🌡️July to September (avg) · 20.7°C – 28.3°C

🌤️ Conditions are ideal for outdoor activities throughout the day in this Mild Summer.

🌧️ Rainy Season in Hiroshima

Hiroshima sees its highest rainfall in July, receiving approximately 225 mm of precipitation.
🌧️June to September (avg) ·  up to 225 mm

☔ Heavy Rainfall expected — carry rain gear and plan outdoor activities around these months.

📈 Hiroshima Monthly Averages

🌡️ Temperature Patterns

Region-wide monthly averages across 20 cities · 1981–2025 · °C

🌡️ Hiroshima Monthly Temperature Guide

August is the hottest month in Hiroshima, with average highs reaching 29.9°C, while January is the coldest with lows dropping to -0.3°C.

Temperatures rise steadily from spring, peak in August, and gradually decline through autumn into winter.

These seasonal patterns make summer pleasant for travel, while winters can bring frost and occasional snowfall.

🌧️ Rainfall Distribution

Region-wide monthly rainfall · 1981–2025 · mm/month

🌧 Rainfall & Humidity in Hiroshima

Hiroshima receives its highest rainfall in July, while humidity peaks during summer months.
🌧️ Wettest: July — 225 mm☀️ Driest: January — 61 mm

💧 Humidity peaks at 85% in July · annual avg 81%

💨 Humidity & Wind Speed

Monthly averages · 1981–2025

🌍 Climate Summary

Avg Temp: 14.2°CAvg Rainfall: 1497 mmAvg Humidity: 81%Period: 1981–2025

Across 45 years, Hiroshima's temperature shows a slight warming trend over the past decade. 2024 was the warmest year overall and 1995 the coolest.

📅 Hiroshima Yearly Climate Trends

The warmest year on record was 2024 (avg: 15.6°C), while the coldest year was 1995 (avg: 13.3°C).

📊 Key Climate Trends

  • 🌡️ Hiroshima's temperature shows a slight warming trend over the past decade
  • 📈 Minimum temperatures show a slight warming trend in recent years
  • 🌧️ Rainfall has increased noticeably in recent years compared to earlier periods

🌡️ Annual Temperature Trend

View Range:

Averaged across all 20 cities in Hiroshima · Last 30 years · °C

Hiroshima's temperature shows a slight warming trend over the past decade. The region-wide average sits at 14.2°C with annual rainfall averaging 1497 mm.

🌧️ Annual Precipitation

View Range:

Averaged across all 20 cities in Hiroshima · Last 30 years · mm/year

Annual rainfall in Hiroshima shows noticeable variation. Rainfall has increased noticeably in recent years compared to earlier periods.
📅 Yearly Climate Data Overview

🔥 hottest  ·  ❄️ coldest  ·  🌧️ wettest

ℹ️ Values are averages across all 20 cities in Hiroshima for each year.

YearAvg HighAvg TempAvg LowHottest DayColdest DayRainfall (mm)Avg HumidityAvg Wind
2025
18.9°C14.9°C10.8°C34.8°C-7.2°C179682%2.2 m/s
2024 🔥 🌧️
19.5°C15.6°C11.6°C33.6°C-5.2°C205983%2.3 m/s
2023
19.5°C15.3°C11.1°C32.8°C-8.9°C182581%2.1 m/s
2022
19.2°C14.9°C10.5°C34.7°C-5.0°C120079%2.2 m/s
2021
18.8°C14.7°C10.5°C32.6°C-7.0°C199482%2.3 m/s
2020
18.8°C14.6°C10.4°C33.6°C-4.9°C180882%2.3 m/s
2019
19.1°C14.8°C10.5°C33.1°C-4.2°C135581%2.2 m/s
2018
18.5°C14.4°C10.2°C33.8°C-9.4°C186382%2.3 m/s
2017
18.1°C14.0°C9.9°C33.1°C-6.7°C161281%2.3 m/s
2016
18.8°C14.8°C10.7°C33.1°C-8.8°C194883%2.2 m/s

Showing 1 to 10 of 45 years

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❓ Frequently Asked Questions

What is the hottest city in Hiroshima?▼
Sera is the hottest city in Hiroshima with an average July high of 28.8°C based on 45 years of data. View Sera weather history →
What is the coldest city in Hiroshima?▼
Shōbara is the coldest city with average January lows of -2.4°C. View Shōbara weather history →
Which city in Hiroshima gets the most rain?▼
Etajima is the wettest city in Hiroshima with approximately 1534 mm of annual precipitation on average.
What is the warmest month in Hiroshima?▼
August is the warmest month in Hiroshima, with region-wide average highs of 29.9°C and average lows of 22.3°C.
What is the coldest month in Hiroshima?▼
January is the coldest month in Hiroshima with average lows of -0.3°C and average highs of 6.7°C.
What is the rainiest month in Hiroshima?▼
July is the rainiest month in Hiroshima with approximately 225 mm on average, while January is the driest with 61 mm.
How many cities in Hiroshima have weather data?▼
WeatherBlaze has historical weather data for 20 cities in Hiroshima, covering 45 years of climate records from 1981 to 2025.
Where does this climate data come from?▼
All data is sourced from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis data. It includes monthly temperature, precipitation, humidity, wind speed, and solar radiation.

📡 Data Source

All weather data is sourced from NASA POWER (Prediction of Worldwide Energy Resources), a NASA project providing solar and meteorological data for renewable energy, building efficiency, and agricultural research.

Parameters included:
  • Temperature (Min, Max)
  • Precipitation
  • Relative Humidity
  • Wind Speed
  • Solar Radiation
Data specifications:
  • Resolution: Monthly
  • Spatial: 0.5° × 0.625°
  • Source: MERRA-2
  • Coverage: 1981–2025
  • Cities: 20 in Hiroshima