Climate and monthly weather forecastHiroshima, Japan
Climate and monthly weather forecast
The climate of Hiroshima
Hiroshima, located in the western part of the Hokkaido region in Japan, is classified under the Köppen climate system as Cfa. This demonstrates that it experiences a humid subtropical climate with no dry season. Throughout the year, the weather in Hiroshima is quite dynamic with noticeable variations in different weather components.By examining the collected data, it becomes clear that the city experiences marked increases and decreases in temperature, humidity, and rainfall over the course of the year. To give a specific illustration, average high temperatures range from 9.7°C (49.5°F) in the coldest months to 32.5°C (90.5°F) in the hottest months. The city also endures a significant amount of rainfall each month, reaching its peak at 259mm (10.2") in the month of July and its low at 41mm (1.61") in December. The trend in relative humidity fluctuates as well, with January and December at the higher end with 69%, while April sees a low of 63%.
In terms of unique weather patterns, Hiroshima exhibits remarkable features. July is not only the hottest month, with an average high temperature of 32.5°C (90.5°F), but it also is the month with the highest rainfall, at 259mm (10.2"). The city sees minimal snowfall, primarily between December and February, while the rest of the year typically sees no snow at all.
The best time to visit Hiroshima
Given its climatic variations, the most appropriate time to visit Hiroshima would be from late March to early May or from September to November. During these periods, the city experiences mild climates, with average high temperatures from 19.7°C (67.5°F) to 24.1°C (75.4°F) in spring and from 23.4°C (74.1°F) to 29°C (84.2°F) in autumn. Furthermore, these periods feature lower than average rainfall, ensuring comfortable conditions for sightseeing and outdoor activities.The worst time to visit Hiroshima
The less ideal time to visit Hiroshima would be from June to August. These months experience not only the highest average high temperatures, ranging from 27.2°C (81°F) to 32.5°C (90.5°F), but also the heaviest rainfall, reaching highs of 247mm (9.72") in June to 259mm (10.2") in July. Additionally, July is typically the most humid month making it less comfortable for outdoor exploration.Spring weather in Hiroshima
Spring in Hiroshima, which lasts from March to May, is generally warm and pleasant. Temperatures range from 14°C (57.2°F) to 24.1°C (75.4°F), with minimal snowfall. The amount of rainfall is relatively low compared to other seasons, making it comfortable for outdoor activities. The relative humidity level hovers between 63% to 66%, creating a generally comfortable climate.Summer weather in Hiroshima
Summer, extending from June to August, is the hottest and wettest season in Hiroshima. During this period, temperatures can soar up to 32.5°C (90.5°F). The city sees the highest accumulation of rainfall during these months, reaching a peak of 259mm (10.2") in July. Furthermore, the humidity level significantly spikes, causing discomfort to those unaccustomed to such conditions.Autumn weather in Hiroshima
Autumn, from September to November, brings a respite from the intense heat and rainfall of summer. During these months, Hiroshima experiences dropping temperatures, from 29°C (84.2°F) to 17.4°C (63.3°F), and a decrease in rainfall, from 170mm (6.69") to 68mm (2.68"). The relative humidity during this season lies from 68% to 70%, making it rather comfortable for visitors.Winter weather in Hiroshima
The winter months, from December to February, are the coldest with temperatures going down to a low of 1.7°C (35.1°F) in January. This season sees Hiroshima experiencing minimal snowfall, peaking at 50mm (1.97") in December. Rainfall is also substantially lower compared to other seasons, lowering to 41mm (1.61") in December. Due to this cold weather, outdoor activities might be slightly difficult during this time.Weather in January
In Hiroshima, January sees frozen soil as snowfall reaches up to 50mm (1.97") over around 9 days. When compared to February, temperatures ride the low end of the thermometer, amplifying icy conditions. It is particularly chilly in the mornings with frosts a common sight. Weather in January »Weather in February
February in Hiroshima is still chilly, though the mercury creeps up a bit from January. The snowfall lessens with depth reducing to 40mm (1.57"), making it lighter than the previous month. Though it’s warmer, the weather remains wet, creating a moist cold that could settle itself into one's bones. Weather in February »Weather in March
Heading into March, Hiroshima undergoes a significant transition with snowfall decreasing to 10mm (0.39"). March's weather signals the beginning of the transition to spring, moving away from the harsh winter of the previous months. Weather in March »Weather in April
In April, the weather in Hiroshima enters firmly into spring mode, with a more pleasant climate and no snowfall occurrence. The rising temperatures create a vibrant atmosphere, adding to the vibrance of the city’s iconic cherry blossom season. Weather in April »Weather in May
May's weather in Hiroshima sees a noticeable shift towards the warmer side with temperatures beginning to feel like early summer. Rainfall surges to 178mm (7.01"), hinting that the monsoon months are nearing. While the temperatures rise, so does the humidity, making the air feel slightly heavy. Weather in May »Weather in June
June signals the beginning of the monsoon season in Hiroshima with the rainfall reaching a high of 247mm (9.72"). The intensity and frequency of rainfall increase from May, signaling a shift in weather patterns. Despite the heightening rainfall, temperatures continue to rise, creating a humid and warm environment. Weather in June »Weather in July
July in Hiroshima brings the year's highest temperature, soaring to 30.8°C (87.4°F), offering a hot, summer environment during the peak travel season. As the rainfall continues at a high pace, the high humidity intensifies the perceived heat. Weather in July »Weather in August
Wide fluctuations in Hiroshima's weather patterns become evident in August when the rainfall significantly lowers down to 111mm (4.37") from 259mm (10.2") in July. Despite the reduction in rainfall, temperatures remain high with the warmest sea temperatures of the year crowning August as a preferred time for beachgoers. Weather in August »Weather in September
September brings a pleasant change to Hiroshima's weather with temperatures beginning to tone down from the summer highs. While the rainfall shows an uptick from August, it does not match the intense monsoon-like conditions of June or July. Weather in September »Weather in October
October's weather in Hiroshima is notably cooler than September with temperatures reflecting strong autumnal vibes. A significant drop in rainfall, down to 88mm (3.46"), makes October a drier month compared to the preceding monsoon months. Weather in October »Weather in November
With temperatures further dropping to a low of 8.5°C (47.3°F), November weather in Hiroshima welcomes late autumn. The rainfall slacks off even more, making it quite a dry month considering Hiroshima's typically wet climate. Weather in November »Weather in December
December in Hiroshima indicates the return of winter with temperatures dropping, snowfall reappearing at 30mm (1.18"), and daylight dwindling. The rainfall lessens, reaching the lowest point of the year, echoing typical winter patterns. Weather in December »Updated: Jan 31, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
With average high and low temperatures of 9.7°C (49.5°F) and 1.7°C (35.1°F) respectively, January is Hiroshima's coldest month.
Throughout the year, in Hiroshima, there are 190 rainfall days, and 1538mm (60.55") of precipitation is accumulated.
January through March and December are months with snowfall.
The month with the most snowfall is January, when snow falls for 8.7 days and typically aggregates up to 50mm (1.97") of snow.
In Hiroshima, Japan, during the entire year, snow falls for 23.1 days and aggregates up to 130mm (5.12") of snow.
The month with the least sunshine is January, with an average of 4.4h of sunshine.
The months with the lowest UV index in Hiroshima, Japan, are January and December, with an average maximum UV index of 3.
The month with the coldest seawater in Hiroshima is February, with an average sea temperature of 12.4°C (54.3°F).
The least humid month in Hiroshima is April, with an average relative humidity of 63%.
In Hiroshima, Japan, snow does not fall in April through November.
With an average of 14h and 24min of daylight, June has the longest days of the year in Hiroshima.
July is the most humid month in Hiroshima, with an average relative humidity of 74%.
July is the month with the most rainfall. Rain falls for 17 days and accumulates 259mm (10.2") of precipitation.
The month with the highest UV index in Hiroshima is July, with an average maximum UV index of 11.
The warmest period in Hiroshima tends to be August, when average temperatures fluctuate between a high of 32.5°C (90.5°F) and a low of 24.8°C (76.6°F).
With an average sea temperature of 26.8°C (80.2°F), August is the month with the warmest seawater.
The month with the most sunshine in Hiroshima is August, with an average of 6.8h of sunshine.
The month with the least rainfall is December, when the rain falls for 17 days and typically collects 41mm (1.61") of precipitation.
With an average of 9h and 54min of daylight, December has the shortest days of the year in Hiroshima, Japan.
Hiroshima does not utilize Daylight Saving Time (DST). JST timezone is used throughout the entire year.
Average temperature
Hiroshima, Japan
The warmest month (with the highest average high temperature) is August (32.5°C).
The month with the lowest average high temperature is January (9.7°C).
The month with the highest average low temperature is August (24.8°C).
The coldest month (with the lowest average low temperature) is January (1.7°C).
Average humidity
Hiroshima, Japan
The month with the highest relative humidity is July (74%).
The month with the lowest relative humidity is April (63%).
Average rainfall
Hiroshima, Japan
- Average rainfall in January:
44.6mm - Average rainfall in February:
66.6mm - Average rainfall in March:
123.9mm - Average rainfall in April:
141.7mm - Average rainfall in May:
177.6mm - Average rainfall in June:
247mm
- Average rainfall in July:
258.6mm - Average rainfall in August:
110.8mm - Average rainfall in September:
169.5mm - Average rainfall in October:
87.9mm - Average rainfall in November:
68.2mm - Average rainfall in December:
41.2mm
The wettest month (with the highest rainfall) is July (258.6mm).
The driest month (with the least rainfall) is December (41.2mm).
Average rainfall days
Hiroshima, Japan
- Average rainfall days in January:
19 days - Average rainfall days in February:
18 days - Average rainfall days in March:
18 days - Average rainfall days in April:
15 days - Average rainfall days in May:
14 days - Average rainfall days in June:
17 days
- Average rainfall days in July:
17 days - Average rainfall days in August:
14 days - Average rainfall days in September:
16 days - Average rainfall days in October:
12 days - Average rainfall days in November:
13 days - Average rainfall days in December:
17 days
The month with the highest number of rainy days is January (19 days).
The month with the least rainy days is October (12 days).
Average snowfall
Hiroshima, Japan
The month with the highest snowfall is January (50mm).
The months with the least snowfall are April, May, June, July, August, September, October and November (0mm).
Average snowfall days
Hiroshima, Japan
- Average snowfall days in January:
8.7 days - Average snowfall days in February:
7.1 days - Average snowfall days in March:
2.6 days - Average snowfall days in April:
0 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0 days - Average snowfall days in November:
0.2 days - Average snowfall days in December:
4.5 days
The month with the highest number of snowfall days is January (8.7 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average sea temperature
Hiroshima, Japan
The best month for swimming (with the highest average sea temperature) is August (26.8°C).
The coldest month (with the lowest average sea temperature) is February (12.4°C).
Average daylight / Average sunshine
Hiroshima, Japan
- Average daylight in January:
10h and 12min - Average daylight in February:
11h and 0min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 6min - Average daylight in May:
14h and 0min - Average daylight in June:
14h and 24min
- Average daylight in July:
14h and 12min - Average daylight in August:
13h and 24min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 18min - Average daylight in November:
10h and 24min - Average daylight in December:
9h and 54min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in January:
4h and 24min - Average sunshine in February:
5h and 0min - Average sunshine in March:
5h and 30min - Average sunshine in April:
6h and 18min - Average sunshine in May:
6h and 42min - Average sunshine in June:
5h and 24min
- Average sunshine in July:
5h and 48min - Average sunshine in August:
6h and 48min - Average sunshine in September:
5h and 30min - Average sunshine in October:
5h and 54min - Average sunshine in November:
5h and 6min - Average sunshine in December:
4h and 48min
The month with the most sunshine is August (Average sunshine: 6h and 48min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average UV index
Hiroshima, Japan
The month with the highest UV index is July (UV index 11).
The months with the lowest UV index are January and December (UV index 3).
