May Weather in Iwakuni, Japan

Last updated: August 21, 2025

May in Iwakuni, Japan presents a delightful climate characterized by mild temperatures and notable humidity. The maximum temperature peaks at 28°C (83°F), while the average hovers around 19°C (66°F). As the month unfolds, the minimum temperature dips to 7°C (45°F), providing a refreshing contrast. However, the season also brings with it 136 mm (5.4 in) of precipitation over approximately 9 days, resulting in a humidity level of 84%, which adds a lush vibrancy to the surrounding landscape. This month offers an engaging blend of warmth and moisture, making it ideal for exploring the natural beauty of the region.

May Temperature in Iwakuni

In May, Iwakuni, Japan experiences a delightful transition into warmer weather as spring reaches its peak. With minimum temperatures rising to a comfortable 7°C (45°F) and average daily highs soaring to 28°C (83°F), this month marks the beginning of more pleasant days ahead. The average temperature climbs to a welcoming 19°C (66°F), creating an inviting atmosphere that encourages outdoor activities and exploration. Following a gradual increase from the chillier months of winter, May is a time when blossoms are vibrant, and the landscape comes alive, making it a perfect month for visitors to enjoy the beauty of Iwakuni.

May Weather in Iwakuni: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in Iwakuni, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Iwakuni, May typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec424350576672798275665545
Data source: Temperature data for Iwakuni generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

May Precipitation in Iwakuni

May in Iwakuni, Japan, sees a notable continuation of the wet season, with precipitation reaching 136 mm (5.4 in) over approximately 9 days of rain. This rainfall is slightly less than April's totals, yet it underscores a persistent trend of increasing precipitation leading into the summer months. As spring transitions, the region prepares for a wetter June, which typically brings more substantial rainfall. The consistent rainfall pattern in May not only supports lush greenery but also hints at the imminent shift towards the summer deluge that peaks in July, which can bring over double the precipitation experienced in May.

May Precipitation Trends in Iwakuni

The chart displays monthly precipitation patterns in Iwakuni, with values for each month alongside May’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May’s conditions compare to those of other months. In Iwakuni, May typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec49691251371361813862562371723762
Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.
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May Humidity in Iwakuni

May in Iwakuni, Japan, brings a notable rise in humidity, reaching a robust 84%. This increase marks a significant jump from the preceding months, particularly when compared to April's 75%. As spring gives way to early summer, Iwakuni's atmosphere becomes increasingly moist, providing a preview of the sweltering conditions that characterize the following months. June and July are particularly humid, with levels soaring to 88% and an astonishing 95%, respectively. This trend highlights a gradual progression towards the exceptionally sticky summer, making May a bridge between the mild spring and the heat to come.

May Average Humidity in Iwakuni

This chart illustrates the average monthly humidity levels in Iwakuni, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, average humidity in Iwakuni is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec76%72%69%75%84%88%95%93%84%79%76%75%
Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Iwakuni

As May unfolds in Iwakuni, Japan, residents and visitors alike should be prepared for extreme UV exposure, with the UV Index peaking at 11—matching the trend set in April. With a rapid increase from moderate levels in earlier months, such as January and February, to a concerning very high index in March, the sun’s intensity during this time necessitates caution, as the burn time drops to just 10 minutes. This aligns with a pattern that continues into June, highlighting the importance of sun protection as summer approaches. To stay informed and safe while enjoying outdoor activities, be sure to consult the Iwakuni UV Index.

Maximum UV Index Levels in Iwakuni for May

The chart shows the monthly maximum UV Index (UVI) for Iwakuni in May, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In May, the maximum UV index in Iwakuni typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec458111111121210764
Data source: Iwakuni May UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

May Sunshine in Iwakuni

As spring transitions into summer, May shines brightly in Iwakuni, Japan, boasting an impressive 303 hours of sunshine. This increase not only marks the peak of spring's vibrancy but also showcases a steady upward trend from the 266 hours in March to 282 hours in April. Following this sun-drenched month, the sunshine gradually tapers off into June, yet it remains a highlight of the season. Interestingly, this monthly total reflects Iwakuni's overall sunny disposition, with August ultimately taking the crown at 308 hours, further illustrating the warm, inviting climate that defines this picturesque locale throughout the year.

Monthly Sunshine Duration in Iwakuni: May Highlighted

The May sunshine duration represents the total number of hours Iwakuni experiences direct sunlight during the month of May, excluding cloudy or obstructed periods. This chart compares the sunshine duration of May with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec184h227h266h282h303h291h281h308h260h254h237h220h
Data source: Iwakuni May Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Iwakuni During May

In Iwakuni, Japan, the likelihood of sunny weather experiences a notable shift as spring gives way to summer. May stands out with a 31% chance of sunshine, a slight dip compared to the preceding months of April (47%) and March (40%). This declining trend continues into the summer months, where June sees only a 25% likelihood of sunny skies. While May might not boast the brightest forecast, it does remain relatively sunnier than the peak of summer. Looking ahead, the chance of sun increases again in the fall, making May a transitional month full of potential, even if it isn't the sunniest in the calendar year.

Percentage of Sunny Days in May in Iwakuni

The chart illustrates the percentage of sunny days in Iwakuni throughout the year, with May highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Iwakuni experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec43%50%40%47%31%25%23%25%31%59%52%55%
Data source: Iwakuni May chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Iwakuni in May

In Iwakuni, Japan, the transition from winter to summer unfolds beautifully through its daylight duration. Starting the year with a steady 10 hours in January and February, daylight begins to stretch gradually in March, reaching 11 hours. By April, the days become noticeably longer, with 13 hours of daylight, a trend that continues into May. Here, daylight remains consistent at 13 hours, providing a perfect backdrop for outdoor activities as spring blossoms. As June and July arrive, Iwakuni basks in the warmth of summer with a peak of 14 hours of daylight, offering ample time for exploration and adventure. The gradual decline begins in August, dipping to 13 hours, before transitioning into fall with shorter days in September (12 hours) and October (11 hours). The cycle of daylight in Iwakuni beautifully mirrors the changing seasons, inviting residents and visitors alike to savor each moment.

Average Daylight Hours in Iwakuni for May

The chart illustrates the variation in daylight duration in Iwakuni throughout the year, with May highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 8m10h 56m11h 58m13h 2m13h 55m14h 22m14h 9m13h 22m12h 21m11h 18m10h 22m9h 54m
Data source: Iwakuni daylight hours, calculated by summing the hours between sunrise and sunset for each day.

May Winds in Iwakuni

In Iwakuni, Japan, the month of May greets residents and visitors with a gentle breeze, showcasing an average wind speed of 2.8 m/s (6 mph). This calming wind is part of a broader trend observed from January to May, where the wind speeds remain relatively stable, hovering between 2.8 m/s and 3.3 m/s. Unlike the more robust gusts of earlier months, May's winds mirror the tranquility of spring, subtly preparing for the calm summer ahead. As temperatures rise and nature blooms, the consistent breeze invites outdoor exploration, offering a refreshing complement to the season’s warmth.

Average May Wind Speed in Iwakuni

The chart displays monthly wind speed patterns in Iwakuni, with values for each month shown alongside May's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how May's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec3.13.32.82.82.8 m/s1.82.02.62.32.32.83.3
Data source: Iwakuni May wind data, generated using information from the Copernicus Climate Change Service.

How May Weather in Iwakuni Compares to Other Months

Weather in Iwakuni varies notably across the year, with each month offering distinct climate conditions. This page compares May’s weather to other months in Iwakuni, focusing on differences in temperature, rainfall, humidity, and UV levels.

May and January present stark contrasts in weather. In May, temperatures range from a minimum of 7°C (45°F) to a pleasant average of 19°C (66°F), peaking at 28°C (83°F). This month sees a considerable amount of rainfall, accumulating 136 mm (5.4 in) over 9 days, accompanied by high humidity levels of 84%. In contrast, January experiences much colder temperatures, with a minimum of -4°C (25°F) and an average of just 5°C (42°F), reaching a maximum of 15°C (59°F). Precipitation during January is significantly lower at 49 mm (1.9 in) over 6 days, and the humidity is also lower at 76%. For more details, you can check Iwakuni weather in January.

May generally brings warmer temperatures compared to February, with average highs reaching 19°C (66°F) and maximums soaring to 28°C (83°F), in contrast to February's averages which peak at 20°C (68°F) but have a significantly lower average of 6°C (43°F). While May enjoys a more humid environment at 84%, February experiences a drier atmosphere with humidity at 72%. Additionally, May tends to be wetter with 136 mm (5.4 in) of precipitation over 9 days, compared to February's 69 mm (2.7 in) over just 7 days. For more details on February weather specifics, you can visit Iwakuni weather in February.

In comparing the weather conditions of May and March, it's evident that May is significantly warmer, with average temperatures reaching 19°C (66°F) compared to March's cooler average of 10°C (50°F). While both months experience a fair amount of precipitation, May has slightly higher rainfall at 136 mm (5.4 in) over 9 days, compared to March's 125 mm (4.9 in) over 10 days. Additionally, humidity levels are higher in May at 84%, indicating a more humid climate than March's 69%. This shift in weather highlights the transition from early spring to the onset of summer. For more detailed information on March weather specifics, you can check Iwakuni weather in March.

In comparing the weather of May and April, May tends to be noticeably warmer, with average temperatures rising from April's 14°C (58°F) to 19°C (66°F) and a higher maximum temperature of 28°C (83°F) compared to April's high of 24°C (76°F). Both months experience similar levels of precipitation—approximately 136 mm (5.4 in) over 9 days—but May features a higher humidity rate of 84%, contrasting with April's 75%. For more details on April weather, you can check Iwakuni weather in April.

Comparing the weather in May and June reveals noticeable differences in temperature and precipitation. May typically experiences milder temperatures, with a minimum of 7°C (45°F), an average of 19°C (66°F), and a maximum of 28°C (83°F). In contrast, June sees a rise in warmth, with minimum temperatures starting at 14°C (57°F) and an average of 22°C (72°F), peaking at 29°C (85°F). However, June is also characterized by increased precipitation, averaging 181 mm (7.1 in) over 14 days, compared to May's 136 mm (5.4 in) over just 9 days. The humidity also rises slightly from 84% in May to 88% in June, contributing to a more tropical feel as summer approaches. For more detailed information, check out Iwakuni weather in June.

May and July present distinctly different weather patterns. In May, temperatures range from a cool minimum of 7°C (45°F) to a comfortable average of 19°C (66°F), peaking at 28°C (83°F). However, May is relatively rainy, with 136 mm (5.4 in) of precipitation spread over 9 days, accompanied by a humidity level of 84%. In contrast, July experiences much warmer temperatures, with a minimum of 18°C (65°F) and an average of 26°C (79°F), reaching a high of 35°C (95°F). July also sees significantly more rainfall, totaling 386 mm (15.2 in) over 19 days, and the humidity rises to 95%. For more specific details about the weather conditions in July, check out Iwakuni weather in July.

May and August showcase significant variations in weather patterns. In May, temperatures range from a comfortable minimum of 7°C (45°F) to an average of 19°C (66°F), peaking at a maximum of 28°C (83°F). The month sees regular rainfall, with 136 mm (5.4 in) of precipitation over about 9 days, accompanied by a humidity level of 84%. In contrast, August experiences much warmer temperatures, with a minimum of 20°C (67°F) and an average of 28°C (82°F) that can soar up to 35°C (96°F). Rainfall is also more prevalent, totaling 256 mm (10.1 in) over approximately 14 days, and humidity increases to 93%. For a more detailed look at August weather, you can refer to this link: Iwakuni weather in August.

May and September offer distinctly different weather experiences. In May, temperatures range from a chilly 7°C (45°F) at night to a warm 28°C (83°F) during the day, with an average of 19°C (66°F). The month sees around 136 mm (5.4 in) of precipitation over roughly 9 days, contributing to its high humidity of 84%. In contrast, September brings warmer nights with minimum temperatures of 15°C (60°F) and daytime highs reaching up to 33°C (92°F), averaging 24°C (75°F). However, it is also wetter, with about 237 mm (9.3 in) of rainfall spread across 14 days, while maintaining the same humidity of 84%. For more specific details, you can check Iwakuni weather in September.

In May, temperatures range from a minimum of 7°C (45°F) to a maximum of 28°C (83°F), with an average of 19°C (66°F). The month experiences about 136 mm (5.4 in) of precipitation over 9 days, accompanied by a high humidity level of 84%. In contrast, October sees slightly warmer temperatures, with a minimum of 8°C (46°F) and a maximum reaching 29°C (85°F), while maintaining the same average of 19°C (66°F). However, it brings more rainfall, totaling 172 mm (6.8 in) over 10 days, and a lower humidity level of 79%. For more detailed insights, check out Iwakuni weather in October.

May and November present distinct weather characteristics that highlight the transition between spring and autumn. In May, temperatures range from a minimum of 7°C (45°F) to a maximum of 28°C (83°F), with an average of 19°C (66°F). The month experiences significant rainfall, totaling 136 mm (5.4 in) over approximately 9 days, coupled with high humidity at 84%. In contrast, November features cooler temperatures, with a minimum of 2°C (36°F), an average of 13°C (55°F), and a maximum of 23°C (74°F). Precipitation is considerably lower at 37 mm (1.5 in) over about 5 days, and humidity is also reduced to 76%. This comparison underscores the warmer, wetter conditions of May against the cooler, drier climate typical of November. For more details, check Iwakuni weather in November.

May and December present a stark contrast in weather conditions. In May, temperatures range from a mild 7°C (45°F) to a warm 28°C (83°F), with an average of 19°C (66°F), while December sees much cooler temperatures, with a minimum of -1°C (31°F) and a maximum of 20°C (69°F), averaging only 7°C (46°F). Additionally, May experiences significantly more precipitation at 136 mm (5.4 in) over nine days, compared to December's 61 mm (2.4 in) over just six days. Although May has a higher humidity level of 84%, December's humidity remains relatively comfortable at 75%. For a detailed look at December's weather, check out Iwakuni weather in December.

Compare Iwakuni's Climate with Cities Worldwide

Conclusion: What to Expect From May Weather in Iwakuni

As May unfolds in Iwakuni, the weather begins to transition into a more temperate and inviting phase compared to the chillier months before it. Average temperatures rise, bringing a refreshing warmth that makes outdoor activities more enjoyable. With maximums reaching up to 28°C (83°F) and minimums around 7°C (45°F), the month offers a comfortable range for varied preferences. However, it also marks the beginning of the rainy season, with 9 days of precipitation and humidity lingering at a high 84%. This blend of warmth and moisture contrasts with the drier conditions of earlier months, creating a lush environment that hints at the vibrant summer ahead. For a deeper understanding of Iwakuni's evolving weather patterns, visit Iwakuni Climate.