Last updated: August 21, 2025
September in Onomichi, Japan, offers a dynamic climate that reflects the transition from summer to autumn. The maximum temperature can soar to an impressive 35°C (95°F), while the average is a more moderate 25°C (77°F), providing a warm backdrop for outdoor activities. However, as the month progresses, cooler days emerge, with minimum temperatures dipping to 14°C (58°F). Residents and visitors alike should prepare for frequent rain, with 174 mm (6.9 in) of precipitation over approximately 12 days, contributing to a humid atmosphere that hovers around 87% humidity. This blend of warmth and moisture makes September a month of vibrant landscapes and lush scenery, ideal for exploring the cultural richness of Onomichi.
In September, Onomichi experiences a comfortable transition from the heat of summer to the cooler embraces of autumn. With minimum temperatures around 14°C (58°F) and average highs reaching a pleasant 25°C (77°F), the weather is perfect for outdoor exploration and enjoying the vibrant autumn foliage. As the month progresses, temperatures can soar to a maximum of 35°C (95°F), reminiscent of the lingering warmth from July and August, yet a notable shift towards cooler evenings is palpable. This gradual decrease, in contrast to the sweltering summer months, makes September an ideal time for travelers seeking to savor the beauty of this picturesque coastal town without the intense heat, while still enjoying mild and welcoming days.
In September, Onomichi experiences a notable shift in its weather pattern, with precipitation reaching 174 mm (6.9 in) over 12 days. This marks an increase from the previous month, where rainfall totaled 166 mm, highlighting a seasonal uptick in moisture as summer transitions into autumn. The city's July peak of 314 mm (12.4 in) sets a high standard for precipitation in the warmer months, but September's figures suggest a steady rhythm of rain that prepares the region for the drier autumn ahead. Comparatively, this month stays wetter than the later months, like October, which sees a decrease to 164 mm, indicating that September serves as a critical bridge in Onomichi's annual climatic narrative.
In September, Onomichi, Japan experiences a notable drop in humidity to 87%, continuing the trend of elevated moisture typical of the summer months. The city's humidity peaks during the sweltering July and August, reaching an impressive 92%, but as autumn approaches, conditions become slightly more comfortable. Comparatively, September's humidity remains higher than in the spring months, where percentages range between 73% and 74%. This gradual transition hints at the looming arrival of crisp autumn air, yet retains enough warmth to remind residents of summer's linger. Overall, the humidity in September reflects a balancing act, ushering in seasonal change while still holding onto the rich moisture that characterizes the region.
As September unfolds in Onomichi, Japan, the UV Index settles at a very high rating of 10, indicating that sun protection is essential for outdoor activities. This marks a shift from the intense extremes of summer, where the UV Index peaked at 12 in both July and August, necessitating a swift 10-minute burn time. As the summer sun gradually softens, September still demands vigilance, reducing burn time to 15 minutes. Interestingly, the trend in UV exposure throughout the year showcases a gradual rise from January’s UV Index of 4 to May's extreme levels, before tapering off into the more moderate autumn months. Given this variability, staying informed is key to enjoying the outdoors safely. For more details on UV Index levels throughout the year, visit Onomichi UV Index.
UV Risk Categories
September in Onomichi, Japan, shines with 261 hours of sunlight, marking a gentle decline from August's vibrant 309 hours. As summer transitions into autumn, the city enjoys a still plentiful supply of sunshine, contributing to the warmth and charm of the season. This monthly sun exposure reflects a broader trend, where the summer months boast the highest solar hours—peaking in August—before gradually tapering off into the cooler fall and winter months. The sun-soaked days of September serve as a beautiful farewell to summer, inviting residents and visitors alike to savor the lingering warmth before the year draws to a close. With October bringing 251 hours of sunlight, the inviting glow of September reminds us of the ephemeral nature of summer's embrace in this picturesque coastal town.
In Onomichi, Japan, the likelihood of sunny weather sees a gradual decline during the summer months, hitting a low of just 24% in July and 28% in August. However, as September arrives, the chance of sunlight slightly rebounds to 32%, indicating a subtle shift towards more favorable weather as autumn approaches. This upward trend continues into October, where the possibility of sunshine enhances significantly to 57%, suggesting that while summer may bring humid days, early autumn in Onomichi offers a promising return to sunnier skies. With November and December also maintaining 55% and 61% respectively, it's clear that the latter part of the year is more hospitable for sun-lovers in this picturesque region.
As summer transitions into autumn, September in Onomichi, Japan offers a delightful balance with about 12 hours of daylight. This month marks a gentle decline from the sunniest months of July and June, each basking in 14 hours of bright light. With the gradual shift, residents and visitors alike can enjoy the lingering warmth of late summer while embracing the cooler days ahead. Following September, daylight hours continue to decrease, dipping to 11 hours in October, before settling into the shorter days of winter. This rhythm of daylight provides a perfect backdrop for experiencing the vibrant hues of early autumn in Onomichi.
As September rolls into Onomichi, Japan, the gentle embrace of the wind continues its summer trend with an average speed of 2.4 m/s (5 mph), mirroring the breezy consistency of the preceding months. Following a slight dip in June and July, when winds whispered softly through the city's scenic landscapes, September's calmness maintains this serene momentum. The subtle shift in wind patterns, from the robust gusts of winter to summer's gentle breezes, highlights a delicate balance in nature, inviting both locals and visitors to savor the tranquil beauty of autumn as it gently unfolds. With October closely following, the winds remain steadfastly mild, creating a perfect backdrop for the vibrant fall foliage to flourish.
Weather in Onomichi varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Onomichi, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present stark contrasts in weather. September boasts warmer temperatures, with a minimum of 14°C (58°F) and an average of 25°C (77°F), peaking at a sweltering 35°C (95°F). The month also experiences considerable precipitation, totaling 174 mm (6.9 in) over 12 days, coupled with high humidity levels at 87%. In contrast, January brings a chill, with temperatures dipping as low as -5°C (24°F) and averaging only 6°C (43°F), reaching a maximum of 15°C (59°F). The winter month sees significantly less rainfall, around 40 mm (1.6 in) over just 5 days, while humidity remains relatively lower at 82%. For more detailed insights, check out Onomichi weather in January.
September and February present stark contrasts in weather conditions. September boasts warmer temperatures, with a minimum of 14°C (58°F) and an average high reaching up to 35°C (95°F), while February experiences much colder temperatures, ranging from a minimum of -3°C (26°F) to a maximum of 20°C (69°F). Additionally, September is characterized by higher humidity at 87% and significant precipitation of 174 mm (6.9 in) over approximately 12 days, compared to February's more moderate 54 mm (2.1 in) of rainfall over just 6 days. These differences create distinctly varied atmospheres between the late summer and early winter months. For more specific details about February weather, check Onomichi weather in February.
September and March present starkly contrasting weather conditions. In September, temperatures range from a minimum of 14°C (58°F) to a scorching maximum of 35°C (95°F), with an average of 25°C (77°F). This month experiences heavy rainfall, totaling 174 mm (6.9 in) across 12 days and high humidity at 87%. In contrast, March offers a much cooler climate, with temperatures ranging from 0°C (32°F) to a maximum of 23°C (73°F) and an average of 10°C (51°F). Rainfall is significantly less, at 93 mm (3.7 in) over 9 days, with humidity at a lower 73%. For more detailed information about March weather, you can visit Onomichi weather in March.
September and April present notably different weather patterns. In September, temperatures range from a minimum of 14°C (58°F) to a high of 35°C (95°F), averaging around 25°C (77°F). This month also experiences higher humidity at 87% along with substantial rainfall of 174 mm (6.9 in) over approximately 12 days. In contrast, April features much cooler weather, with temperatures dipping to a minimum of 2°C (36°F) and peaking at 26°C (79°F), averaging 15°C (59°F). The month sees less precipitation at 117 mm (4.6 in) over about 8 days and a lower humidity of 74%. For more detailed information, you can refer to Onomichi weather in April.
When comparing the weather between September and May, there are notable differences in temperature, precipitation, and humidity. September tends to be warmer, with average temperatures reaching 25°C (77°F) and highs soaring up to 35°C (95°F). In contrast, May is milder, with an average temperature of 20°C (68°F) and maximum temperatures that cap at 31°C (89°F). Rainfall is more abundant in September, averaging 174 mm (6.9 in) over 12 days, compared to May's 107 mm (4.2 in) over just 9 days. Additionally, while both months experience high humidity, September is slightly more humid at 87% compared to May's 84%. These climatic variations can significantly influence outdoor activities and travel plans. For more insights on specific conditions, you can refer to Onomichi weather in May.
When comparing the weather in September and June, notable differences in temperature and precipitation patterns emerge. September tends to be slightly warmer, with average temperatures reaching 25°C (77°F) and maxima soaring to 35°C (95°F), while June has a cooler average of 23°C (74°F) and a maximum of 32°C (90°F). Both months experience a similar number of rainy days, with precipitation levels at 174 mm (6.9 in) in September compared to 149 mm (5.9 in) in June. Humidity remains fairly consistent between the two months, at 87% in September and 86% in June. For more details on June weather, you can check Onomichi weather in June.
In comparing the weather between September and July, September generally sees milder temperatures, with minimums around 14°C (58°F) and maximums reaching 35°C (95°F), while July tends to be warmer, featuring minimums of 19°C (66°F) and maximums peaking at 38°C (100°F). July experiences significantly higher precipitation, totaling 314 mm (12.4 in) over 17 days compared to September's 174 mm (6.9 in) spread across 12 days. Humidity levels are slightly higher in July at 92%, versus September's 87%. For more detailed information on July weather, you can check out Onomichi weather in July.
In comparing the weather between September and August, September tends to be cooler, with minimum temperatures dropping to 14°C (58°F) compared to August's warmer minimum of 20°C (68°F). The average temperature in September is 25°C (77°F), while in August, it remains higher at 29°C (85°F). Maximum temperatures in September peak at 35°C (95°F), slightly cooler than August's high of 37°C (99°F). Additionally, September experiences a bit more precipitation, with 174 mm (6.9 in) over 12 days, compared to August’s 166 mm (6.5 in) across 11 days. Humidity levels are also slightly lower in September at 87%, while August sees a higher humidity of 92%. For more detailed information, you can visit Onomichi weather in August.
In September, the weather is characterized by warmer temperatures, with averages around 25°C (77°F) and maximums reaching up to 35°C (95°F). This month experiences significant rainfall, totaling 174 mm (6.9 in) over approximately 12 days, and humidity levels are high at 87%. In contrast, October sees a notable drop in temperature, with averages cooling to 19°C (67°F) and maximums of 32°C (89°F). The precipitation slightly decreases to 164 mm (6.4 in) over 9 days, accompanied by a marginally lower humidity level of 85%. For more details on October weather patterns, you can check Onomichi weather in October.
September and November present distinct contrasts in weather characteristics. September typically enjoys a warmer climate, with average temperatures reaching a comfortable 25°C (77°F) and maximums soaring to 35°C (95°F). However, it also comes with considerable humidity at 87%, alongside significant precipitation of 174 mm (6.9 in) over 12 days. In contrast, November brings a much cooler ambiance, with average temperatures dropping to 13°C (56°F) and nighttime lows dipping to around 1°C (35°F). This month sees a much drier landscape, with only 31 mm (1.2 in) of precipitation occurring over just 4 days, and humidity levels slightly lower at 84%. For those interested in specific conditions during this time, further details can be found in this link: Onomichi weather in November.
September and December present distinctly different weather patterns. In September, temperatures can range from a mild 14°C (58°F) to a scorching 35°C (95°F), with an average of 25°C (77°F). This month is also quite humid, with an average humidity of 87% and significant precipitation of 174 mm (6.9 in) over about 12 days. In contrast, December experiences much cooler temperatures, ranging from a minimum of 0°C (32°F) to a maximum of 20°C (69°F), with an average temperature of just 8°C (46°F). The month sees considerably less precipitation, totaling only 45 mm (1.8 in) across about 6 days, and slightly lower humidity at 82%. For more detailed insights on the weather during this chilly month, check out Onomichi weather in December.
As September arrives in Onomichi, the weather showcases a distinct transition compared to the sweltering summer months. While daytime temperatures can still reach a high of 35°C (95°F), the average settles comfortably at 25°C (77°F), marking a welcoming change. This month experiences a noticeable increase in humidity, hovering around 87%, contributing to a humid yet pleasant feel. With 174 mm (6.9 in) of precipitation over about 12 days, showers become more frequent, providing much-needed relief and refreshing the landscape. Overall, September invites residents and visitors alike to enjoy the lingering warmth while also embracing the gentle shift towards autumn. For more detailed insights, check out the Onomichi Climate.