September Weather in Shirahama, Japan

Last updated: August 21, 2025

September in Shirahama, Japan offers a warm climate, with maximum temperatures reaching 30°C (86°F) and an average of 25°C (77°F). Visitors can expect mild evenings, as minimum temperatures hover around 19°C (67°F). However, this month also brings considerable precipitation, totaling 239 mm (9.4 in) over 16 rainy days, contributing to a notably high humidity level of 82%. Amidst the occasional showers, the lush landscapes of Shirahama thrive, making it a picturesque yet variable time to explore this coastal gem.

September Temperature in Shirahama

In September, Shirahama experiences a pleasant transition as summer gradually gives way to autumn. With minimum temperatures resting at a mild 19°C (67°F) and averaging around 25°C (77°F), the warmth remains inviting for beachgoers and nature enthusiasts alike. The maximum temperature peaks at about 30°C (86°F), making it one of the last opportunities for sun-filled days. This month marks a notable shift from the sweltering heat of August, as the cooler evenings hint at the approaching fall. Overall, September in Shirahama offers a perfect blend of warmth while gradually embracing the refreshing embrace of autumn.

September Weather in Shirahama: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Shirahama, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Shirahama, September 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).
JanFebMarAprMayJunJulAugSepOctNovDec474753596672788177696052
Data source: Temperature data for Shirahama 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.

September Precipitation in Shirahama

September in Shirahama, Japan, marks a notable transition in the region’s climatic patterns, as the monthly precipitation rises to 239 mm (9.4 in), closely following August's heavier rainfall of 227 mm. This uptick coincides with an increase in rainy days, totaling 16, making it one of the wetter months of the year. The trend suggests that as summer wanes, the region experiences a blend of lingering warmth and moisture, paving the way for the more substantial rainfall seen in October. The consistent rise in precipitation from June through September reflects the area's humid subtropical climate, enchanting visitors with its lush landscapes revitalized by the abundant rain.

September Precipitation Trends in Shirahama

The chart displays monthly precipitation patterns in Shirahama, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Shirahama, September typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec77981491482042383532272393077285
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Shirahama

In September, Shirahama, Japan experiences a notable shift in humidity, with levels averaging 82%. This figure reflects a slight decrease from the peak summer months of July and August, which boast humidity levels of 92% and 86%, respectively. As the transition into autumn begins, September's humidity remains relatively high compared to the early months of the year, when humidity hovers around the low 70s percent. The persistent humidity throughout the summer months signals a lush environment, making Shirahama an attractive destination for those seeking warmth and vibrant landscapes. However, as the cooler October approaches, humidity levels will gradually edge down, hinting at the seasonal changes to come.

September Average Humidity in Shirahama

This chart illustrates the average monthly humidity levels in Shirahama, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Shirahama is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec72%69%69%75%82%87%92%86%82%79%76%74%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Shirahama

As September arrives in Shirahama, Japan, residents and visitors alike experience a notable shift in sunlight intensity, with a UV Index of 10, marking it as a period of very high exposure. Compared to the peak summer months, the UV levels drop slightly from July's maximum of 12, yet caution is still warranted as the burn time shortens to 15 minutes. This transition into autumn encourages sun safety awareness while still allowing outdoor enjoyment before seasonal changes take hold. With the UV Index consistently trending high throughout the summer, September serves as a reminder to protect your skin with sunscreen and protective clothing. For more information on UV levels throughout the year, visit the Shirahama UV Index.

Maximum UV Index Levels in Shirahama for September

The chart shows the monthly maximum UV Index (UVI) for Shirahama in September, 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 September, the maximum UV index in Shirahama typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec469101111121110764
Data source: Shirahama September 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.

September Sunshine in Shirahama

In Shirahama, Japan, September sees a delightful 265 hours of sunshine, making it a perfectly lit month for beachgoers and outdoor enthusiasts. As summer wanes, the sun's warm embrace gradually softens compared to August's peak of 323 hours. However, with September's sunshine hours remaining robust, it bridges the transition to autumn while offering a gentle farewell to summer's brightness. This downward trend from summer to autumn is mirrored in the months that follow, where October and November present increasingly shorter days. For those seeking to bask in the mellow glow of early fall, September in Shirahama remains a splendid choice, blending vibrant days with the promise of cooler weather ahead.

Monthly Sunshine Duration in Shirahama: September Highlighted

The September sunshine duration represents the total number of hours Shirahama experiences direct sunlight during the month of September, excluding cloudy or obstructed periods. This chart compares the sunshine duration of September with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec188h232h273h284h297h276h286h323h265h244h243h231h
Data source: Shirahama September Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Shirahama During September

In Shirahama, Japan, September offers a lesser chance of sunshine, with only 29% likelihood of clear skies. This marks a continuation of the trend seen in the summer months, where July and August also reflect low sunny possibilities at 30% and 31%, respectively. As summer fades, residents and visitors may find themselves hoping for a few bright days before the weather shifts dramatically in October, when the chance of sunshine surges to 63%. Overall, September sits at the tail end of a season characterized by unreliable weather, making it a month not particularly known for basking in the sun.

Percentage of Sunny Days in September in Shirahama

The chart illustrates the percentage of sunny days in Shirahama throughout the year, with September 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 Shirahama experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec45%54%46%49%29%25%30%32%29%63%55%59%
Data source: Shirahama September chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Shirahama in September

As summer wanes, September in Shirahama, Japan, offers a gentle transition in daylight, with approximately 12 hours of sunlight each day. This marks a slight decrease from the 14 hours seen in the peak of July and June, as the region gradually shifts toward autumn. Following the sunny months, daylight dips further in October to 11 hours, signaling the approach of shorter days. Throughout the year, a clear trend emerges: from the long, sun-soaked days of early summer to the cozy, diminishing daylight of fall and winter, Shirahama's daylight patterns beautifully reflect the changing seasons.

Average Daylight Hours in Shirahama for September

The chart illustrates the variation in daylight duration in Shirahama throughout the year, with September highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec10h 10m10h 57m11h 58m13h 1m13h 54m14h 20m14h 7m13h 21m12h 21m11h 18m10h 24m9h 56m
Data source: Shirahama daylight hours, calculated by summing the hours between sunrise and sunset for each day.

September Winds in Shirahama

As September rolls in Shirahama, Japan, the coastal breezes begin to shift, settling at a moderate average wind speed of 4.4 m/s (10 mph). This period marks a gentle transition from the summer's warmer, more vigorous winds, which peaked in August at 5.1 m/s (11 mph). The trend reveals a gradual decrease in wind speed as the year progresses towards the crispness of autumn; however, September still retains a welcoming lightness in the air. In October, a slight uptick to 4.9 m/s (11 mph) hints at the seasonal shifts that lie ahead, preparing the landscape for the invigorating winds of fall. Overall, September offers a tranquil yet refreshing respite, inviting visitors to relish both the beauty of Shirahama’s shores and the gentle caress of the sea breeze.

Average September Wind Speed in Shirahama

The chart displays monthly wind speed patterns in Shirahama, with values for each month shown alongside September's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how September's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec6.46.46.05.84.63.83.95.14.4 m/s4.95.46.5
Data source: Shirahama September wind data, generated using information from the Copernicus Climate Change Service.

How September Weather in Shirahama Compares to Other Months

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

In September, the weather is notably warmer, with average temperatures reaching 25°C (77°F) and highs climbing up to 30°C (86°F), while the humidity remains high at 82%. This month also experiences significant rainfall, accumulating to 239 mm (9.4 in) over an average of 16 days. In contrast, January brings a much cooler climate, with average temperatures plummeting to 8°C (47°F) and maximums of only 18°C (64°F). Precipitation is also lighter in January, totaling 77 mm (3.0 in) across just 9 days, accompanied by a moderate humidity level of 72%. For more details about Shirahama's weather in January, you can check out Shirahama weather in January.

September and February present striking contrasts in weather patterns. September boasts a warm average temperature of 25°C (77°F), with highs reaching up to 30°C (86°F), coupled with high humidity at 82%. In contrast, February experiences much cooler conditions, with an average temperature of only 8°C (47°F) and maximums around 18°C (65°F). While September sees considerable rainfall totaling 239 mm (9.4 in) over 16 days, February is markedly drier, accumulating just 98 mm (3.9 in) across 10 days. For more insights on February weather, check out Shirahama weather in February.

In September, the weather is notably warmer, with temperatures ranging from a minimum of 19°C (67°F) to a maximum of 30°C (86°F) and an average of 25°C (77°F). The month also experiences considerable rainfall, totaling 239 mm (9.4 in) over 16 days, alongside high humidity at 82%. In contrast, March brings much cooler conditions, with temperatures dipping down to a minimum of 4°C (39°F) and peaking at 19°C (66°F), averaging only 12°C (53°F). Precipitation in March is less intense, at 149 mm (5.9 in) over 11 days, with lower humidity levels at 69%. For more details, you can check Shirahama weather in March.

When comparing the weather in September and April, we see a striking contrast. September boasts warmer temperatures with a minimum of 19°C (67°F), averaging around 25°C (77°F), and reaching highs of 30°C (86°F). In contrast, April experiences much cooler conditions, with temperatures ranging from a minimum of 6°C (44°F) to a maximum of 21°C (70°F), averaging only 15°C (59°F). Additionally, September is significantly wetter, receiving 239 mm (9.4 in) of precipitation over 16 days, while April sees less rain at 148 mm (5.8 in) across just 10 days. The humidity is also higher in September at 82%, compared to 75% in April. For more specifics about April's weather, you can visit Shirahama weather in April.

September and May present distinct weather patterns, showcasing a notable difference in temperature and precipitation. September tends to be warmer, with average temperatures ranging from a minimum of 19°C (67°F) to a maximum of 30°C (86°F), while May sees cooler temperatures, with a range of 12°C (54°F) to 25°C (77°F). Additionally, September experiences more rainfall, with 239 mm (9.4 in) of precipitation over 16 days, compared to May's 203 mm (8.0 in) over just 10 days. Both months, however, share a common humidity level of 82%, contributing to a similar feel in the air. For a closer look at the weather patterns in May, you can check out Shirahama weather in May.

In comparing the weather between September and June, September tends to be warmer, with average temperatures reaching 25°C (77°F) compared to June's average of 22°C (72°F). The maximum temperature in September can rise to 30°C (86°F), while June peaks at a cooler 26°C (79°F). Both months experience similar levels of precipitation, with September receiving 239 mm (9.4 in) over 16 days and June close behind at 237 mm (9.3 in) over 14 days. Humidity is slightly lower in September at 82%, compared to June's 87%. For a more detailed look at June's climate, you can check out Shirahama weather in June.

When comparing the weather in September and July, September tends to be slightly cooler, with average temperatures ranging from a minimum of 19°C (67°F) to a maximum of 30°C (86°F), compared to July's warmer range of 21°C (71°F) to 31°C (88°F). Both months experience significant precipitation, but July sees a higher total of 353 mm (13.9 in) over 18 days, while September receives 239 mm (9.4 in) over 16 days. Humidity levels are also higher in July at 92%, compared to 82% in September, contributing to a more humid feel during the mid-summer month. For more detailed insights on July weather, you can visit Shirahama weather in July.

When comparing the weather in September to August, it’s evident that September experiences slightly cooler temperatures, with a minimum of 19°C (67°F) and an average of 25°C (77°F), compared to August's minimum of 22°C (73°F) and average of 27°C (81°F). Additionally, September sees more rainfall, with 239 mm (9.4 in) over 16 days, whereas August has slightly less precipitation at 227 mm (8.9 in) across 14 days. Humidity also remains high in both months, but it is marginally lower in September at 82%, compared to the 86% humidity typical of August. For more detailed information about August weather conditions, check out Shirahama weather in August.

September typically experiences warmer temperatures, with minimums around 19°C (67°F) and maximums peaking at 30°C (86°F). In contrast, October sees cooler conditions, with temperatures dropping to a minimum of 13°C (56°F) and a maximum of 27°C (81°F). While September is characterized by high humidity levels averaging 82% and significant rainfall totaling 239 mm (9.4 in) over 16 days, October has slightly lower humidity at 79% and increased precipitation, reaching 307 mm (12.1 in) during 13 days of rain. For a more detailed look at the weather patterns in October, you can visit Shirahama weather in October.

September and November present notably different weather patterns. In September, temperatures range from a minimum of 19°C (67°F) to a maximum of 30°C (86°F), with an average of 25°C (77°F). This month experiences significant rainfall, totaling 239 mm (9.4 in) over 16 days, combined with high humidity at 82%. In contrast, November brings cooler temperatures, with a minimum of 8°C (47°F) and a maximum of 23°C (73°F), averaging 16°C (61°F). The precipitation decreases dramatically to 72 mm (2.8 in) over just 7 days, and humidity drops to 75%. For a closer look at the weather specifics in November, visit Shirahama weather in November.

In September, the weather is notably warmer, with average temperatures around 25°C (77°F) and highs reaching up to 30°C (86°F). This month also experiences high humidity at 82% and significant rainfall, averaging 239 mm (9.4 in) over 16 days. In contrast, December brings a much cooler climate, with average temperatures dropping to 11°C (52°F) and a maximum of 20°C (69°F). Rainfall is also significantly reduced, totaling 85 mm (3.4 in) across just 9 days, and humidity lowers to 74%. For more details, you can visit Shirahama weather in December.

Compare Shirahama's Climate with Cities Worldwide

Conclusion: What to Expect From September Weather in Shirahama

As summer transitions into autumn in Shirahama, September brings a delightful blend of warmth and humidity, characterized by an average temperature hovering around 25°C (77°F). This month is notably more humid than the preceding summer months, with an average humidity of 82% that often results in frequent rain, totaling approximately 239 mm across about 16 days. Despite the increased precipitation, the warmth remains inviting, with highs reaching 30°C (86°F) and lows around 19°C (67°F), making it a unique time to experience the vibrant coastal scenery. For a more detailed understanding of how this month compares to others throughout the year, visit Shirahama Climate.