Last updated: August 21, 2025
September in Suwa, Japan, presents a delightful blend of warm temperatures and refreshing rainfall. The maximum temperature peaks at a pleasant 30°C (86°F), while the average hovers around 19°C (66°F), providing a comfortable climate for outdoor activities. However, temperatures can dip to a cool 6°C (42°F), particularly in the evenings. This month sees about 171 mm (6.7 in) of precipitation spread across 16 days, which contributes to the city's lush scenery. With an humidity level of 86%, the air is notably rich, enhancing the crispness after rain showers and creating a unique atmosphere that is both invigorating and refreshing.
September in Suwa, Japan, ushers in a delightful transition as summer begins to wane. With minimum temperatures around 6°C (42°F) and a comfortable average of 19°C (66°F), the month offers a refreshing respite from the intense heat of August. Highs can even reach a pleasant 30°C (86°F), allowing for plenty of opportunities to enjoy the lingering warmth. As the air grows crisper and the leave colors begin to shift, September showcases a harmonious blend of late summer vibrancy and early autumn calm, making it an ideal time for outdoor activities and appreciating the scenic beauty of the region.
In September, Suwa, Japan experiences a significant transition in its weather patterns, marked by a precipitation amount of 171 mm (6.7 in) over approximately 16 rainy days. This represents a notable increase compared to the drier months that precede it, particularly August, which recorded 151 mm (5.9 in) with 16 days of rain. As summer gives way to autumn, the wet conditions signal the onset of a more persistent rainfall pattern leading into October, which typically sees even greater totals. The consistency in rainfall days during September aligns with this trend of increasing moisture, capturing the shift in climate as the region prepares for the coming cold months. The gradual rise in precipitation from summer into autumn underscores Suwa’s dynamic weather patterns, which are crucial for the region’s agriculture and local ecosystems.
As the summer months fade, September in Suwa, Japan, showcases a notable drop in humidity compared to the sweltering peak of July at 93% and August at 90%. With humidity settling at 86%, the air is still undeniably moist, but it hints at the transition towards autumn. This month stands out as a bridge where the warmth of summer lingers, yet the numbers indicate a gradual decrease, reminiscent of the 81% humidity seen in May. Following a trend of rising humidity from late spring through summer, September serves as a gentle reminder of the changing seasons, setting the stage for the cooler and drier months ahead.
In September, Suwa, Japan experiences a UV Index of 10, marking it as a month of very high exposure. This trend reflects a slight decrease from the peak extreme levels seen in July and August, where the UV Index reached a maximum of 12. The burn time for unprotected skin in September is 15 minutes, underscoring the importance of sun protection as summer transitions to autumn. The overall pattern shows a gradual shift from extreme UV levels in the summer months to high and moderate levels as the year progresses, making it crucial for residents and visitors alike to stay vigilant about sun safety. For detailed information on UV exposure, check out Suwa UV Index.
UV Risk Categories
September in Suwa, Japan, brings a refreshing touch of sunlight with 239 hours of bright days. As summer's warmth gradually fades, this month stands out as a bridge between the vibrant energy of August, which boasts the highest sunshine at 285 hours, and the mellow tones of October, featuring 223 hours. The consistent pattern of sunshine throughout the year is evident, with the spring months peaking in brightness—March and May enjoying their share at 268 and 292 hours, respectively. However, as autumn approaches, sunlight begins to retreat, showcasing a gradual decline towards winter. This captivating transition in Suwa not only enhances the beauty of the landscape but also invites reflection and serenity during the picturesque September days.
As September rolls in, Suwa, Japan, experiences a noticeable dip in sunny days, with a 22% chance of sunshine. This marks one of the year's lowest probabilities, reflecting a shift from the warmer summer months of July and August, which also feature limited sun exposure at 32% and 24% respectively. The trend indicates that as the seasons change, the likelihood of clear skies tends to increase again in October, reaching 44%. Thus, while September may bring a bit of gloom, the promise of brighter days is just around the corner as autumn takes hold.
As September unfolds in Suwa, Japan, the daylight duration is a gentle reminder that summer is transitioning into autumn, offering 12 hours of daylight. This month serves as a bridge, following the lush 14 hours enjoyed in the summer's peak of June, July, and August. As daylight begins to wane, Suwa experiences a gradual decline, with hours decreasing as the year progresses into October and November. The trend illustrates a consistent pattern: longer days from January through September, culminating in a gradual retreat back to the 9 hours of daylight by December. This cyclical dance of light not only marks the changing seasons but also enriches the beautiful landscape of Suwa, providing a captivating backdrop for both daily activities and seasonal celebrations.
In September, the gentle breeze in Suwa, Japan, wraps around the vibrant city with an average wind speed of 1.4 m/s (3 mph), reflecting a continuation of the subtle calm experienced throughout the summer months. As autumn approaches, this marks a slight decrease from the more moderate winds of the earlier seasons, particularly after the 2.1 m/s (5 mph) of May and June. Completing a tranquil transition, September's winds offer a soothing ambiance, consistent with the overall trend observed from July to October, where wind speeds remain relatively subdued. This graceful shift beckons locals and visitors alike to savor the serene beauty of the changing season, enveloped in the soft embrace of Suwa’s September air.
Weather in Suwa varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Suwa, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present strikingly different weather conditions. In September, temperatures range from a mild 6°C (42°F) to a warm 30°C (86°F), with an average of 19°C (66°F). This month also sees significant rainfall, totaling 171 mm (6.7 in) spread over 16 days, combined with high humidity levels at 86%. In stark contrast, January is characterized by colder conditions, with temperatures ranging from a frigid -18°C (0°F) to a maximum of 12°C (53°F), averaging -2°C (29°F). The precipitation drops to 75 mm (3.0 in) over 12 days, and the humidity decreases to 76%. For more details, check out Suwa weather in January.
September and February showcase remarkable contrasts in weather. In September, temperatures range from a mild 6°C (42°F) at night to a warm average of 19°C (66°F), peaking at a high of 30°C (86°F). The month also experiences significant rainfall, with 171 mm (6.7 in) of precipitation over 16 days and a high humidity level of 86%. In stark contrast, February offers much colder conditions, with nighttime temperatures plunging to -18°C (0°F) and an average of -1°C (30°F), reaching a maximum of 15°C (60°F). Additionally, February sees less precipitation, totaling 80 mm (3.2 in) over 10 days, with humidity levels at a lower 74%. For more detailed insights, check Suwa weather in February.
In September, the weather is typically warmer, with temperatures ranging from a minimum of 6°C (42°F) to a maximum of 30°C (86°F) and an average of 19°C (66°F). The month experiences significant precipitation, totaling 171 mm (6.7 in) across approximately 16 days, accompanied by high humidity levels of 86%. In contrast, March heralds the arrival of spring with cooler temperatures, where lows can dip to -7°C (19°F) and highs reach 20°C (68°F), averaging around 4°C (40°F). Precipitation is slightly lower at 141 mm (5.6 in), occurring over about 12 days, and the humidity is reduced to 70%. For more detailed weather patterns, you can visit Suwa weather in March.
The weather in September is notably warmer than in April, with average temperatures reaching 19°C (66°F) compared to April's 9°C (48°F). September experiences a wider temperature range, with highs soaring up to 30°C (86°F), while April's maximum temperature caps at 26°C (78°F). In terms of precipitation, September is wetter with 171 mm (6.7 in) spread over 16 days, contrasting with April's 143 mm (5.6 in) over 13 days. Additionally, September maintains a higher humidity level at 86%, compared to April’s 74%. For more details on April weather, you can visit Suwa weather in April.
When comparing the weather in September and May, we see notable differences. September boasts a wider temperature range, with minimums of 6°C (42°F) and highs reaching up to 30°C (86°F), while May starts off cooler, with minimums dipping down to -1°C (31°F) but also enjoying pleasant highs of 29°C (85°F). Precipitation is slightly higher in September at 171 mm (6.7 in) over 16 days compared to May's 155 mm (6.1 in) over 12 days. Humidity levels are higher in September at 86%, whereas May has a more comfortable 81%. For a closer look at May weather specifics, you can check Suwa weather in May.
When comparing September and June weather, both months offer a range of temperatures and humidity, though September is slightly warmer. In September, temperatures range from a minimum of 6°C (42°F) to a maximum of 30°C (86°F), averaging 19°C (66°F), while June's temperatures span from 5°C (41°F) to 29°C (84°F), with an average of 18°C (65°F). Additionally, September sees more precipitation, with 171 mm (6.7 in) over 16 days, compared to June's 149 mm (5.8 in) over 14 days. Humidity levels are fairly high in both months, with September at 86% and June slightly higher at 88%. For more details on June weather, you can visit Suwa weather in June.
In comparing the weather between September and July, notable differences emerge. September experiences a wider temperature range, with minimums dipping to 6°C (42°F) and maximums reaching up to 30°C (86°F), averaging 19°C (66°F). In contrast, July remains warmer with minimum temperatures of 14°C (58°F) and highs hitting 33°C (91°F), averaging a comfortable 22°C (72°F). Precipitation also varies significantly; September sees 171 mm (6.7 in) over 16 days, while July is notably wetter with 289 mm (11.4 in) spread across 19 days. Humidity levels are higher in July at 93%, compared to September's 86%. For more specific details on July's conditions, you can check out Suwa weather in July.
In September, the weather is noticeably cooler than in August, with minimum temperatures dropping to 6°C (42°F) compared to 12°C (53°F) in August. The average temperature in September is 19°C (66°F), while August remains warmer at an average of 23°C (74°F). Although both months experience precipitation on 16 days, September sees a slight increase in total rainfall with 171 mm (6.7 in) compared to August's 151 mm (5.9 in). Humidity levels are also slightly lower in September at 86%, compared to 90% in August, indicating a shift towards a more comfortable feel as summer ends. For more detailed insights, check out Suwa weather in August.
September and October present a notable shift in weather patterns. In September, temperatures range from a cool minimum of 6°C (42°F) to a warm maximum of 30°C (86°F), with an average of 19°C (66°F). The month sees significant rainfall, totaling 171 mm (6.7 in) over 16 days, coupled with high humidity at 86%. Conversely, October experiences cooler conditions, with temperatures dipping from a minimum of 0°C (33°F) to a maximum of 26°C (79°F) and an average of 13°C (56°F). Rainfall increases to 237 mm (9.3 in), still spread over 16 days, while humidity slightly decreases to 83%. For more details on October weather, visit Suwa weather in October.
September and November exhibit notably different weather patterns. In September, temperatures range from a minimum of 6°C (42°F) to a maximum of 30°C (86°F), with an average of 19°C (66°F). The month is characterized by high humidity at 86% and considerable rainfall, accumulating 171 mm (6.7 in) over 16 days. In stark contrast, November sees a drop in temperatures, with a minimum of -4°C (25°F), an average of 7°C (44°F), and a maximum of 18°C (65°F). Precipitation is also lighter in November, totaling 66 mm (2.6 in) over just 10 days and a lower humidity level of 80%. For more detailed information, visit Suwa weather in November.
In September, the weather is significantly warmer, with average temperatures around 19°C (66°F) and maxima reaching up to 30°C (86°F), while the minimum can dip to 6°C (42°F). With 171 mm (6.7 in) of precipitation spread across 16 days, the month tends to be quite humid, averaging 86%. In stark contrast, December brings a notable chill, featuring a much lower average temperature of 1°C (34°F) and maxima of 16°C (62°F), with a minimum that can plunge to -9°C (16°F). This month experiences relatively less rainfall, with 84 mm (3.3 in) over just 12 days and a humidity level of 78%. For more detailed information, you can check out Suwa weather in December.
September in Suwa marks a transition towards cooler temperatures and a noticeable increase in humidity, setting it apart from the warmer summer months. With an average temperature of 19°C (66°F), this month is characterized by mild days and cooler nights, providing a refreshing reprieve from the heat. However, the significant precipitation of 171 mm over roughly half the month contributes to a lush and vibrant landscape. The increased rainfall and higher humidity create a unique atmosphere, hinting at the approach of autumn while still offering occasional warm days. For a deeper understanding of Suwa's overall climate throughout the year, visit Suwa Climate.