Last updated: August 21, 2025
In September, Kofu, Japan experiences a dynamic shift in weather, showcasing a maximum temperature of 30°C (86°F) and a comfortable average of 18°C (65°F). As the month progresses, temperatures can dip to a refreshing minimum of 8°C (47°F). This transitional period brings significant precipitation, with 183 mm (7.2 in) of rain spread across 18 days, contributing to an impressive humidity level of 86%. Embrace the lush landscapes and vibrant atmosphere that September offers, as Kofu's weather balances warmth and moisture, setting the stage for a captivating autumn ahead.
In Kofu, Japan, September marks a delightful transition from the sweltering summer to the cooler fall months. With minimum temperatures around 8°C (47°F) and a pleasant average of 18°C (65°F), days start to cool yet remain comfortably warm, with maximum temperatures reaching up to 30°C (86°F). This gentle drop in temperature is a refreshing change from the hot days of July and August, where highs soared to 32°C (90°F). As September unfolds, the city is often graced with clear skies and mild breezes, making it an ideal time for outdoor activities and enjoying the onset of autumn's vibrant colors.
September in Kofu, Japan, marks a notable transition in weather patterns, with precipitation reaching 183 mm (7.2 in) over 18 days. This increase reflects a shift from the drier summer months, as Kofu experiences a surge in rainfall that sets the stage for the autumn season. Following a relatively dry August, the September rains play a crucial role in replenishing local water sources, with precipitation during this month significantly exceeding figures from January to August. The uptick in both the amount and frequency of rainfall underscores a seasonal change, as Kofu prepares for the wetter months ahead, highlighted by the even higher precipitation levels anticipated in October.
In September, Kofu, Japan, experiences a notable humidity level of 86%, a significant drop from the peak months of July and August, which boast highs of 93% and 90%, respectively. This decline signals a gradual transition into autumn, where the air begins to feel slightly less oppressive yet remains comfortably moist. Throughout the year, humidity levels in Kofu show a clear pattern: starting at a high of 76% in January, they soar during the summer months before tapering off as the seasons change. The consistent fluctuations highlight Kofu's humid climate, particularly during the warmer months, making September a refreshing but still clingy month as the region begins to prepare for the cooler temperatures ahead.
As September rolls into Kofu, Japan, the UV Index begins to decline slightly from the peak summer months. With a UV Index of 10, this month falls into the very high exposure category, requiring a burn time of just 15 minutes for unprotected skin. This marks a transition from the extreme levels experienced in the previous summer months, yet caution is still advised. While outdoor activities remain inviting, it's essential to prioritize sun safety, especially as the days begin to shorten. For more detailed information on UV levels throughout the year, check out the insightful resource at Kofu UV Index.
UV Risk Categories
September in Kofu, Japan, continues the trend of warm and inviting days, boasting 238 hours of sunshine, which is slightly less than the 284 hours enjoyed in August but still represents a vibrant return from the summer heat. As the year transitions into autumn, the sun begins to soften, showcasing a gradual decline from the peak of 291 hours in May. The patterns indicate that Kofu remains blessed with abundant sunlight, especially noted in the spring months, while the gradual decrease into the fall sets a gentle tone for the upcoming cooler seasons. This delightful September sunlight serves as a perfect backdrop for early autumn activities, inviting residents and visitors alike to bask in the waning warmth before the winter chill sets in.
In September, Kofu, Japan experiences a 20% chance of sunny weather, signaling a decrease in clear skies as the region transitions into autumn. This aligns with the overall trend of diminishing sunlight during the summer months, which peak in July and August at 23%, followed by a notable drop as autumn approaches. Notably, the likelihood for sunshine rises again in October, reaching 43%, suggesting that while September may be less favorable for sun-seekers, the promise of sunnier days is just around the corner. The overall seasonal pattern reflects the dynamic nature of weather in Kofu, where cozy autumn days await after a balmy summer.
As summer gracefully transitions into autumn, September in Kofu, Japan offers a delightful 12 hours of daylight. This month marks a subtle decline from the balmy 14 hours enjoyed in June, July, and August, hinting at the approaching cooler months. The gradual decrease in daylight is characteristic of the shift from vibrant summer days towards the cozy, shorter daylight hours of fall. Observing the yearly pattern, daylight begins at a modest 10 hours in January and gradually peaks in late spring and summer, showcasing nature’s rhythmic cycle. September's balanced daylight invites residents to savor the lingering warmth of summer while preparing for the gentle embrace of autumn.
As September settles in Kofu, Japan, the average wind speed dips to 1.4 m/s (3 mph), continuing a trend of gentle breezes that has characterized the summer months. Following a steady decline from the spring's 1.9 m/s, the winds of September reflect a subtle transition towards autumn, marking a shift in the seasonal ambiance. This month’s calm winds offer a peaceful respite, allowing residents to enjoy the last warm days of the year while the leaves begin to hint at their change in color. In contrast to the slightly stronger gusts seen earlier in the year, including 2.1 m/s in February, September's soft breezes invite relaxation and contemplation as nature quietly prepares for the cooler months ahead.
Weather in Kofu varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Kofu, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January present starkly contrasting weather conditions. In September, temperatures range from a mild 8°C (47°F) at night to a warm average of 18°C (65°F), peaking at a hot 30°C (86°F) during the day. Rainfall is frequent with 183 mm (7.2 in) over 18 days, and the humidity is quite high at 86%, creating a sticky atmosphere. In contrast, January plunges into much colder temperatures, with nighttime lows of -16°C (3°F) and an average of -1°C (30°F), reaching a maximum of 11°C (52°F). Precipitation drops significantly to 48 mm (1.9 in) over just 6 days, and humidity decreases to 76%, contributing to a crisp, dry winter feel. For more details on the chilly conditions during this month, check out Kofu weather in January.
September and February present strikingly contrasting weather conditions. In September, temperatures can range from a chilly 8°C (47°F) at night to a warm 30°C (86°F) during the day, with an average of 18°C (65°F). This month experiences significant rainfall, totaling 183 mm (7.2 inches) across 18 days, accompanied by high humidity levels at 86%. In sharp contrast, February boasts much colder temperatures, with nighttime lows dropping to -12°C (10°F) and daytime highs peaking at 16°C (61°F), averaging around 0°C (32°F). Precipitation is less frequent in February, with only 60 mm (2.4 inches) falling over 7 days and humidity at a lower 74%. For more details on the weather in February, visit Kofu weather in February.
In September, the weather tends to be warmer, with temperatures ranging from a minimum of 8°C (47°F) to a maximum of 30°C (86°F) and an average around 18°C (65°F). The month is also characterized by high humidity at 86% and significant rainfall, totaling 183 mm (7.2 in) over 18 days. In contrast, March is much cooler, featuring temperatures between -6°C (21°F) and 20°C (68°F), with an average of just 4°C (40°F). While it experiences less rainfall at 136 mm (5.4 in) over 12 days, the humidity is lower at 70%. For a more detailed look at the weather during March, check out Kofu weather in March.
September and April present notably different weather patterns. In September, temperatures range from a cool 8°C (47°F) at night to a warm 30°C (86°F) during the day, with an average of 18°C (65°F). This month also experiences considerable rainfall, with 183 mm (7.2 in) of precipitation over 18 days and high humidity at 86%. In contrast, April sees cooler temperatures, with a minimum of -5°C (23°F) and a maximum of 25°C (77°F), averaging around 9°C (48°F). This month is drier, with 129 mm (5.1 in) of precipitation across 13 days and a lower humidity level of 74%. For more detailed insights on the conditions in April, check out Kofu weather in April.
When comparing the weather in September and May, several notable differences emerge. September generally experiences warmer temperatures, with a minimum of 8°C (47°F) and an average of 18°C (65°F), peaking at 30°C (86°F). In contrast, May starts cooler, with minimums dropping to 0°C (33°F) and averages around 14°C (58°F), but still reaching highs of 28°C (84°F). Additionally, September tends to be wetter, receiving 183 mm (7.2 in) of precipitation over 18 days, compared to May's 138 mm (5.4 in) over just 13 days. Humidity levels are also slightly higher in September at 86%, compared to 81% in May. For more details about Kofu's weather in May, check out Kofu weather in May.
September and June exhibit relatively mild temperatures, with September showing a slightly wider temperature range. In September, temperatures fluctuate from a minimum of 8°C (47°F) to a maximum of 30°C (86°F), averaging around 18°C (65°F). In contrast, June has a slightly cooler range, with minimum temperatures at 6°C (43°F) and maximums reaching 28°C (83°F), with an average of 17°C (64°F). September also experiences higher precipitation at 183 mm (7.2 in) over 18 days, compared to June's 147 mm (5.8 in) over 16 days. Both months have high humidity levels, September at 86% and June at 88%, making the air feel quite damp. For more details on June weather, you can check this link: Kofu weather in June.
In comparing the weather between July and September, it's evident that July tends to be warmer overall, with temperatures ranging from a minimum of 13°C (56°F) to a maximum of 32°C (90°F) and an average of 21°C (70°F). In contrast, September experiences a broader range of temperatures, dipping as low as 8°C (47°F) at night, but it can still reach up to 30°C (86°F) during the day, with an average temperature of 18°C (65°F). Additionally, July sees higher rainfall, totaling 293 mm (11.6 in) over 20 days, compared to September's 183 mm (7.2 in) over 18 days. Humidity levels are also higher in July at 93%, compared to 86% in September. For more detailed insights, you can check Kofu weather in July.
In comparing the weather of September to that of August, September experiences slightly cooler temperatures, with a minimum of 8°C (47°F) and an average of 18°C (65°F), compared to August's minimum of 12°C (54°F) and an average of 23°C (73°F). Although both months share a similar number of rainy days, September sees increased precipitation, totaling 183 mm (7.2 in) compared to August's 150 mm (5.9 in). Additionally, the humidity slightly decreases in September to 86%, down from August's 90%. For more details about the weather in August, you can visit Kofu weather in August.
September tends to be warmer with average temperatures ranging from a low of 8°C (47°F) to a high of 30°C (86°F). It also experiences significant rainfall, totaling 183 mm (7.2 in) over 18 days, alongside relatively high humidity at 86%. In contrast, October sees a notable drop in temperatures, with averages between 1°C (35°F) and 26°C (79°F). Despite this decrease, rainfall increases to 277 mm (10.9 in) over 17 days, and humidity slightly decreases to 83%. For more details, visit Kofu weather in October.
September offers a much warmer climate compared to November, with average temperatures ranging from a mild 18°C (65°F) to a peak of 30°C (86°F). In contrast, November sees a significant drop in temperatures, with averages only reaching around 7°C (45°F) and nighttime lows plummeting to -4°C (25°F). Additionally, September experiences higher precipitation, with 183 mm (7.2 in) recorded over 18 days, while November's rainfall is lighter, totaling 52 mm (2.0 in) across just 8 days. Humidity levels are slightly higher in September at 86%, compared to 80% in November. For more detailed insights, check out Kofu weather in November.
In September, the weather is generally warmer and more humid, with average temperatures around 18°C (65°F) and a maximum of 30°C (86°F). The month sees significant precipitation, totaling 183 mm (7.2 in) over 18 days, resulting in a humidity level of 86%. In contrast, December brings much colder temperatures, with an average of 1°C (35°F) and a maximum of 17°C (63°F). Rainfall is also significantly reduced, with only 54 mm (2.1 in) over just 7 days and a lower humidity of 78%. For more specific details on December conditions, you can check Kofu weather in December.
As summer transitions to autumn, September in Kofu brings a delightful change in weather dynamics. With temperatures averaging around 18°C (65°F), the month offers a comfortable escape from the sweltering heat, making way for more refreshing days. However, September is also characterized by increased rainfall, with nearly 18 days experiencing precipitation, contributing to a notable humidity level of 86%. This combination of milder temperatures and higher moisture creates a unique atmosphere that contrasts sharply with the drier and hotter months of July and August. For a deeper exploration of the patterns that define Kofu's climate, visit Kofu Climate.