Last updated: August 21, 2025
In Kusatsu, Japan, September ushers in a blend of warmth and moisture, characterized by maximum temperatures soaring up to 35°C (96°F) and an average of 24°C (75°F). As the month progresses, conditions can shift, with minimum temperatures dropping to a comfortable 14°C (57°F). Despite the inviting warmth, Kusatsu experiences significant rainfall, accumulating around 136 mm (5.4 in) over 13 days, contributing to a lush, green landscape. With an average humidity level of 87%, visitors should be prepared for a slightly sticky atmosphere, typical of early autumn in this picturesque Japanese town.
In September, Kusatsu, Japan, experiences a distinct shift in temperatures, signaling the transition from the sweltering summer to the cooler autumn months. With minimum temperatures rising to a mild 14°C (57°F) and average highs peaking at a warm 35°C (96°F), the weather still holds onto the vestiges of summer heat. However, as the month progresses, the average temperature stabilizes around 24°C (75°F), inviting visitors to enjoy the pleasant climate. This gradual decline towards cooler evenings contrasts sharply with the preceding months of July and August, where sweltering highs reached close to 38°C (101°F). September serves as a beautiful bridge, blending the warmth of summer with the crisp promise of autumn, making it an ideal time to explore Kusatsu’s stunning landscapes and rich culture.
In September, Kusatsu experiences a notable decline in precipitation compared to the summer months, with 136 mm (5.4 in) falling over 13 days. This marks a shift from the heavy rains of July and August, where the city sees its peak precipitation levels. Instead, September presents a more moderate but consistent pattern, hinting at the transition into autumn. The rainfall is ample enough to nourish the lush landscape yet less intense, allowing for clearer days that invite outdoor activities. As temperatures begin to cool, this balance of wet and dry days makes September a unique time in Kusatsu, blending the remnants of summer with the early whispers of fall.
In September, Kusatsu, Japan, experiences a noticeable transition as humidity levels settle at a comfortable 87%. This maintains the high humidity trend seen throughout the summer months, particularly during the sweltering July and August, which peaked at 93% and 91% respectively. Following the vibrant, moisture-laden months of June through August, September's humidity begins to hint at the upcoming cooler months, while still being higher than the year's earlier months. As the season shifts, the humidity starts to gradually decrease, setting the stage for October's 85%, but September remains a reminder of the lingering warmth and richness of summer in this picturesque locale.
In September, Kusatsu, Japan, experiences a UV Index of 10, categorizing it as very high and requiring caution for sun exposure. As summer wanes, this index remains slightly lower than the peak months of June to August, which consistently recorded extreme levels of 11. Interestingly, the burn time increases to 15 minutes, suggesting that while the sun’s intensity is still significant, the risk of harm is somewhat reduced compared to the heights of summer. This trend reflects a gradual transition towards milder conditions, as the UV Index dips further to 7 in October. For those planning outdoor adventures, it’s essential to stay informed about daily UV levels for safe sun exposure. For more details, check out the Kusatsu UV Index.
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As September graces Kusatsu, Japan, the town enjoys a delightful 232 hours of sunshine, a warm embrace before the chill of autumn sets in. This month, though slightly less radiant than the sun-drenched days of August with its peak of 292 hours, still stands out with a cloudless sky that offers a milder respite compared to the previous summer months. A gradual decline in sunshine can be observed as the year progresses, transitioning from the 282 hours in May to the early glimpse of winter with 211 hours in December. However, September maintains a comfortable balance, echoing the transitions in nature and inviting visitors to savor the lingering warmth and vibrant autumn colors that define this season in Kusatsu.
In Kusatsu, Japan, September brings a modest 26% chance of sunny weather, reflecting a subtle shift as autumn approaches. This figure sits slightly above the low points of summer, like June and August, which experience even less sunshine, suggesting that while the days may begin to cool, there’s still a chance for pleasant moments under the sun. As the month progresses, the trend begins to pick up again in October, climbing to 48%, making fall an ideal time for outdoor activities following the mild September days. Overall, while September's sunny moments may be limited, they offer a refreshing transition into the vibrant hues of autumn.
In Kusatsu, Japan, the rhythms of daylight duration reflect the changing seasons, peaking at 14 hours during the height of summer in June and July. As September rolls in, daylight begins to wane slightly, offering 12 hours of sunlight—a gentle transition into the cooler months. Following September, daylight diminishes more notably in October and November, settling to 10 hours by late fall and dipping to a cozy 9 hours in December. This gradual reduction from summer's abundance to winter's scarcity not only emphasizes the beauty of seasonal change but also invites residents and visitors to relish every moment of the day's light as the year draws to a close.
In September, the wind in Kusatsu, Japan, maintains a gentle flow, averaging around 2.3 m/s (5 mph). This month marks a subtle transition as the wind speeds echo the calmness of late summer; they remain consistently low, mirroring the patterns established in the preceding months of June and July. As autumn approaches, wind speeds begin to gradually increase, hinting at the seasonal shift to come, but September itself retains a serene quality. The persistent light breezes are ideal for outdoor activities and leisurely walks, making it a delightful time to experience the natural beauty of Kusatsu while enjoying the mild winds that whisper through the landscape.
Weather in Kusatsu varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Kusatsu, focusing on differences in temperature, rainfall, humidity, and UV levels.
September and January offer contrasting weather experiences. In September, temperatures are much warmer, with a minimum of 14°C (57°F) and an average of 24°C (75°F), peaking at a sweltering 35°C (96°F). This month is also quite wet, accumulating 136 mm (5.4 in) of precipitation over 13 days and featuring high humidity at 87%. In stark contrast, January brings a chill, with temperatures dropping to a minimum of -7°C (20°F), averaging just 4°C (39°F), and reaching a maximum of 15°C (60°F). Precipitation is significantly lower, at 52 mm (2.0 in) over 8 days, and the humidity is slightly less at 82%. For more details on the January conditions, you can check Kusatsu weather in January.
September and February present contrasting weather patterns. In September, temperatures range from a minimum of 14°C (57°F) to a scorching maximum of 35°C (96°F), with an average of 24°C (75°F). The month sees significant rainfall, totaling 136 mm (5.4 in) over 13 days, accompanied by high humidity levels reaching 87%. In stark contrast, February experiences much cooler conditions, with temperatures dipping to a minimum of -6°C (21°F) and averaging just 5°C (41°F), peaking at 19°C (67°F). Precipitation is less frequent, accumulating 59 mm (2.3 in) across 8 days, and humidity is slightly lower at 79%. This clear divergence in temperature and precipitation patterns makes each month distinctly different. For more information on February's climate, you can visit Kusatsu weather in February.
September and March present contrasting weather patterns. September features warmer temperatures, with lows of 14°C (57°F), average highs reaching 24°C (75°F), and the potential for maximum temperatures soaring to 35°C (96°F). In contrast, March experiences cooler conditions, where temperatures can dip as low as -3°C (27°F), with an average of 9°C (49°F) and highs capping at 23°C (73°F). Both months see significant precipitation, with September receiving about 136 mm (5.4 in) over 13 days and March having 116 mm (4.6 in) across 11 days. The humidity in September is notably higher at 87%, compared to March's more moderate 74%. For a detailed view of weather conditions specific to March, you can refer to this link: Kusatsu weather in March.
September and April present contrasting weather conditions, each offering a unique experience. In September, temperatures range from a minimum of 14°C (57°F) to a maximum of 35°C (96°F), creating a warm and humid atmosphere with an average temperature of 24°C (75°F) and 87% humidity. The month sees substantial rainfall, with precipitation of 136 mm (5.4 in) over 13 days. In contrast, April features cooler temperatures, with a minimum of -1°C (31°F) and a maximum of 27°C (80°F), resulting in an average of 14°C (57°F). While April has a similar level of precipitation at 138 mm (5.4 in), it occurs over 10 days, accompanied by lower humidity at 76%. For more detailed insights, you can check Kusatsu weather in April.
September and May exhibit distinct weather patterns, with September generally being warmer and more humid. In September, temperatures range from a minimum of 14°C (57°F) to a maximum of 35°C (96°F), while May presents a cooler range with temperatures from 6°C (43°F) to 32°C (89°F) and an average of 19°C (66°F). Both months see significant rainfall, with September receiving 136 mm (5.4 in) over 13 days, compared to May's 144 mm (5.7 in) over just 11 days. The humidity is slightly higher in September at 87% compared to May's 83%. For more details on the weather in May, check out this link: Kusatsu weather in May.
In comparing the weather of September and June, both months exhibit a high level of humidity at 87%, contributing to a sultry atmosphere. September tends to be slightly warmer, with average temperatures around 24°C (75°F) and maximums reaching up to 35°C (96°F), while June's averages are a bit cooler at 22°C (72°F) with max temperatures of 32°C (90°F). Precipitation levels are quite similar, with September receiving 136 mm (5.4 in) over 13 days and June seeing 141 mm (5.6 in) across 12 days. For more insights on June weather in Kusatsu, you can check Kusatsu weather in June.
September weather tends to be milder compared to July, with average temperatures ranging from a minimum of 14°C (57°F) to a maximum of 35°C (96°F), while July sees higher temperatures, with a minimum of 19°C (66°F) and a peak of 37°C (98°F). Precipitation levels in September are also lower at 136 mm (5.4 in) over 13 days, in contrast to July's heavier rainfall of 253 mm (10.0 in) across 19 days. Additionally, September's humidity at 87% is slightly lower than July’s more humid conditions at 93%. For a detailed overview of July weather, you can visit Kusatsu weather in July.
In comparing the weather between August and September, September tends to be slightly cooler, with average temperatures ranging from a minimum of 14°C (57°F) to a maximum of 35°C (96°F), compared to August's warmer range of 18°C (65°F) to 38°C (101°F). Additionally, September experiences a decrease in humidity levels to 87%, down from August's higher humidity of 91%. Precipitation in September is also lower at 136 mm (5.4 in) over 13 days, compared to August's 168 mm (6.6 in) over 12 days. For more details on August weather, you can refer to Kusatsu weather in August.
In September, temperatures range from a minimum of 14°C (57°F) to a maximum of 35°C (96°F), with an average of 24°C (75°F). The month is characterized by significant rainfall, totaling 136 mm (5.4 in) across 13 days, combined with high humidity levels at 87%. In contrast, October experiences cooler weather, with temperatures dropping to a minimum of 7°C (45°F) and peaking at 33°C (92°F), averaging at 18°C (65°F). The precipitation increases to 227 mm (8.9 in) over the same number of rainy days, while humidity remains relatively stable at 85%. This shift marks a transition from the warmer, wetter conditions of September to the cooler, wetter climate of October. For more details, you can check Kusatsu weather in October.
September weather tends to be much warmer, with average temperatures around 24°C (75°F) and maximums reaching up to 35°C (96°F). This month also experiences significant rainfall, totaling 136 mm (5.4 in) over about 13 days, along with high humidity levels at 87%.
In contrast, November brings a noticeable drop in temperatures, with averages around 12°C (54°F) and a maximum of 25°C (77°F), making it considerably cooler. Precipitation decreases to just 41 mm (1.6 in) over only 5 days, alongside slightly lower humidity at 83%. For more detailed information about the weather during this month, you can check Kusatsu weather in November.
September and December present distinctly different weather patterns. In September, temperatures range from a min of 14°C (57°F) to a scorching max of 35°C (96°F), with an average of 24°C (75°F), making it the last vestiges of summer warmth. The month is characterized by high humidity at 87% and significant precipitation, totaling 136 mm (5.4 in) over 13 days. In contrast, December brings a marked drop in temperatures, with a minimum of -7°C (19°F) and an average of 6°C (44°F), peaking at a more temperate 22°C (72°F). Precipitation decreases to 63 mm (2.5 in) across 8 days, and humidity slightly drops to 83%. The transition from the warm, humid days of September to the cold, crisp conditions of December showcases the dramatic seasonal change. For a more detailed look at December's weather, you can visit Kusatsu weather in December.
As the warm summer days gradually give way to autumn, September in Kusatsu presents a unique blend of weather characteristics that distinguish it from other months. With maximum temperatures peaking around 35°C, the heat lingers, yet a noticeable drop to cooler evenings invites a refreshing respite. This month is also marked by significant precipitation, contributing to its lush landscapes, and an elevated humidity level that enhances the feeling of warmth. Unlike the dry months preceding it, the 13 days of rain bring a sense of renewal to the area, highlighting the transition towards the crispness of fall. For more detailed insights into Kusatsu's weather patterns, check out the Kusatsu Climate page.