Last updated: August 21, 2025
In August, Unzen, Japan experiences a tropical climate marked by soaring temperatures, with maximums reaching up to 39°C (102°F) and an average around 29°C (85°F). The warmth is often accompanied by high humidity levels, averaging a steep 91%, making the air feel even more sultry. Rainfall is frequent, with nearly 303 mm (11.9 in) accumulated over 14 days, providing much-needed relief amid the heat. Visitors should prepare for a blend of vibrant summer days and sudden showers, capturing the essence of this unique Japanese locale during the peak of summer.
In August, Unzen, Japan, experiences its hottest temperatures of the year, with minimums holding steady at 20°C (68°F) and averages soaring to 29°C (85°F). This month sees the mercury peak at a sweltering 39°C (102°F), marking a significant uptick from the summer heat that begins in July. The transition from the cooler, more mild months of spring into the intense summer underscores the dramatic shift in climate, where average temperatures jump from 27°C (82°F) in July to the balmy August highs. As autumn approaches, the heat starts to dissipate, but August stands out as a time when the sun's rays are at their strongest, inviting locals and travelers alike to savor the season's warmth amidst Unzen's beautiful landscapes.
In August, Unzen experiences a notable decline in precipitation compared to the previous month, with 303 mm (11.9 in) of rainfall over 14 days. This marks a significant drop from July's record high of 475 mm (18.7 in), highlighting a mid-summer transition in weather patterns. Despite the decrease, August still ranks as one of the wettest months, continuing a trend initiated in the earlier summer months of June and July. As the peak rain season winds down, residents can expect more manageable weather, yet conditions remain ripe for the lush greenery that characterizes this picturesque region of Japan.
In Unzen, Japan, the humidity experiences a gradual climb as the year progresses, peaking with the summer months' sweltering embrace. Starting at a relatively moderate 75% in January, humidity levels rise steadily, reaching 91% in August. This is just a slight dip from the July high of 92%, showcasing the region's characteristic moist summer climate. Following August, humidity begins to decline, dipping to 84% in September as the transition to the cooler autumn months begins. Overall, the trend highlights a pattern of escalating humidity during the warmer season, underscoring Unzen's lush and vibrant environment, particularly in the heart of summer.
In August, Unzen experiences the peak of its UV index, reaching an astonishing 12, which falls into the extreme exposure category. This consistent high level of UV radiation during the summer months underscores the importance of sun safety, as the burn time is reduced to just 10 minutes. Following this trend, both July and September also showcase elevated UV readings of 12 and 11 respectively, maintaining a steady demand for protective measures against harmful rays. As the year progresses, UV indices range from 4 in January to a mild 7 by October, illustrating a noticeable fluctuation in sun intensity throughout the seasons. For more detailed information on UV levels and to better plan your sun exposure, visit Unzen UV Index.
UV Risk Categories
In August, Unzen basks in the glow of 300 hours of sunshine, marking the peak of summer and illuminating the landscape with vibrant hues. This abundant sunshine is a delightful contrast to the colder months, where daylight hours dwindle significantly. Observing the trends, we see a steady increase from January's modest 180 hours, gradually building up through the spring months, culminating in August's radiant burst. Following August, the sun still graces Unzen with over 250 hours of sunshine in September and October, but the light begins to retreat as the year winds down. This annual rhythm of sunshine not only enriches Unzen's scenic beauty but also invites visitors to savor the warmth and splendor of summer.
In August, the likelihood of sunny weather in Unzen, Japan, dips to 27%, reflecting a notable trend of decreasing sunshine as summer wanes. After the peak sunny months of early spring, where chances hovered around the low 40s, the summer months see a decline, with July and June recording even lower probabilities of sunlight at 20% and 21% respectively. This pattern suggests that as the hot season progresses, the weather tends to become more humid and cloudy, setting the stage for the impressive shift in October when the chance of sun rises significantly to 64%. Travelers looking to experience sunshine should consider these seasonal transitions, as August offers just a glimpse of the brighter days that follow.
In Unzen, Japan, the rhythm of daylight duration reflects the changing seasons beautifully. August sees daylight lasting 13 hours, a delightful continuation of the summer's longer days, though it marks a gradual decline from the peak of 14 hours experienced in both June and July. As summer transitions into autumn, daylight begins its steady retreat, dwindling to 12 hours in September. This trend underscores a serene cycle of light and dark, where each month invites both residents and visitors to embrace the unique charm of Unzen's natural landscape.
In Unzen, Japan, the wind patterns shift subtly throughout the year, creating a gentle breeze that characterizes each season. January begins with an average speed of 3.0 m/s, reflecting the winter chill, but as the months progress, the winds gradually soften, hitting their lowest in June at just 1.6 m/s. The summer months see a slight rise, with August stabilizing at 2.7 m/s, providing a mild and pleasant atmosphere. As autumn approaches, the winds slightly decline again, averaging 2.3 m/s in September. This dynamic trend reveals a rhythmic dance of breezes influenced by seasonal changes, inviting visitors to experience the tranquil charm of Unzen year-round.
Weather in Unzen varies notably across the year, with each month offering distinct climate conditions. This page compares August’s weather to other months in Unzen, focusing on differences in temperature, rainfall, humidity, and UV levels.
August and January present stark contrasts in weather. August typically boasts warm temperatures, with a minimum of 20°C (68°F) and an average high of 29°C (85°F), reaching peaks of up to 39°C (102°F). This month is characterized by high humidity levels at 91% and significant rainfall, averaging 303 mm (11.9 in) over 14 days. In contrast, January experiences much cooler conditions, with temperatures dipping as low as -2°C (29°F) and averaging just 8°C (46°F), reaching a maximum of 19°C (66°F). Precipitation in January is considerably less, at 53 mm (2.1 in), across only 6 days, and the humidity is lower at 75%. For more detailed information, you can check Unzen weather in January.
August offers a stark contrast to February in terms of temperature and humidity. With average highs reaching up to 29°C (85°F) and even maxing out at 39°C (102°F), August is characterized by a warm and humid climate, with humidity levels soaring to 91% and nearly half of the month experiencing rainfall (14 days, totaling 303 mm). On the other hand, February brings a much cooler and drier atmosphere, featuring average temperatures of around 8°C (48°F) and maximums that cap at 22°C (71°F). This month experiences significantly less rainfall, with only 92 mm accumulating over 9 days and a lower humidity level of 71%. To learn more about the specific weather patterns in February, you can visit Unzen weather in February.
When comparing the weather in August and March, significant differences are evident. August boasts a much warmer climate, with temperatures ranging from a minimum of 20°C (68°F) to a scorching maximum of 39°C (102°F), while March experiences cooler temperatures, peaking at 24°C (76°F) and averaging just 12°C (55°F). Additionally, August is characterized by high humidity levels at 91% and considerable rainfall, recording 303 mm (11.9 in) over 14 days, in contrast to March's relatively mild humidity of 71% and lower precipitation of 145 mm (5.7 in) over 11 days. Overall, August presents a hot and humid season, while March offers a cooler and drier climate. For more detailed information about March weather, visit Unzen weather in March.
In August, the weather is characterized by high temperatures, with a minimum of 20°C (68°F), an average of 29°C (85°F), and a scorching maximum of 39°C (102°F). This month also sees a significant amount of rainfall at 303 mm (11.9 in) over approximately 14 days, combined with high humidity levels of 91%. In contrast, April presents a much milder climate, with temperatures ranging from a minimum of 5°C (41°F) to a maximum of 29°C (84°F) and an average of 16°C (62°F). The precipitation in April is considerably lower at 135 mm (5.3 in), occurring over 8 days, along with a relative humidity of 78%. For a more detailed look at the weather in this spring month, you can visit Unzen weather in April.
When comparing the weather in August and May, a distinct contrast emerges. August boasts significantly higher temperatures, with averages reaching up to 29°C (85°F) and maximums soaring to 39°C (102°F), while May offers a milder climate, where average temperatures hover around 21°C (69°F) and max out at 30°C (86°F). Humidity levels are notably higher in August at 91%, compared to May's 84%, contributing to a more oppressive feel during the summer month. Additionally, August experiences more rainfall, with 303 mm (11.9 in) over 14 days, compared to May's 214 mm (8.4 in) across 12 days. For a closer look at how these conditions manifest, you can check Unzen weather in May.
In comparing the weather of August and June, August tends to be significantly warmer, with average temperatures reaching 29°C (85°F), whereas June averages a cooler 24°C (75°F). The maximum temperatures in August can peak at an intense 39°C (102°F), while June sees a more moderate maximum of 32°C (90°F). Both months experience considerable rainfall, with August averaging 303 mm (11.9 in) over 14 days and June slightly lower at 262 mm (10.3 in) across 15 days. Additionally, August is more humid, reaching 91% compared to June's 86%. For a detailed look at June weather in Unzen, visit Unzen weather in June.
In comparing the weather between July and August, August tends to be slightly warmer, with average temperatures reaching up to 29°C (85°F), compared to July's average of 27°C (82°F). The maximum temperatures in August can soar to 39°C (102°F), whereas July peaks at 37°C (99°F). However, August experiences more precipitation, totaling 303 mm (11.9 in) over 14 days, while July sees a higher total of 475 mm (18.7 in) over 19 days. Both months share similar humidity levels, with August at 91% and July at 92%. For more detailed insights on July's weather, you can visit Unzen weather in July.
In comparing the weather between August and September, August is characterized by higher temperatures, with a minimum of 20°C (68°F) and an average of 29°C (85°F), reaching a scorching maximum of 39°C (102°F). Notably, it also experiences considerable rainfall, totaling 303 mm (11.9 in) over 14 days, combined with high humidity levels of 91%. In contrast, September brings a drop in temperatures, with a minimum of 16°C (62°F) and an average of 25°C (78°F), peaking at 35°C (94°F). While it still sees significant precipitation, totaling 228 mm (9.0 in) over 15 days, humidity decreases to 84%. For more details on September's weather, visit Unzen weather in September.
In August, the weather tends to be hot and humid, with temperatures ranging from a minimum of 20°C (68°F) to a maximum of 39°C (102°F) and an average of 29°C (85°F). The month also experiences significant rainfall, with 303 mm (11.9 in) of precipitation over 14 days, contributing to a high humidity level of 91%. In contrast, October brings cooler temperatures, with a minimum of 10°C (50°F), an average of 21°C (69°F), and a maximum of 33°C (91°F). The precipitation is notably reduced to 120 mm (4.7 in) across 9 days, and the humidity drops to 83%. For more specifics about October weather, you can check Unzen weather in October.
August and November present a striking contrast in weather patterns. In August, temperatures soar with a minimum of 20°C (68°F) and can reach highs of up to 39°C (102°F), accompanied by significant humidity at 91%. The month is marked by heavy rainfall, totaling 303 mm (11.9 in) over 14 days. In contrast, November brings cooler temperatures, with a minimum of 3°C (38°F) and an average of 15°C (59°F), peaking at a manageable 25°C (78°F). The precipitation is much lighter, averaging 80 mm (3.1 in) across 8 days, and the humidity drops to 81%. For more details on November weather, you can check Unzen weather in November.
August and December present stark contrasts in weather conditions. In August, temperatures soar with a minimum of 20°C (68°F) and an average high reaching 39°C (102°F), accompanied by high humidity at 91%. Rainfall is significant, totaling 303 mm (11.9 in) over 14 days, creating a humid and often sweltering atmosphere. In contrast, December brings much cooler temperatures, with a range from a minimum of 0°C (33°F) to a maximum of 24°C (76°F) and an average of 10°C (49°F). Precipitation decreases to 89 mm (3.5 in) spread over just 7 days, along with a drop in humidity to 79%. For more details on December weather, you can check Unzen weather in December.
August in Unzen is a dynamic month, characterized by warm temperatures and high humidity, creating a sultry atmosphere that stands out from other months. With averages around 29°C (85°F), the heat peaks dramatically at times, notably hitting 39°C (102°F). This month also brings significant rainfall, with precipitation occurring on about half the days, contributing to an overall humidity level of 91%. Visitors can expect a vivid blend of summer warmth with occasional downpours, making August a distinct experience in Unzen's annual weather cycle. For more detailed insights, visit Unzen Climate.