The climate of Kumamoto
Tucked away in the southern segment of
Japan,
Kumamoto is a city that experiences a Humid subtropical type of climate, known within the Köppen climate classification as Cfa. With no specific dry season, this climate classification sets the tone for Kumamoto's annual weather rhythm, providing a sense of predictability that is subject to mild alterations and variations.
A review of the climate data divulges a consistent pattern throughout the year. Temperature reaches the highest levels, peaking at 30.4°C (86.7°F) in
August, and dropping to its lowest in
January, with minimum temperatures recorded at 1.7°C (35.1°F). There is a smooth transition between these extremes, with the temperature gradually increasing in spring and early summer, and gradually declining in late autumn and winter.
Humidity too, mirrors a similar pattern. The average relative humidity hovers around 74-75% in colder months (from
November to
February), rises through the summer (reaching 83% in
July), and then starts to decline in
September.
Rainfall here follows a beautiful ebb and flow. The heaviest rainfall occurs in the monsoon months of
June and July, with measures hitting the 200mm (7.87") mark, accompanied by rainfall days soaring up to 23. Precipitation decreases sharply to 105mm (4.13") in August and continues this downward trend until it hits its lowest mark in
December, at 36mm (1.42").
The best time to visit Kumamoto
Given the trends in weather parameters, the period from
April to
June emerges as the most favorable time to visit
Kumamoto. During these months, the average high temperature ranges from 18.3°C (64.9°F) in April to 25.2°C (77.4°F) in June, ensuring comfortable conditions for visitor activities. Relative humidity is on the lower side, fluctuating between 72 to 73%. Rainfall does start to creep up in
May, but the average does not exceed 78mm (3.07"), and with daylight hours increasing from 13 to 14.3, travelers have ample opportunity to explore.
The worst time to visit Kumamoto
The least inviting months to visit
Kumamoto are
July and
August. The hot and humid conditions, with temperatures rising to 30.4°C (86.7°F) and relative humidity scaling up to 83%, can be challenging. Moreover, the heavy rainfall during July of precipitation. Months with snowfall are
January through
March and
December. January is the month with the most snowfall in Kumamoto. Snow falls for 3.3 days and accumulates 16mm (0.63") of snow. In January, the average sea temperature is 19°C (66.2°F).
Note: Most people find swimming in 19°C (66.2°F) to be not enjoyable. The control of one's breathing becomes more challenging as the water temperature drops below 21°C (69.8°F). In Kumamoto, the average length of the day in January is 10h and 16min.
On the first day of January in Kumamoto,
Japan, sunrise is at 07:19 and sunset at 17:21. On the last day of the month, sunrise is at 07:13 and sunset at 17:47 JST. January has the least sunshine of the year, with an average of 5.1h of sunshine. The months with the lowest UV index are January and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for the average person.
Note: The maximum UV index of 2 during January leads to these instructions:
Many can withstand an hour in the sun without burning, yet children must always have protection against sunlight. During midday, the Sun's radiation is strongest, and it's advisable to reduce direct exposure. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades. Be mindful! The reflection from snow can increase the Sun's UV radiation nearly twice.
Weather in February
The trend from cold to colder mildly fades away as
February sees temperatures rising slightly in
Kumamoto city. The highest ascent is recorded at 10.3°C (50.5°F) and the lowest descent hits at 3.1°C (37.6°F). Despite the increased temperature levels, umbrellas remain as needful as overcoats because February is rainier than
January.
Weather in February »Weather in March
In
March, the
Kumamoto's weather conditions reveal spring's steady arrival, evident in a temperature hike up to 13.5°C (56.3°F) and a dive down to 5.6°C (42.1°F). Seasonal changes continue as the city sheds its winter coat and embraces warmer afternoons.
Weather in March »
Weather in April
April in
Kumamoto City observes an evident increase in thermal readings, ranging from a swell to 18.3°C (64.9°F) and a dip to 9.8°C (49.6°F), signifying the impending full bloom of spring. The city boasts comfortable balmy days and mildly nippy evenings.
Weather in April » Weather in May
May in
Kumamoto experiences a considerable jump in temperature reaching a high of 23.2°C (73.8°F) and going down to 14.3°C (57.7°F). With summer knocking at the doorstep, the city feels the warmth in the air. More hours under the sun add to the prevailing warmth and while rain does arrive, it's minimal and fails to bring much cooling.
Weather in May » Weather in June
June in
Kumamoto City ushers in summer, with temperatures hovering between a high of 25.2°C (77.4°F) and a low of 18.5°C (65.3°F). Coupled with these soaring temperatures, June sees a significant jump in rainfall. The city witnesses a climatic shift towards a 'hot and humid' character, aided by lengthy days under the sun.
Weather in June »
Weather in July
In
July,
Kumamoto reaches its heated peak, as the summer temperature wavers between a maximum of 28.4°C (83.1°F) and a minimum of 22.3°C (72.1°F). As summer takes center stage, the city undergoes its warmest phase. Bright sunlight coupled with high humidity creates a distinct hot and muggy atmosphere.
Weather in July »Weather in August
August in
Kumamoto city swelters under an intense summer heat with temperatures swinging from a high of 30.4°C (86.7°F) to a low of 23.3°C (73.9°F). The smouldering summer days dominate, making this month one of the hottest in the year.
Weather in August » Weather in September
As
Kumamoto transitions into the fall,
September records temperatures ranging from a maximum of 26.9°C (80.4°F) to a minimum of 19.6°C (67.3°F). With days gradually shortening, there is less daylight available, yet humidity levels remain moderately high.
Weather in September »
Weather in October
October in
Kumamoto ushers autumn into the fore with temperatures ranging from 22.5°C (72.5°F) to 15.1°C (59.2°F). The city sees a considerable reduction in warmth, making this an ideal time for outdoor sightseeing. The atmosphere remains comfortably dry with a decrease in the relative humidity level.
Weather in October » Weather in November
November in
Kumamoto sees a sharp knockdown in temperature with figures swiveling between a high of 16.5°C (61.7°F) and a low of 9.9°C (49.8°F). The cool weather is an indicator of the impending winter season. The city enjoys mild and sunny days while the nights begin to see a crisp coolness.
Weather in November » Weather in December
As the year winds down,
December brings winter to
Kumamoto with a substantial dip in temperature, as the city alternates between a high of 10.4°C (50.7°F) and a low of 4.4°C (39.9°F). Along with a substantial drop in sea temperature, the colder weather is quite observable.
Weather in December »