Kumamoto Monthly Rainfall & Precipitation
This page shows both the average monthly rainfall and the number of rainy days in Kumamoto, Kumamoto, Japan. Long-term data from 1990 to 2020 was used to calculate these averages. Now, let's break down all the details for a clearer picture.
Kumamoto is known for its substantial rainfall, with annual precipitation reaching 2037 mm (80 in). While the overall climate is wet, there are notable seasonal patterns that create interesting contrasts, as demonstrated in our graph below.
Monthly Precipitation Levels
The average number of days each month with precipitation (> 0.2 mm (0.01 in))
Kumamoto can be quite wet during June, receiving approximately 436 mm (17 in) of precipitation over 19 rainy days.
In contrast January, experiences much drier conditions, with 85 mm (3.3 in) of rainfall, spread across 18 rainy days.
June, the wettest month, has a maximum daytime temperature of 26°C (79°F). The city receives 131 hours of sunshine in this period. During the driest month January you can expect a temperature of 11°C (52°F). For more detailed insights into the city's temperatures, visit our Kumamoto Temperature page.
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in June
Explore Kumamoto's Historical Precipitation: 1976-2026
Browse day-by-day precipitation records for Kumamoto spanning 51 years. Select any month and year to see actual rainfall and snowfall recorded on each day.
Annual Rainfall in Japan: City Comparison
The map below shows the annual precipitation across Japan. You can also select the different months in case you are interested in a specific month.
heavy rainfall
high
moderate
low
almost none
Kumamoto vs World: Rainfall Compared
Kumamoto's average annual precipitation is 2037 mm (80 in). Let's compare this to some popular worldwide tourist destinations:
New York City, USA, receives 1276 mm (50 in) of rainfall annually, with precipitation evenly distributed throughout the year.
Meanwhile, Buenos Aires, Argentina, enjoys a humid subtropical climate with 1000 mm (39 in) of annual rainfall, mostly in the summer.
Melbourne, Australia, has 690 mm (27 in) of rainfall annually, spread fairly evenly throughout the year.
Kuala Lumpur, Malaysia, receives 2529 mm (100 in) of annual rainfall, characteristic of its equatorial tropical rainforest climate, with consistent rainfall throughout the year and peak months during March and November.
Precipitation amounts are measured using specific gauges installed at weather stations, collecting both rain and snow and any other type of precipitation. Rainfall is measured directly in millimeters, while that from snow and ice is obtained by melting it. Automated systems often incorporate heaters to make this easier.
Information from these stations is transmitted via Wi-Fi, satellite, GPS, or telephone connections to central monitoring networks. This information is immediately updated and integrated into weather models and forecasts.
Precipitation has a very strong role in determining the local climate and ecosystem:
- Changing Rainfall Patterns: Global warming causes drastic changes in the patterns of rainfall. Some areas have been experiencing increased frequency and intensity of rainfall, while other areas experience longer dry spells or even droughts.
- Local Impacts: Many regions are experiencing heavier rainfall in the winter months and drier, hotter summers. This affects agriculture, water resources, and ecosystems.
- Mawsynram in India is noted as being the wettest place on earth, with over 11 meters (36 feet) of rain falling every year.
- In contrast, Antofagasta in Chile is among the driest places on the planet, getting less than 0.1mm (0.004 inches) per year, with some years recording virtually no rainfall.
- Nearly 1,650 thunderstorm cells are estimated over the planet at any given time.
For more detailed information about Kumamoto's weather, including sunshine hours, humidity levels, and temperature data, visit our Kumamoto Climate page.
