Hachijojima Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Hachijojima, Japan. Long-term data from 1990 to 2020 was used to calculate these averages. Now, let's explore all the details to give you a full picture.

Hachijojima experiences significant rainfall throughout the year, averaging 2300 mm (91 in) of precipitation annually. However, this abundant rainfall is not evenly distributed, with a distinct rainy season during certain months. You can clearly see this in our monthly precipitation graphs below.

Monthly Precipitation Levels

The average number of days each month with precipitation (> 0.2 mm (0.01 in))

Hachijojima can be quite wet during June, receiving approximately 323 mm (13 in) of precipitation over 19 rainy days.

In contrast August, experiences much drier conditions, with 116 mm (4.6 in) of rainfall, spread across 16 rainy days.

June, the wettest month, has a maximum daytime temperature of 25°C (77°F). The city receives 89 hours of sunshine in this period. During the driest month August you can expect a temperature of 29°C (84°F). For more detailed insights into the city's temperatures, visit our Hachijojima Temperature page.

Hachijojima's average annual precipitation is 2300 mm (91 in). Let's compare this to some popular worldwide tourist destinations:

In Barcelona, Spain, the average annual precipitation is 620 mm (24 in), evenly distributed across the year with no extreme wet or dry seasons.

In Shanghai, China, the annual average precipitation is 1347 mm (53 in), with a humid subtropical climate.

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.

Climate change is affecting precipitation patterns worldwide, including Hachijojima:

• 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.

• "Ginger" was the longest-lasting Atlantic tropical storm, which spun around the open ocean for 28 days in 1971.
• The world's largest snowflake was recorded in the Guinness Book of Records, at 38 cm (15 inches) wide and 20 cm (7.9 inches) thick. The snowflake fell at Fort Keogh, Montana, USA, on 28 January 1887.
• The greatest snowfall recorded was on Mt. Rainier, Washington State, USA, over 31.5 meters (103 feet) fell during the winter of 1972.

For more detailed information about Hachijojima's weather, including sunshine hours, humidity levels, and temperature data, visit our Hachijojima Climate page.