San José Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in San José, San José Province, Costa Rica. Long-term data from 1990 to 2020 was used to calculate these averages. Let's explore the details to provide you with a complete overview.

San José experiences significant rainfall throughout the year, averaging 3381 mm (133 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))

Significant seasonal changes in precipitation occur throughout the year. During the wettest month, October receives substantial rainfall, averaging 490 mm (19 in) of precipitation, recorded across 23 rainy days.

In contrast, the driest month, March brings less rainfall, with 61 mm (2.4 in) over 8 rainy days.

October, the wettest month, has a maximum daytime temperature of 24°C (75°F). The city receives 162 hours of sunshine in this period. During the driest month March you can expect a temperature of 25°C (77°F). For more detailed insights into the city's temperatures, visit our San José Temperature page.

San José's average annual precipitation is 3381 mm (133 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.

Beijing, China, receives 560 mm (22 in) of annual precipitation, concentrated in the summer months.

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.

The proximity of a location to a large body of water can significantly affect its rainfall patterns:

• Ocean Influence: Coastal regions typically receive more rainfall due to the presence of moisture-laden winds from the ocean. These regions tend to have more humid climates and experience more frequent precipitation, especially in winter.
• Continental Climates: Areas further from the sea, such as inland or continental regions, experience less frequent rainfall and more extreme seasonal variations in precipitation.

• "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 San José's weather, including sunshine hours, humidity levels, and temperature data, visit our San José Climate page.