San Antonio Monthly Rainfall & Precipitation
This page shows both the average monthly rainfall and the number of rainy days in San Antonio, Heredia, Costa Rica. These values are calculated using 30 years of data (1990–2020) to ensure accuracy. Now, let's break down all the details for a clearer picture.
San Antonio has a relatively rainy climate with high precipitation levels, averaging 3059 mm (120 in) of rainfall annually. Despite the high annual total, it does experience a distinct rainy season during certain months. Examine our detailed charts below to understand these seasonal patterns.
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 467 mm (18 in) of precipitation, recorded across 23 rainy days.
In contrast, the driest month, March brings less rainfall, with 43 mm (1.7 in) over 8 rainy days.
October, the wettest month, has a maximum daytime temperature of 25°C (77°F). The city receives 162 hours of sunshine in this period. During the driest month March you can expect a temperature of 27°C (81°F). For more detailed insights into the city's temperatures, visit our San Antonio Temperature page.
Annual Rainfall in Costa Rica: City Comparison
The map below shows the annual precipitation across Costa Rica. You can also select the different months in case you are interested in a specific month.
heavy rainfall
high
moderate
low
almost none
San Antonio vs World: Rainfall Compared
San Antonio's average annual precipitation is 3059 mm (120 in). Let's compare this to some popular worldwide tourist destinations:
In Lisbon, Portugal, the average annual precipitation is 774 mm (30 in), characterized by wet winters and dry summers typical of the Mediterranean climate.
In Seoul, South Korea, the average annual precipitation is 1237 mm (49 in), with most rain falling during the summer monsoon season.
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 San Antonio:
- 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 San Antonio's weather, including sunshine hours, humidity levels, and temperature data, visit our San Antonio Climate page.
