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Surabaya Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Surabaya, East Java, Indonesia. The figures are based on a 30-year period (1990–2020) to provide a reliable average. Let's explore the details to provide you with a complete overview.

Surabaya experiences significant rainfall throughout the year, averaging 1805 mm (71 in) of precipitation annually. However, this abundant rainfall is not evenly distributed, with a distinct dry and 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))

The seasons in Surabaya, bring significant changes in precipitation. The wettest month, February, receives heavy rainfall, with an average of 304 mm (12 in) of precipitation. This rainfall is distributed across 17 rainy days.

In contrast, the driest month, August, experiences much less rainfall, totaling 8.8 mm (0.3 in) over a single rainy day. These distinct seasonal differences provide diverse experiences throughout the year.

February, the wettest month, has a maximum daytime temperature of 32°C (90°F). The city receives 124 hours of sunshine in this period. During the driest month August you can expect a temperature of 33°C (91°F). For more detailed insights into the city's temperatures, visit our Surabaya Temperature page.

Daily Historical Precipitation

48-year average (1976-2025)

Average daily rainfall for each day of the month based on long-term records.

Average precipitation in June

Explore Surabaya's Historical Precipitation: 1976-2026

Browse day-by-day precipitation records for Surabaya spanning 51 years. Select any month and year to see actual rainfall and snowfall recorded on each day.

Annual Rainfall in Indonesia: City Comparison

The map below shows the annual precipitation across Indonesia. You can also select the different months in case you are interested in a specific month.

Annual
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Legend heavy rainfall high moderate low almost none
Heavy annual rainfall has been defined as more than 1000 mm (39 in) precipitation. High: 600 mm (24 in) to 1000 mm (39 in). Moderate: 250 mm (9.8 in) to 600 mm (24 in). Low: less than 250 mm (9.8 in).

Surabaya vs World: Rainfall Compared

Surabaya's average annual precipitation is 1805 mm (71 in). Let's compare this to some popular worldwide tourist destinations:

The city of Rome, Italy, has an average annual precipitation of 832 mm (33 in), spread fairly evenly throughout the year.

Meanwhile, Buenos Aires, Argentina, enjoys a humid subtropical climate with 1000 mm (39 in) of annual rainfall, mostly in the summer.

Perth, Australia, receives 565 mm (22 in) of rainfall annually, mostly during the winter months.

Singapore, situated near the equator, gets 2581 mm (102 in) of rainfall annually, with no distinct dry season and consistent monthly precipitation.

How is Precipitation Measured?

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.

  • Rainy Seasons: Many parts of the world have well-defined wet seasons where precipitation is distinctly higher. These are normally accompanied by lush vegetation and temperature patterns.
  • Dry Seasons: In areas where the climate is either desert or Mediterranean, the amount of precipitation is drastically reduced, leading to a shortage of water and arid conditions.
  • Interesting weather facts

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


    Current rainfall in Surabaya

    More climate data for Surabaya