Climate Overview
The climate in Surabaya is hot. The average annual temperature is 29°C and approximately 1817mm of precipitation falls per year. February is the wettest month, receiving around 294mm of rainfall. Surabaya sits near the equator, so seasonal temperature differences are minimal throughout the year.
Temperature
Surabaya has relatively stable temperatures year-round, staying within a 8°C range. The warmest month is October, when average highs reach 33°C and the mean temperature sits around 29°C. July is the coolest month, with minimum temperatures around 25°C and an average of 28°C. Daily temperature variation is modest, with an average difference of 6°C between highs and lows.
Precipitation
Surabaya is a fairly wet location, receiving approximately 1817mm of precipitation annually, which averages out to around 151mm per month. The wettest month is February, averaging 294mm of rainfall. March and December also tend to see above-average precipitation. The driest month is August, with just 10mm. That's 284mm less than February, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic.
Wind
Surabaya is relatively calm, with an average annual wind speed of 12km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is September, averaging 14km/h, though still comfortable for most outdoor activities. The calmest conditions occur in April, with average winds dropping to 9km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 5km/h gap between the calmest and windiest months.
Seasons
90 days until Winter
It is currently autumn in Surabaya, which began on March 20, 2026. Surabaya sits near the equator, so the traditional four-season cycle is less pronounced — temperatures remain relatively stable year-round. The warmest period peaks in October at around 33°C, while the coldest stretch bottoms out in July near 25°C. Winter is next, beginning on June 21, 2026 — 90 days from now.
Spring
Temperatures range from 26 to 33°C. Rainfall is heavy, totalling around 341mm across the season with a monthly average of 114mm. Winds are generally light, averaging 12km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 26 to 32°C. Rainfall is heavy, totalling around 831mm across the season with a monthly average of 277mm. Winds are generally light, averaging 13km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 26 to 32°C. Rainfall is heavy, totalling around 560mm across the season with a monthly average of 187mm. Winds are generally light, averaging 10km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 25 to 32°C. Rainfall is relatively light, with around 85mm over the season and a monthly average of 28mm. Winds are generally light, averaging 12km/h. A light jacket or sweater is usually sufficient, though cooler evenings may call for an extra layer.
Monthly Climate Data
The table below shows monthly climate averages for Surabaya based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.
