Climate Overview
The climate in Dumai is hot. The average annual temperature is 28°C and approximately 2607mm of precipitation falls per year. Dumai receives a notable amount of rainfall throughout the year, including during its driest month. Dumai sits near the equator, so seasonal temperature differences are minimal throughout the year.
Temperature
Dumai has relatively stable temperatures year-round, staying within a 7°C range. The warmest month is April, when average highs reach 32°C and the mean temperature sits around 28°C. September is the coolest month, with minimum temperatures around 25°C and an average of 27°C. Daily temperature variation is modest, with an average difference of 6°C between highs and lows.
Precipitation
Dumai is a very wet location, receiving approximately 2607mm of precipitation annually, which averages out to around 217mm per month. The wettest month is November, averaging 393mm of rainfall. December and October also tend to see above-average precipitation. The driest month is August, with just 129mm. That's 264mm less than November, the wettest month. Precipitation varies noticeably between seasons, with the second half (July to December) of the year generally seeing more rainfall.
Wind
Dumai is relatively calm, with an average annual wind speed of 2km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is February, averaging 2km/h, though still comfortable for most outdoor activities. The calmest conditions occur in May, with average winds dropping to 2km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 0km/h between the calmest and windiest months.
Seasons
93 days until Autumn
It is currently summer in Dumai, which began on June 21, 2026. Dumai sits near the equator, so the traditional four-season cycle is less pronounced — temperatures remain relatively stable year-round. The warmest period peaks in April at around 32°C, while the coldest stretch bottoms out in September near 25°C. Autumn is next, beginning on September 23, 2026 — 93 days from now.
Spring
Temperatures range from 25 to 32°C. Rainfall is heavy, totalling around 671mm across the season with a monthly average of 224mm. Winds are generally light, averaging 2km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 25 to 32°C. Rainfall is heavy, totalling around 409mm across the season with a monthly average of 136mm. Winds are generally light, averaging 2km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 25 to 31°C. Rainfall is heavy, totalling around 909mm across the season with a monthly average of 303mm. Winds are generally light, averaging 2km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 25 to 31°C. Rainfall is heavy, totalling around 618mm across the season with a monthly average of 206mm. Winds are generally light, averaging 2km/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 Dumai 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.
