Climate Overview
The climate in Gampaha is hot. The average annual temperature is 27°C and approximately 3000mm of precipitation falls per year. Gampaha receives a notable amount of rainfall throughout the year, including during its driest month. Gampaha sits near the equator, so seasonal temperature differences are minimal throughout the year.
Temperature
Gampaha sees moderate temperature variation throughout the year, ranging from 22°C to 33°C. The warmest month is March, when average highs reach 33°C and the mean temperature sits around 28°C. January is the coolest month, with minimum temperatures around 22°C and an average of 26°C. Daily temperature variation is modest, with an average difference of 7°C between highs and lows.
Precipitation
Gampaha is a very wet location, receiving approximately 3000mm of precipitation annually, which averages out to around 250mm per month. The wettest month is November, averaging 419mm of rainfall. May and October also tend to see above-average precipitation. The driest month is January, with just 64mm. That's 355mm less than November, 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
Gampaha 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 June, averaging 3km/h, though still comfortable for most outdoor activities. The calmest conditions occur in March, with average winds dropping to 1km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 2km/h gap between the calmest and windiest months.
Seasons
93 days until Autumn
It is currently summer in Gampaha, which began on June 21, 2026. Gampaha sits near the equator, so the traditional four-season cycle is less pronounced — temperatures remain relatively stable year-round. The warmest period peaks in March at around 33°C, while the coldest stretch bottoms out in January near 22°C. Autumn is next, beginning on September 23, 2026 — 93 days from now.
Spring
Temperatures range from 24 to 33°C. Rainfall is heavy, totalling around 759mm across the season with a monthly average of 253mm. Winds are generally light, averaging 2km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 24 to 29°C. Rainfall is heavy, totalling around 790mm across the season with a monthly average of 263mm. Winds are generally light, averaging 3km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 23 to 30°C. Rainfall is heavy, totalling around 1072mm across the season with a monthly average of 357mm. Winds are generally light, averaging 2km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 22 to 33°C. Rainfall is heavy, totalling around 378mm across the season with a monthly average of 126mm. 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 Gampaha 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.
