Climate Overview
The climate in Chilaw is hot. The average annual temperature is 28°C and approximately 1653mm of precipitation falls per year. May is the wettest month, receiving around 279mm of rainfall. Chilaw sits near the equator, so seasonal temperature differences are minimal throughout the year.
Temperature
Chilaw has relatively stable temperatures year-round, staying within a 7°C range. The warmest month is March, when average highs reach 31°C and the mean temperature sits around 29°C. January is the coolest month, with minimum temperatures around 24°C and an average of 27°C. Daily temperature variation is modest, with an average difference of 4°C between highs and lows.
Precipitation
Chilaw is a fairly wet location, receiving approximately 1653mm of precipitation annually, which averages out to around 138mm per month. The wettest month is May, averaging 279mm of rainfall. October and November also tend to see above-average precipitation. The driest month is January, with just 17mm. That's 262mm less than May, 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
Chilaw is relatively calm, with an average annual wind speed of 5km/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 7km/h, though still comfortable for most outdoor activities. The calmest conditions occur in March, with average winds dropping to 3km/h, making it an ideal period for wind-sensitive activities. Wind speeds vary significantly across the year, with a 4km/h difference between the calmest and windiest months. This level of variation is worth factoring into travel plans.
Seasons
92 days until Autumn
It is currently summer in Chilaw, which began on June 21, 2026. Chilaw 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 31°C, while the coldest stretch bottoms out in January near 24°C. Autumn is next, beginning on September 23, 2026 — 92 days from now.
Spring
Temperatures range from 26 to 31°C. Rainfall is heavy, totalling around 447mm across the season with a monthly average of 149mm. Winds are generally light, averaging 4km/h. An umbrella or waterproof jacket is advisable as spring showers are frequent.
Summer
Temperatures range from 26 to 29°C. Rainfall is heavy, totalling around 391mm across the season with a monthly average of 130mm. Winds are generally light, averaging 6km/h. Light, breathable clothing is ideal — perfect conditions for outdoor activities.
Autumn
Temperatures range from 25 to 29°C. Rainfall is heavy, totalling around 666mm across the season with a monthly average of 222mm. Winds are generally light, averaging 4km/h. A waterproof jacket and sturdy footwear are recommended as rain becomes more frequent.
Winter
Temperatures range from 24 to 31°C. Rainfall is relatively light, with around 149mm over the season and a monthly average of 50mm. Winds are generally light, averaging 5km/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 Chilaw 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.
