Media Center
Climate Bulletin for Sri Lanka (Week of 18- 25 April 2025)
Highlights
Rainfall Prediction: During the next week (April 16–22), “fairly heavy” rainfall (50–100 mm) is predicted for the Western Province, while “moderate” rainfall (25–50 mm) is expected in the Sabaragamuwa, Uva, Central, and North-Western Provinces. “Light to moderate” rainfall is expected in the Southern, Eastern, and North-Central Provinces, while “light showers” are expected in the Northern Province.
Monitored Rainfall: During the last 8 days (09 – 16 April), Sri Lanka received an average rainfall of 5.1 mm per day, while the hydro catchment areas recorded an average of 6.2 mm per day. Highest daily rainfall was in Mattala on 10th April (62.3mm).
Monitored and Predicted Wind: From 08- 14 Apr, winds at 850mb (1.5 km) from the Southwest reached to 6m/s. From April 17 to April 23, winds are predicted to come from the south-west, with wind speeds ranging between 4 – 5m/s.
Monitored Sea and Land Temperature: Average maximum land surface temperature was 32.1°C in the last week. The Northern plains were the warmest, followed by the Eastern and Southern plains. The sea surface temperature around Sri Lanka ranged between 0.5°C and 0.25°C from 08 April to 14 April 2025.
Interpretation
Monitoring
Rainfall: Average Rainfall in the Met Stations for the previous week of (09 Apr – 16 Apr) = 5.1 mm/day. Maximum Daily Rainfall: 62.3 mm & Minimum Daily Rainfall: 0.0 mm.
Wind: Southwesterly winds prevailed over the sea area and around the island last week, with wind speeds ranging between 5–8 m/s.
Temperatures: Temperature anomalies were near neutral for Sri Lanka from April 06 to April 12.
Prediction
Rainfall: During the next week (April 9–15), “fairly heavy” rainfall (50–100 mm) is predicted for the Western Province, while “moderate” rainfall (25–50 mm) is expected in the Sabaragamuwa, Uva, Central, and North-Western Provinces. “Light to moderate” rainfall is expected in the Southern, Eastern, and North-Central Provinces, while “light showers” are expected in the Northern Province.
Temperatures: The temperature will remain above normal in some parts of the Northern, North-Central, and Eastern Provinces from April 17 to April 26, with maximum temperatures reaching up to 37°C. It will remain normal in other parts of Sri Lanka during this period.
Teleconnections: The MJO will be slightly suppress the rainfall during from April 15 to April 30.
Seasonal Precipitation: The precipitation forecast for the May–June–July 2025 season shows more tendency toward above-normal precipitation on the western side of the country, while the rest of the country is expected to receive normal precipitation.
Terminology for Rainfall Ranges
| Terminology | Rainfall (mm/week) |
| Light Showers | Less than 12.5 mm |
| Light to Moderate | Between 12.5 mm and 25 mm |
| Moderate | Between 25 mm and 50 mm |
| Fairly Heavy | Between 50 mm and 100 mm |
| Heavy | Between 100 mm and 150 mm |
| Very Heavy | More than 150 mm |
