Media Center
Climate Bulletin for Sri Lanka (Week of 13 – 20 June 2025)
Highlights
Rainfall Prediction: During the next week (11 to 17 June), “heavy” rainfall (100–150 mm) is predicted for the Colombo, Kalutara, Kandy, Gampaha, Ratnapura, Puttalam, and Galle, “fairly heavy” rainfall (50–100 mm) is expected in the Kurunegala, Matale, Nuwara Eliya, Kegalle, Hambantota, and Matara, while “moderate” rainfall (25-50mm) is predicted for the Jaffna, Kilinochchi, Mullaitivu, Mannar, Vavuniya, Anuradhapura, Plonnaruwa, Trincomalee, Batticaloa, Ampara, Moneragala, and Badulla districts.
Monitored Rainfall: During the last 8 days (04 – 11 June), Sri Lanka received an average rainfall of 3.1 mm per day. Most days over the month of May had above-average rainfall levels. Notably, 17th May recorded the highest daily average rainfall of 19 mm/day.
Monitored and Predicted Wind: From May 03 to 09 June, winds at 1.5 km were mostly from the North-West at speeds ranging between 8-15 m/s. From 12 to 18 June, winds are predicted to come from the West, speed ranging between 10-30 m/s.
Monitored Sea and Land Temperature: Average maximum land surface temperature was 31.8 °C in the last week. The Eastern plains were the warmest, followed by the Western and Central plains. The sea surface temperature around Sri Lanka ranged from near-neutral in southern part, to 1.5°C above average in the eastern part from 03 to 09 June, 2025.
Interpretation
Monitoring
Rainfall: Average Rainfall in the Airport Stations for the previous week of (04 – 11 June) = 3.1 mm/day. Maximum Daily Rainfall: 48.3 mm & Minimum Daily Rainfall: 0.0 mm.
Wind: Westerly and North-Westerly winds prevailed over the sea area and around the island last week, with wind speeds ranging between 8-15 m/s from 03-09 June.
Temperatures: Temperature anomalies were moderately warm in the Western, Sabaragamuwa and Central Provinces, while near-neutral in other parts of Sri Lanka from June 1 to 7.
Prediction
Rainfall: During the next week (11 to 17 June), “heavy” rainfall (100–150 mm) is predicted for the Colombo, Kalutara, Kandy, Gampaha, Ratnapura, Puttalam, and Galle, “fairly heavy” rainfall (50–100 mm) is expected in the Kurunegala, Matale, Nuwara Eliya, Kegalle, Hambantota, and Matara, while “moderate” rainfall (25-50mm) is predicted for the Jaffna, Kilinochchi, Mullaitivu, Mannar, Vavuniya, Anuradhapura, Plonnaruwa, Trincomalee, Batticaloa, Ampara, Moneragala, and Badulla districts.
Temperatures: The maximum temperature will remain above normal in some parts of the Northern and Eastern provinces, with maximum temperatures reaching between 35°C and 40°C of Sri Lanka from 12 to 18 June.
Teleconnections: The MJO will moderately suppress from 10 to 14 June, slightly suppress rainfall from 15 to 24 June.
Seasonal Precipitation: The precipitation forecast for the June-July-August 2025 season shows a 40% or more tendency toward above normal precipitation of Sri Lanka.
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 |
