Media Center
Climate Bulletin for Sri Lanka (Week of 17 – 24 January 2025)
Highlights
Rainfall Prediction: During the next week, “fairly heavy rainfall” (50-100 mm) is predicted for the Eastern and North- Central province, and “moderate rainfall” is predicted for the Uva, Sabaragamuwa, Southern, Northern and North Western provinces and “Light showers” shows some parts of western province.
Monitored Rainfall: During the last 8 days (1 Jan-8 Jan), SL received an average of 10.7 mm/day of rainfall, while in the hydro catchments, the average rainfall was 7.7 mm/day. Highest daily rainfall was in Mannar on 14 Jan (90.5 mm).
Monitored Sea and Land Temperature: Average land surface temperature was 28.0°C in the last week with warmer anomalies from seasonal average of 1-3°C. The western plains were the warmest, followed by the northern and southern plains. Sea surface temperature around Sri Lanka was 0.5°C above average from 7 Jan – 13 Jan 2025
Accumulated Rainfall and Daily Rainfall from 25 Nov 2024

Interpretation
Monitoring
Rainfall: Average Rainfall in the Met Stations for the previous week of (9 Jan – 15 Jan) = 10.7 mm/day. Maximum Daily Rainfall: 90.5 mm & Minimum Daily Rainfall: 0.0 mm.
Wind: Easterly winds prevailed in the sea area and around the island last week.
Temperatures: The temperature anomalies were near-neutral for Sri Lanka except for some parts of Sabaragamuwa, Western and Central provinces driven by the warm SSTs anomalies.
Prediction
Rainfall: During the next week (15 – 21 Jan), “fairly heavy rainfall” (50–100 mm) is predicted for the Eastern and North-Central provinces. “Moderate rainfall” is expected in the Uva, Sabaragamuwa, Southern, North-Western, Central, and Northern provinces, while “light to moderate rainfall” is predicted for the Western province
Temperatures: The temperature will remain normal for the SL during 17 –25 Jan.
Teleconnections: MJO will slightly enhance the rainfall during 14-18 January, Significantly enhance the rainfall during 19-28 January.
Seasonal Precipitation: The precipitation forecast for the February-March-April, 2025 season shows a 45% or more tendency toward above-normal precipitation for the Southern half of the country, while it shows a 50% or more tendency toward above-normal precipitation for the Northern half of the country.
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 |