Media Center
Climate Bulletin for Sri Lanka (Week of 10 – 17 January 2025)
Highlights
Rainfall Prediction: During the next week, “fairly heavy rainfall” (50-100 mm) is predicted for the Central province, and “moderate rainfall” is
predicted for the Eastern, Uva, Sabaragamuwa, Southern, NorthCentral, North Western, Western and Northern provinces.
Monitored Rainfall: During the last 8 days (1 Jan-8 Jan), SL received an average of 2.4 mm/day of rainfall, while in the hydro catchments, the average rainfall was 3 mm/day. Highest daily rainfall was in Polonnaruwa on 1 Jan (59 mm).
Monitored Sea and Land Temperature: Average land surface temperature was 31.0°C in the last week with warmer anomalies from seasonal average of 1-3°C. Southern plains were warmest followed by Western and Northern plains. Sea surface temperature around Sri Lanka was 1°C above average from 31 Dec – 6 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 (2 Jan – 8 Jan) = 2.4 mm/day Maximum Daily Rainfall: 59.2 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 province driven by the warm SSTs anomalies.
Prediction
Rainfall: During the next week (8 – 14 Jan), “fairly heavy rainfall” (50-100 mm) is predicted for the Central province, and “moderate rainfall” is predicted for the Eastern, Uwa, Sabaragamuwa, Southern, North Central, North Western, Western and Northern provinces.
Temperatures: The temperature will remain normal for the SL during 11 –17 Jan.
Teleconnections: : MJO shall be slightly enhance the rainfall during 7-11 Jan and moderately enhance the rainfall during 12-16 Jan and significantly enhance the rainfall during 17-21 Jan for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the January- February-March, 2025 season shows a 50% or more tendency toward above-normal precipitation for the Southern half of the country, while it shows a 60% 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 |
