Media Center
Climate Bulletin for Sri Lanka (Week of 24 – 31 January 2025)
Highlights
Rainfall Prediction: During the next week, “fairly heavy rainfall” (50–100 mm) is predicted for the Southern province. “Moderate rainfall” is expected in the Uva, Eastern, Sabaragamuwa, Central, and Northern Central provinces, while “light showers” is predicted for the Western, North Western and Northern provinces.
Monitored Rainfall: During the last 8 days (15 Jan-22 Jan), SL received an average of 12.2 mm/day of rainfall, while in the hydro catchments, the average rainfall was 12.6 mm/day. Highest daily rainfall was in Anuradhapura on 18 Jan (73.5 mm).
Monitored Sea and Land Temperature: Average maximum land surface temperature was 28.0ºC in the last week with warmer anomalies from seasonal average of 1 ºC. The western plains were the warmest, followed by the Southern and Northern plains. Sea surface temperature around Sri Lanka was 0.5 ℃above average from 14 Jan – 20 Jan 2025.

Interpretation
Monitoring
Rainfall: In the 2nd week and 3rd week of January(15-21Jan),most days received significantly above
average rainfall levels.Notably, 18th f January received significantly above-average rainfall
level that reached up to 40mm/day. In the first week of January,majority of days received
significantly below-average rainfall levels.
Wind: Easterly winds prevailed in the sea area and around the island last week.
Temperatures: The temperature anomalies were near-neutral for Sri Lanka.
Prediction
Rainfall: During the next week (22 – 28 Jan), “fairly heavy rainfall” (50–100 mm) is predicted for the Southern province. “Moderate rainfall” is expected in the Uva, Eastern, Sabaragamuwa, Central, and Northern-Central provinces, while “light showers” is predicted for the Western, North-Western and Northern provinces.
Temperatures: The temperature will remain normal for the SL during 23 January – 02 February.
Teleconnections: MJO will significantly enhance the rainfall during 21-25 January, moderately enhance the rainfall during 26-30 January and slightly suppressed the rainfall during 31 January-4 February.
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 |