Media Center
Climate Bulletin for Sri Lanka (Week of 3 – 10 January 2025)
Highlights
Rainfall Prediction: During the next week (1 – 7 Jan), “moderate”
rainfall is predicted for the North Central, Eastern, Western, North Western, Sabaragamuwa, Uva, Central and Southern provinces, and “light to moderate” rainfall is predicted for the Northern province.
Monitored Rainfall: During the last 8 days (26 Dec-1 Jan), Sri Lanka received an average of 8 mm/day of rainfall, while in the hydro catchments, the average rainfall was 6 mm/day. Highest daily rainfall was in Polonnaruwa on 31 Dec (91 mm).
Monitored Sea and Land Temperature: Average land surface temperature was 31.0ºC in the last week with warmer anomalies from seasonal average of 1-3 ºC. Eastern plains was warmest followed by Southern and Western plains. Sea surface temperature around Sri Lanka was 1℃ above average from 19 – 25 Dec 2024.
Accumulated Rainfall and Daily Rainfall from 25 Nov 2024
Interpretation
Monitoring
Rainfall: During the last two weeks, there has been Heavy rainfall over the following area: 118.5 mm/day (Deniyaya Tea Estate (AWS)-Matara). Average Rainfall in the Met stations for the previous week of (26 Dec – 1 Jan) = 8.0mm/dayMaximum Daily Rainfall: 90.9 mm & Minimum Daily Rainfall: 0.0 mm
Wind: North-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 somepartsof Northern, Central, North Central, Sabaragamuwa, Western and North Westernprovincesdrivenby the warm SSTs anomalies.
Prediction
Rainfall: During the next week (1 – 7 Jan), “moderate rainfall” (25-50 mm) is predictedfortheNorthCentral, Eastern, Western, North Western, Sabaragamuwa, Uva, Central and Southernprovinces,and “light to moderate rainfall” is predicted for the Northern province.
Temperatures: The temperature will remain normal for the SL during 4 –10 Jan.
Teleconnections: : MJO shall be slightly suppress the rainfall during 1-5 Jan and slightlyenhancetherainfall during 6-10 Jan and moderately enhance the rainfall during 11-15 Jan for Sri Lanka.
Seasonal Precipitation: The precipitation forecast for the January-February-March, 2025seasonshows a 50% or more tendency toward above-normal precipitation for the Southernhalfofthecountry, while it shows a 60% or more tendency toward above-normal precipitationfortheNorthern 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 |
