Media Center
Climate Bulletin for Sri Lanka (Week of 27 December 2024 – 3 January 2025)
Highlights
Rainfall Prediction: During the next week (24 – 31 Dec), “fairly heavy” rainfall is predicted for the Northern province, and “moderate” rainfall is predicted for the North Central, Eastern, Western, North Western, Sabaragamuwa, Uva, Central and Southern provinces.
Monitored Rainfall: During the last 8 days (19-25 Dec), Sri Lanka received an average of 3 mm/day of rainfall, while in the hydro catchments, the average rainfall was 3.5 mm/day. Highest daily rainfall was in Hambantota on 21 Dec (101 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 Northern and Southern plains. Sea surface temperature around Sri Lanka was 1°C above average from 12 – 18 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: 107.5 mm/day (Menikkanda Tea Factory-Galle)
Average Rainfall in the Met stations for the previous week of (19 – 25 Dec) = 3.0 mm/day
Maximum Daily Rainfall: 101.0 mm & Minimum Daily Rainfall: 0.0 mm.
Wind: North-Westerly 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 Central, North Central and North Western provinces driven by the warm SSTs anomalies.
Prediction
Rainfall: During the next week (24 – 31 Dec), “fairly heavy” rainfall (50-100 mm) is predicted for the Northern province, and “moderate” rainfall (25-50 mm) is predicted for the North Central, Eastern, Western, North Western, Sabaragamuwa, Uva, Central and Southern provinces.
Temperatures: The temperature will remain normal for the SL during 28 Dec 2024 – 3 Jan 2025.
Teleconnections: MJO shall be moderately suppress for the rainfall during 25-29 Dec and slightly suppress for the rainfall during 30 Dec-3 Jan and slightly enhance for the rainfall during 4-8 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 |
