Highlights

Predictions: From 28 Apr – 1 May, the US NOAA Climate Prediction Center predicts that the rainfall shall increase across SL. During this period, Western Hills & Plains are predicted to receive rainfall ranging from 65-85 mm. From 29 Apr – 5 May, wind speeds are predicted to be 2-6 m/s.
 
 
Monitoring: Sri Lanka has reached the end of its dry season. During 22 – 28 Apr, the average daily rainfall was 4 mm. The highest daily rainfall was in Kurunegala – 61 mm on 22 Apr, Katunayaka – 50 mm on 26 Apr and Vavuniya – 45 mm on 28 Apr. During 20 – 26 Apr, winds were from Southeast with 1–3 m/s. Overall the temperature was typical for April across SL. The Southern plains had an average maximum temperature of 33.4°C. The Eastern Hills had an average minimum temperature of 19.0°C.
 

Rainfall Prediction: From 28 Apr – 1 May, rainfall is predicted to increase throughout SL: 65-85 mm is predicted for the Western Hills Plains; 35-65 mm is predicted for the Southern Plains, Eastern Hills & Plains; 15-35 mm is predicted for the Northern Plains. From 5 – 11 May, rainfall shall continue to increase: 65-95 mm is predicted for the Western Hills & Plains; 45-65 Southern Plains, Eastern Hills & Plains; 25-45 mm is predicted for the rest of SL. (Source: NOAA CPC)

Monitored Rainfall: Sri Lanka has reached the end of its dry season. During 22 – 28 Apr, the average daily rainfall was 4 mm. The highest daily rainfall was in Kurunegala – 61 mm on 22 Apr, Katunayaka – 50 mm on 26 Apr and Vavuniya – 45 mm on 28 Apr.

 

Monitored Land & Sea Temperature: During 22 – 28 Apr, maximum average temp in SL was 32.9°C, lower compared to the previous week – 33.4°C. Eastern Hills had the lowest temperatures – 28.1°C. The sea surface temperature around SL was above the seasonal average by 1°C – 1.5°C.
 

Monitored & Predicted Wind: Typical wind reversal in April is ongoing from (South-)East to (South-)West. From 20 – 26 Apr 2026, winds at 1.5 km elevation were mostly from the Southeast at 1 – 3 m/s. From 29 Apr – 5 May 2026, winds are predicted to speed ( 2-6/s from the Southwest).



Terminology for Rainfall Ranges

TerminologyRainfall (mm/week)
Light ShowersLess than 12.5 mm
Light to ModerateBetween 12.5 mm and 25 mm
ModerateBetween 25 mm and 50 mm
Fairly HeavyBetween 50 mm and 100 mm
HeavyBetween 100 mm and 150 mm
Very HeavyMore than 150 mm