Highlights

Predictions: In the coming weeks, winds shall reverse from northeasterly to westestely due to the southward traverse of the tropical convergence zone over Sri Lanka that is ongoing. From 17 – 23 Mar, the US NOAA Climate Prediction Center predicts that the low rainfall shall continue throughout SL except for the Western Hills and Eastern Plains. During this period, Eastern Plains and Western Hills are predicted to receive rainfall ranging from 15-25 mm. From 18 – 24 Mar, wind speeds are predicted to be 1-3 m/s lower compared to the previous week. Western slopes and Northern Plains are predicted to have temperatures of 34 – 37 °C which is above normal for March.
 
Monitoring: During 11 – 17 Mar, the average daily rainfall was 1.4 mm. The highest daily rainfall was in Katugastota on 13 Mar – 62 mm. During 9 – 15 Mar, winds were from Northeast with 3 – 5 m/s. Overall the temperature was typical for this season across SL. The Southern plains had an average maximum temperature of 33.8°C. The Eastern Hills had an average minimum temperature of 27.5°C.
 

Rainfall Prediction: From 17 – 23 Mar, low rainfall shall continue throughout SL except for the Western Hills and Eastern Plains. During this period, 15-25 mm is predicted for the Eastern Plains and Western Hills; 0-5 mm are predicted for the Northern Plains, Eastern Hills, Western Plains and Southern Plains. From 24-30 Mar, low rainfall is predicted to continue throughout SL, except in the Western Hills and Eastern Plains where 25 – 35 mm rainfall is predicted. (Source: NOAA CPC)

Monitored Rainfall:During 11 – 17 Mar, the average daily rainfall was 1.4 mm. The highest daily rainfall was in Katugastota on 13 Mar, recorded as 62 mm. During this week, there was higher rainfall compared to the previous week across SL.

 
Monitored Land & Sea Temperature: Temperature was seasonable across SL. The Southern plains had the maximum temp of 33.8°C, while the Eastern Hills had the minimum temperature of 27.5°C. The sea surface temperature around Western coasts was above the seasonal average by 0.25°C – 0.5°C, while it was near-neutral around the other coasts.
 
Monitored & Predicted Wind: From 9 – 15 Mar 2026, winds at 1.5 km elevation were mostly from the Northeast at 3 – 5 m/s. From 18 – 24 Mar 2026, winds are predicted to slow ( 1-3 m/s from the East). The wind reversal shall initiate while at 2.8 km level .



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