Highlights

Monitoring

Sri Lanka experienced a relatively dry period from 5-17 Aug with daily average rainfall ranging from 1-5 mm. During 12-18 Aug, the average daily rainfall across SL was 1.6 mm. The highest daily rainfall was in Mullaitivu – 27 mm on 12 Aug, Badulla – 22 mm & Pottuvil – 17 mm on 14 Aug. August has the highest winds in SL generally, marking the beginning of the kite flying season.

From 10-16 Aug 2026, winds at 1.5 km elevation were mostly from the Northwest at  8-10 m/s. Overall the temperature was typical for August across SL. The Eastern Plains had an average maximum temperature of 35.4°C.  The Eastern Hills had an average minimum temperature of 18.8°C.

Predictions

From 18-24 Aug, the US NOAA Climate Prediction Center predicts that the overall rainfall across SL shall decrease compared to the previous week. During this period; Eastern Plains are predicted to receive rainfall of 35-55 mm; Western & Eastern Hills are predicted to receive 15-35 mm; Northern, Eastern and Western Plains are predicted to receive 0-5 mm. From 19-25 Aug, wind speeds are predicted to be 4-10 m/s from the Northwest & Southwest.

El Niño Event

El Niño conditions continue to prevail across the equatorial Pacific Ocean (Niño 3.4 region). Currently, sea surface temperature in the Niño 3.4 region are around 2.1°C above average. Meanwhile, the Indian Ocean could be gradually transitioning towards a positive IOD phase, which is typically associated with El Niño. According to CCSR/IRI Multi-Model Probability Forecast, there is a 45% likelihood of Sri Lanka receiving higher-than-normal rainfall during August-October, increasing 60% during September-November.

Rainfall Prediction

From 18–24 Aug, 35–55 mm is predicted for the Eastern Plains; 15–35 mm is predicted for the Western & Eastern Hills; 0–5 mm is predicted for the Northern, Western & Eastern Plains. From 25–31 Aug, rainfall shall be similar to the previous week: 35–55 mm is predicted for the Eastern Plains; 5–35 mm is predicted for the rest of Sri Lanka.

(Source: NOAA CPC)

Monitored Rainfall

Sri Lanka experienced a relatively dry period from 5–17 Aug, with daily average rainfall ranging from 1–5 mm. During 12–17 Aug, the average daily rainfall across Sri Lanka was 1.6 mm. Highest daily rainfall was recorded in Mullaitivu – 27 mm on 12 Aug, Badulla – 22 mm, and Pottuvil – 17 mm on 14 Aug.

Monitored Land & Sea Temperature

During 12–17 Aug, average maximum temperature in Sri Lanka was 32.4°C, higher than the previous week (31.7°C). The Eastern Plains was the warmest, at 35.4°C. The sea surface temperature around SL was warmer by 0.5°C around the southern coasts and near-neutral around the rest of the coasts.

Monitored & Predicted Wind

August generally has the highest winds in SL, marking the beginning of the kite-flying season. From 10–16 Aug 2026, winds at 1.5 km elevation were mostly from the Northwest, at speeds of 8–10 m/s. From 19–25 Aug 2026, winds are predicted to slow down to 4–10 m/s and arrive from the Northwest & Southwest.