Sri Lanka is experiencing a complex and dynamic weather pattern, marked by fluctuating temperatures, widespread thundershowers, and frequent severe lightning advisories. The nation is also preparing for the anticipated impact of El Niño, which is expected to significantly reduce rainfall during the upcoming Southwest Monsoon.
Persistent Heat and Health Precautions
The Department of Meteorology's Natural Disaster Early Warning Centre has consistently issued warm weather advisories. A ‘Caution Level’ Heat Index was in effect for up to 21 districts between April 6 and April 17, followed by an 'attention required' level warning on April 19 across several provinces including Northern, North-Central, North-Western, Western, Sabaragamuwa, Eastern, and Southern, along with Monaragala district. Director General Athula Karunanayake indicated that hot weather conditions were expected to persist until the end of May.
Recent observations on May 3 recorded the highest maximum temperature at 36.3°C in Pottuvil, with other areas like Monaragala (35.7°C), Mullaitivu (35.1°C), and Mattala (34.8°C) also experiencing high temperatures. The public is strongly urged to take action to minimize potential health impacts, with particular caution advised for small children, elderly individuals, and those with existing illnesses. Residents are advised to be vigilant, rest in shaded areas, drink sufficient water, wear white or light-colored clothing, and limit strenuous activities to prevent fatigue and heat cramps.
Widespread Rainfall and Thundershower Forecasts
A significant shift towards wetter weather began on April 2, following a maximum temperature of 37°C in Kurunegala and 39mm of rainfall in Kegalle on April 1. Showers or thundershowers were consistently anticipated from April 6 to April 12, primarily in the evening after 1:00 PM or 2:00 PM. Moderate to heavy rainfall, potentially exceeding 50 mm, was likely in the Western, Central, and Sabaragamuwa provinces, and the Kurunegala and Polonnaruwa districts, with some areas experiencing fairly heavy rainfall exceeding 75 mm. Notably, heavy thundershowers on April 12 in the water catchment areas on the western slopes of the Central hills (Castlereagh, Maussakelle, and Upper Kotmale) ended a nearly three-month dry spell that had impacted reservoir levels and drinking water supplies.
Subsequent forecasts and observations included:
* April 13-17: Widespread showers, with Medawachchiya receiving 136.5 mm on April 14.
* April 20-21: Favorable atmospheric conditions for evening thundershowers, with fairly heavy rainfall between 75 mm and 100 mm forecast for Central, Sabaragamuwa, Western, North-Central, and Southern provinces on April 20, and heavy rainfall exceeding 100 mm anticipated on April 21 in Western, Sabaragamuwa, Central, North Western provinces, and Galle, Matara, and Anuradhapura districts.
* April 22-24: Moderately heavy rains exceeding 75 mm were forecast for various provinces and districts.
* April 25 - May 2: Consistent forecasts for showers or thundershowers, mostly in the afternoon, with morning rain in coastal and southern areas. Fairly heavy rainfall exceeding 75mm was highly probable in Western, Sabaragamuwa, Central, Southern, Uva, North Central provinces, and Kurunegala district on April 27, and similar conditions on April 28.
* May 3: Showers or thundershowers were forecast for many parts of the island, with fairly heavy falls above 50 mm anticipated in Sabaragamuwa province and in Colombo, Kalutara, Galle, and Matara districts.
* May 4: Showers or thundershowers were expected after 2:00 PM in several provinces and districts, with fairly heavy rainfall exceeding 50 mm likely in parts of the Western and Sabaragamuwa provinces, and in the Galle and Matara districts. Morning showers were anticipated in coastal areas of the Western Province and in the Galle and Matara districts, with additional mentions of Kalutara, Colombo, and Puttalam districts.
* May 7: Prevailing showery conditions were expected to continue due to a low-level atmospheric disturbance, with fairly heavy falls exceeding 75 mm in some areas within the Sabaragamuwa, Central, Uva, Southern, and North-central provinces.
* May 13: An ‘Amber’ Advisory for heavy rains was issued, with very heavy showers exceeding 200 mm likely in some places within the Western and Sabaragamuwa provinces, and in the Puttalam, Galle, and Matara districts. Heavy showers of about 100 mm were also expected in some parts of the Northern Province, attributed to a low-pressure area in the vicinity of Sri Lanka.
* May 22, 2026: Very heavy showers exceeding 200 mm are likely in parts of the Western, Sabaragamuwa, and North-western provinces, with falls above 100 mm expected in Galle, Matara, Kandy, and Nuwara-Eliya districts.
* May 28, 2026: Fairly heavy falls of about 75 mm are anticipated in Galle, Matara, Kalutara, and Rathnapura districts, with showers also expected in the Western, Sabaragamuwa, North-western provinces, and Kandy and Nuwara-Eliya districts.
* May 29: Showers or thundershowers will occur at times in the Western, Sabaragamuwa and North-western provinces and in the Galle, Matara, Kandy and Nuwara-Eliya districts. Showers or thundershowers may occur at a few places in the Uva province and in the Ampara and Batticaloa districts after 1.00 pm.
Severe Lightning Advisories and Strong Winds
The Department of Meteorology has issued multiple severe lightning advisories, urging the public to take precautions against temporary strong winds and lightning during thundershowers. From April 2 to April 12, 'Amber' and 'Red' alerts were in effect. 'Amber' advisories were consistently issued from April 13-17, with Red alerts for 14 districts on April 15 and 13 districts on April 16. A Red alert for severe lightning was issued for all provinces of Sri Lanka on April 20.
Recent advisories included:
* April 26: Specific warning for Western and Sabaragamuwa provinces, and Galle, Matara, Kandy, Nuwara-Eliya, and Kurunegala districts.
* April 27: Red alerts for 16 districts and Amber alerts for 9 districts.
* May 2: An 'Amber' advisory for severe lightning was issued, valid until 11:30 p.m., covering most provinces and Anuradhapura district. Thundershowers with severe lightning and temporary localized strong winds were highly likely after 1:00 p.m.
* May 3: A warning for strong lightning was issued, expected after 1 PM and valid until 11:30 PM, covering several provinces and districts including Colombo, Kalutara, Galle, and Matara. Temporary strong winds may accompany the thundershowers.
* May 4: A warning for strong lightning was re-issued, expected after 1 PM and valid until 11:30 PM, covering Central, Sabaragamuwa, Eastern, and Uva provinces, along with Kalutara, Polonnaruwa, Galle, and Matara districts. Fairly strong winds of about 30-40 kmph were also expected at times over the Northern and North-central provinces, and the Hambantota district.
* May 6: The lightning warning was extended to North-Central and North-Western provinces, and Vavuniya, Mullaitivu, Mannar, and Ampara districts.
* May 7: A warning for strong lightning was issued, expected after 1 PM and valid until 11:30 PM, covering Central, Sabaragamuwa, Uva, North-Central, North-Western, Southern, Western, Eastern, and Northern provinces, along with Vavuniya and Trincomalee districts.
* May 11: The lightning warning was re-issued, covering Sabaragamuwa, Central, Uva, North-Central, and Eastern provinces, as well as Kurunegala, Mullaitivu, Mannar, and Vavuniya districts. Additionally, a warning for heavy rain was issued for the Western, Sabaragamuwa, Central, Southern, Uva, North-Western, and Northern provinces, and the Anuradhapura district.
* May 29: Fairly strong winds of about 30-40 kmph can be expected at times over the Western slopes of the central hills, Northern, North-central, North-western and Southern provinces and in the Trincomalee district.
During lightning and thunder, the public is strongly urged to avoid staying outdoors or under trees, and instead seek shelter in a safe building or a closed vehicle. Open areas such as paddy fields, tea estates, sports grounds, and reservoirs should also be avoided, as temporary strong winds may occur during thundershowers. The public is advised to take necessary precautions to minimize lightning-related accidents and to seek assistance from regional disaster management officers in case of an emergency.
Misty Conditions and Sun Directly Overhead
Early morning mist or fog has been anticipated in various parts of the island throughout April and into May. For May 1-2, misty conditions were anticipated in parts of the Central, Sabaragamuwa, North-Central, and Uva provinces, along with the Ampara and Polonnaruwa districts. On May 4, foggy conditions were possible in some areas of the Central, Sabaragamuwa, and Uva provinces, and the Ampara district in the early morning.
The sun's apparent northward relative motion meant it was directly overhead Sri Lankan latitudes from April 5 to April 15, concluding around 12:10 noon on April 15 over areas like Pandatharippu and Thellippalai.
Meteorological Outlook and Sea Conditions
The Director General of the Department of Meteorology predicts that Sri Lanka will receive its usual rainfall by May or June. However, a decrease in rainfall of more than 30% is anticipated during the upcoming Southwest Monsoon, a period noted as the beginning of El Niño in May.
Additionally, a warning has been issued for rough sea conditions and strong winds over the Bay of Bengal and Arabian Sea regions for the next three days from May 13. Wind speeds are expected to reach 40–50 km/h and may temporarily increase up to 60 km/h, making sea areas rough at times. Showers or thundershowers are also likely in sea areas off the coast from Puttalam to Colombo, Galle, and Hambantota.