INTERACTIVE: KLIA tops Subang in lightning days for a decade, but 2025 bucks the trend

By SHYAFIQ DZULKIFLI

PETALING JAYA: Kuala Lumpur International Airport (KLIA) weather station recorded more lightning days than Subang for most of the past decade, but the long-running trend reversed in 2025.

According to data by the Malaysia Meteorological Department (MetMalaysia), Subang registered 294 lightning days last year, surpassing KLIA’s 279 days.

However, from 2015 to 2024, KLIA recorded the most lightning days, with more than 300 lightning days every year.

 

KLIA’s records peaking at 342 days in 2015 and 341 days in both 2017 and 2020.

This means lightnings were observed in KLIA on over 90% of days in those years.

 

In comparison, Subang’s highest annual total during the same period was 315 days in 2017, while its figures generally remained below those recorded in Sepang, except in 2025.

MetMalaysia director general Dr Mohd Hisham Mohd Anip said the difference between KLIA and Subang is largely driven by geographical factors, rather than airport operations or surrounding infrastructure.

He explained that KLIA’s location closer to coastal areas compared with Subang increases the likelihood of lightning development.

“KLIA’s location nearer to the coast than Subang increases the likelihood of more frequent lightning occurrences being recorded at the station,” he said.

Lightning occurrences at weather stations are still recorded through direct visual observation by trained weather officers, and any visible lightning is counted as a lightning day.

Dr Mohd Hisham said lightning that is recorded may originate from storms more than 10km away from the observation station, meaning storm systems in nearby areas can also contribute to a station’s lightning totals.

In 2023, MetMalaysia introduced the Lightning Detection and Alert System (LDAS) at KLIA, enabling real-time monitoring of thunderstorm and lightning activity within the airport’s airspace and surrounding areas.

"The system provides early warnings and continuous weather updates to airport authorities and airline operators, allowing operations to be adjusted when necessary while ensuring passenger safety," he said.

Dr Mohd Hisham also stressed that aviation weather services at KLIA comply with standards set by the International Civil Aviation Organization (ICAO) and are subject to regular audits.

Monitoring, forecasting and dissemination of aviation weather information are carried out in accordance with ICAO Annex 3 – Meteorological Service for International Air Navigation, ensuring that Malaysia’s main gateway meets international safety requirements.

Experts say the consistently high lightning counts recorded at Malaysian stations are not unusual, given the country is widely recognised as one of the most lightning-prone regions in the world due to its equatorial location and regional geography.

Universiti Malaya meteorologist Professor Emeritus Datuk Dr Azizan Abu Samah said the Maritime Continent (MC), which includes Malaysia, Indonesia and Papua New Guinea, is considered the most active lightning hotspot globally.

“We have lots of thunderstorms, so our area is very prone to lightning strikes. Satellite climatology and ground-based networks consistently show this region as among the most active in the world,” he said.

Azizan said the region’s maze of islands, narrow seas, and complex coastlines creates strong daily land–sea breeze circulations and repeated storm triggering.

He added that the MC sits on the Indo-Pacific warm pool that lead to high evaporation of water and helps in developing highly electrified thunderstorm clouds.

Universiti Malaysia Terengganu's Faculty of Marine Sciences and Environment senior lecturer Dr Chung Jing Xiang said Malaysia’s position near the equator also places it within the rising branch of the Hadley cell circulation, where upward-moving warm, moist air favours thunderstorm formation.

“When air is warm and moist, it becomes more buoyant and rises more easily. Rising air and moisture are the key ingredients for thunderstorm clouds to form, which increases lightning potential in equatorial regions like ours,” he said.