Lightning Observation

Basics of Lightning There are two common types of lightning: cloud-to-ground (“G”) and cloud-to-cloud lightning (“C”) strikes.

Cloud-to-ground lightning occurs when there are electrical discharges between a cloud and ground. Cloud-to-cloud lightning consists of cloud flashes, which are electrical discharges within a single cloud or between different clouds. Cloud-to-cloud lightning often, though not always, precedes the potentially more dangerous cloud-to-ground lightning.

Most lightning strokes occur within 5-6 km of a thunderstorm cloud. In the absence of a thunderstorm in a location, lightning strokes from a distant thunderstorm cloud more than 10 km away could still affect that location. For more information on thunderstorms and lightning, please refer to MSS LEARN page on lightning.

The lightning information is based on data from MSS' Lightning Detection System (LDS). This system comprises a network of five lightning sensors located across the island.

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Accuracy The average location accuracy for cloud-to-ground lightning detected within Singapore varies between 200 m to 2 km. For cloud-to-cloud lightning, the average location accuracy is around 2 km.

The lightning detection efficiency within Singapore is estimated to range between 90% and 95% when all sensors are operational. The location accuracy is reduced if there is a reduction in number of operating sensors within the network. There is no guarantee that all lightning occurrence can be detected, and false detection of lightning strokes may also occur.

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Data Frequency & Timeliness Lightning information is subject to data processing and network transfer speeds. The data displayed on data.gov.sg is updated at 2-minute intervals. There is typically a delay of a few minutes in the data transmission.

The reliability and availability of the information is also dependent on telecommunication and power services, which could disrupt the data flow. Occasionally, technical issues may cause gaps in the data. The information provided may be subject to subsequent correction if necessary.