Does UV radiation affect heat stress?

A day after ultraviolet (UV) radiation spiked to extreme levels, UV readings dropped to mostly moderate and high levels on March 28, with a peak to very high levels around 1pm and 3pm.

- Shabana Begum

On March 27, UV index readings peaked at 12 on the extreme band at about 12.45pm. On March 28, the highest reading was 10 on the “very high” band at 1.15pm.

The lower UV index levels, compared with the day before, could be due to some overcast skies as parts of the island saw showers in the afternoon.

UV radiation refers to invisible rays that are emitted by the sun, with clouds able to block the rays from reaching the earth’s surface.

The highest UV Index reading so far in 2024 is 14, recorded at 1.30pm on Feb 15, the Meteorological Service Singapore (MSS) said in response to queries. The maximum level on the UV index is 15.

So far in March, 22 days have seen extreme UV levels, with the index reaching up to 13 on several days between noon and 2pm, added MSS, which is under the National Environment Agency (NEA).

Heat stress levels have remained low and moderate on March 27 and 28, indicating that UV and heat are affected by different factors.

What is the UV index?