What is the UV index in Surabaya today?

See today's UV index for Surabaya hour by hour above. The UV index is highest around solar noon and depends on the season, the weather and how high the sun rises above the horizon.

When is the UV index highest?

The UV index peaks around solar noon, typically between 12:00 and 15:00, when the sun is highest in the sky. About two-thirds of the day’s total UV falls between 10:00 and 16:00.

When should you use sunscreen?

The WHO recommends sun protection whenever the UV index is 3 or higher. Use sunscreen of at least SPF 30, seek shade around midday, and wear sunglasses and a hat when UV is high.

UV Index in Surabaya Today

September 4, 2026 · Surabaya, Indonesia

2,374,658 people

See today's UV index in Surabaya hour by hour below. The UV index shows how strong the sun's ultraviolet radiation is — the higher the number, the faster skin can burn. Values are calculated for Surabaya's coordinates and updated daily.

UV now · 13:00

9Very high

Extra protection needed

Peak today12at 11:00

Protect yourself07:41–14:56UV 3 or above

Time to burn~15 minfair skin, unprotected

Hour by hour

Protection windowClear sky

Remember today

Sunscreen SPF 50+
Sunglasses
Hat
Shade at midday
Cover up

Daylight: sunrise 05:30 – sunset 17:29

Tomorrow: UV 13 at its peak around 11:00

Calculate for Surabaya Use my location

The UV index in Surabaya peaks at 12 (extreme) around 11:00 today. Sun protection is recommended between 07:41 and 14:56, while the index stays at 3 or above. Tomorrow the index is forecast to peak at 13 around 11:00.

UV index in Surabaya hour by hour

Time	UV index	Level
05:00	0	Low
06:00	0.2	Low
07:00	1.3	Low
08:00	3.8	Moderate
09:00	7	High
10:00	10	Very high
11:00	11.6	Extreme
12:00	11.2	Extreme
13:00	9	Very high
14:00	5.8	Moderate
15:00	2.8	Low
16:00	0.8	Low
17:00	0.1	Low
18:00	0	Low

UV index in Surabaya

Surabaya lies at 7°S. The midday sun reaches 75.4° above the horizon in Surabaya today, and twice a year it passes straight overhead. Elevation is what sets the ceiling for UV, and over Surabaya it is so steep that the rays take the shortest possible path through the atmosphere, and the index can reach extreme values.

What is the UV index?

The UV index is an international scale describing the strength of the sun's ultraviolet radiation at ground level. It starts at 0 and is effectively open-ended — at mid-latitudes it rarely exceeds 8, while in the tropics and high in the mountains it can pass 11. The higher the number, the less time it takes to get sunburnt.

The UV index depends mainly on how high the sun is in the sky. That is why it peaks around solar noon and is greatest in summer near the longest day of the year. Clouds, ozone, altitude and reflection from snow or water also affect the value.

The WHO UV scale

UV index	Level	Recommendation
0–2	Low	No special protection needed.
3–5	Moderate	Use sunscreen (SPF 30+), seek shade around midday.
6–7	High	Sunscreen, hat and sunglasses. Avoid the sun 12:00–15:00.
8–10	Very high	Extra protection. Limit midday sun exposure.
11+	Extreme	Avoid the sun at midday. Full protection required.