UV Index in Perth Today
September 27, 2026 · Perth, Australia
1,896,548 people
See today's UV index in Perth 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 Perth's coordinates and updated daily.
UV has dropped for today
Hour by hour
Clouds cut the peak by ~21%Protection windowClear sky
Remember today
- Sunscreen SPF 30+
- Sunglasses
- Hat
- Shade at midday
Daylight: sunrise 06:01 – sunset 18:16
Tomorrow: UV 6 at its peak around 12:00
The UV index in Perth peaks at 6 (high) around 12:00 today. Sun protection is recommended between 09:20 and 15:03, while the index stays at 3 or above. Cloud cover is damping the peak by roughly 21% compared with a clear sky. Tomorrow the index is forecast to peak at 6 around 12:00.
UV index in Perth hour by hour
| Time | UV index | Level |
|---|---|---|
| 06:00 | 0 | Low |
| 07:00 | 0.4 | Low |
| 08:00 | 1.2 | Low |
| 09:00 | 2.7 | Low |
| 10:00 | 3.6 | Moderate |
| 11:00 | 4.4 | Moderate |
| 12:00 | 5.8 | Moderate |
| 13:00 | 5.2 | Moderate |
| 14:00 | 4 | Moderate |
| 15:00 | 3.1 | Moderate |
| 16:00 | 1.3 | Low |
| 17:00 | 0.4 | Low |
| 18:00 | 0 | Low |
| 19:00 | 0 | Low |
UV index in Perth
Perth lies at 32°S. The midday sun reaches 59.5° above the horizon in Perth today, against a yearly ceiling of 81.5°. Elevation is what sets the ceiling for UV, and over Perth 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. |