UV index in Alief

Hourly ultraviolet index forecast for Alief, computed for clear sky.

Clear sky value. Thick cloud lowers the real index, but ultraviolet goes through thin cloud and reflects off sand, snow and water.

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Index

Range	What to do
Low (0 to 2)	You can stay outside with no special protection.
Moderate (3 to 5)	Shade around midday, hat, sunglasses and sunscreen.
High (6 to 7)	Avoid the sun between 10 am and 4 pm; SPF 30 or higher.
Very high (8 to 10)	Unprotected skin burns fast; cover up and stay in the shade.
Extreme (11 and above)	Avoid midday sun. Sunburn in minutes.

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How to read this page

How to read the UV index

The scale starts at 0 and has no ceiling: 3 to 5 calls for protection, 8 to 10 is very high, above 11 extreme. The — peak for Alief applies at the Sun’s highest moment, not all day.

Where the data comes from

The series comes from MET Norway (clear-sky UV index parameter), computed for the coordinates of Alief. Licensed CC BY 4.0.

Clear sky, not real sky

The index assumes clear sky: under thick cover the real value in Alief is lower. This page is informational and does not replace medical advice on skin and sun exposure.

Protection in practice

At index 3 or above, the World Health Organization advises shade in the middle of the day, a shirt, a broad-brimmed hat, UV-filtering sunglasses and sunscreen reapplied through the day.

WHO — UV index

Understanding the UV index in Alief

What is the UV index in Alief today?

The UV index series for the coordinates of Alief did not respond just now. The value returns to the top of the page at the next refresh.

Words on this page

UV index

An open-ended scale starting at 0 that measures the strength of ultraviolet radiation able to redden skin. From 3 to 5 protection is already advised, 8 to 10 is very high and above 11 is extreme. It depends on how high the Sun is, on the ozone layer, on altitude and on cloud.

Standard definition by WHO / WMO — Global Solar UV Index · UV index

Ground-level ozone

Ozone formed near the ground when sunlight reacts with exhaust gases and solvents. It is not the ozone layer, which sits kilometres up and protects us: this one irritates the airways and rises on clear, hot, windless days.

Standard definition by U.S. EPA — AQI Technical Assistance Document · Ground-level ozone

Ultraviolet radiation

The invisible part of sunlight with wavelengths below violet. UVB burns skin and is largely filtered by the ozone layer; UVA goes deeper, passes through glass and ages skin. The UV index sums both up by their reddening effect.

Standard definition by WHO / WMO — Global Solar UV Index · Ultraviolet radiation

AQI

The United States Air Quality Index, 0 to 500, which converts each pollutant concentration into a single score and reports the worst one. Up to 50 is good, above 100 it starts to affect sensitive groups, above 150 it affects everyone. The score is not linear in concentration: it follows breakpoints set by the EPA.

Standard definition by U.S. EPA — AQI Technical Assistance Document · AQI

Preliminary data

A measurement published as soon as it is collected, before the agency’s final review. It can be corrected or withdrawn: earthquake magnitudes shift in the first hours, air-quality readings are revised weeks later. Use it to plan your day, not for regulatory or legal purposes.