How UV Index Works
UV Index is a simple scale for how strong the sun's ultraviolet radiation is at a place and time. Higher numbers mean you should be more deliberate about protection.
Reading the scale
Use normal outdoor awareness.
Consider protection if you will be outside longer.
Apply sunscreen and plan to reapply.
Use extra caution and seek shade when practical.
Limit exposure and use strong protection.
What Sunclub shows
Sunclub pairs the number with a severity label, location context, forecast rows, and a short next step such as reapplying sunscreen every two hours during high exposure. Live UV availability can vary by location, permissions, network access, and Apple Weather.
Why values change
UV can shift with time of day, clouds, season, elevation, shade, and location. Forecasts are useful planning signals, not a guarantee of exact exposure.
How to use it
Check UV before longer outdoor time, log sunscreen when you apply, and follow your sunscreen's directions for reapplication, sweating, swimming, and coverage.
When data is unavailable
Manual logging still works. Sunclub can fall back to the latest available context and let you continue tracking your habit.