UV Index in Columbus
Updated: December 6, 2025
Sun Exposure Risk
No protection required. You can safely stay outside.
UV Index Scale
Sun Protection Recommendations
Minimal Protection Needed
You can safely enjoy outdoor activities. Wear sunglasses on bright days.
Recommended Protection Measures
Sunscreen
SPF 30+
Apply generously 15-30 minutes before going outside. Reapply every 2 hours.
Sunglasses
UV400 Protection
Wear sunglasses that block 99-100% of UVA and UVB radiation.
Hat
Wide-brimmed
Wear a hat with at least 3-inch brim to protect face, ears, and neck.
Clothing
UPF-rated fabric
Light, breathable clothing.
Shade
Seek cover
Stay in shade during peak hours (10 AM - 4 PM).
Timing
Plan activities
Schedule outdoor activities before 10 AM or after 4 PM when possible.
Safe Sun Exposure Times
Estimated time until skin damage for untanned, fair skin (Type II)
⚠️ Note: These times are estimates for fair skin. Darker skin types have more natural protection but should still use sunscreen. Times are shorter for children and those with sensitive skin.
UV Radiation Facts
☀️ What is UV Radiation?
Ultraviolet (UV) radiation is invisible rays from the sun that can damage skin and eyes. There are three types: UVA, UVB, and UVC (blocked by atmosphere).
🌡️ UV vs Temperature
UV index is NOT related to temperature. You can get sunburned on cool, cloudy days. UV rays penetrate clouds and reflect off water, snow, and sand.
⏰ Peak Hours
UV radiation is strongest between 10 AM and 4 PM. About 40% of daily UV exposure occurs during these peak hours.
🏔️ Altitude Effect
UV intensity increases by about 10-12% for every 1,000 meters (3,280 feet) increase in altitude.
🏖️ Reflection
Water reflects 25% of UV rays, sand 15%, and snow up to 80%. This doubles your exposure near these surfaces.
👶 Children at Risk
Children under 6 months should avoid direct sun. Most lifetime sun exposure occurs before age 18, increasing skin cancer risk later.
Health Risks of UV Exposure
Short-term Effects
- Sunburn: Red, painful skin that can blister and peel
- Eye Damage: Temporary vision problems, photokeratitis (snow blindness)
- Immune Suppression: Temporary weakening of immune system
- Sun Rash: Itchy red bumps on sun-exposed skin
Long-term Effects
- Skin Cancer: Increased risk of melanoma, basal cell, and squamous cell carcinoma
- Premature Aging: Wrinkles, age spots, leathery skin
- Eye Conditions: Cataracts, macular degeneration
- DNA Damage: Cellular mutations leading to cancer