UV Index in Wyoming (WY)
Wyoming has an average annual UV index of 5.2, classified as High . UV levels peak in July with an average of 10.6, reaching Extreme levels. During peak months, unprotected fair skin can burn in as little as 9 minutes. SPF 50+ sunscreen, protective clothing, and shade are strongly recommended. UV ranges from 5.2 in Sheridan to 6.6 in Laramie.
Monthly UV Index by City in Wyoming
The heatmap below shows the monthly average UV index for 5 cities in Wyoming. Colors range from green (low UV, 0-2) through yellow (moderate, 3-5), orange (high, 6-7), red (very high, 8-10), to purple (extreme, 11+). Hover over any cell to see the exact value.
| City | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Avg | Peak |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Laramie | 3 | 4 | 6 | 7 | 9 | 11 | 11 | 10 | 8 | 5 | 3 | 2 | 6.6 | June |
| Cheyenne | 2 | 3 | 5 | 7 | 9 | 10 | 11 | 10 | 7 | 5 | 3 | 2 | 6.2 | July |
| Jackson | 2 | 3 | 5 | 7 | 9 | 10 | 11 | 10 | 7 | 5 | 2 | 1 | 6 | July |
| Casper | 2 | 3 | 5 | 6 | 8 | 10 | 10 | 9 | 7 | 4 | 2 | 1 | 5.6 | June |
| Sheridan | 1 | 2 | 4 | 6 | 8 | 9 | 10 | 9 | 6 | 4 | 2 | 1 | 5.2 | July |
Sun Protection Recommendations for Wyoming
Based on the peak UV index of 10.6 (Extreme) during July, here are the recommended sun safety measures for Wyoming residents and visitors:
Extreme UV — Extreme risk. Unprotected skin and eyes can burn in minutes.
- Apply SPF 50+ broad-spectrum sunscreen every 60-90 minutes
- Wear full protective clothing, hat, and UV-blocking sunglasses
- Avoid the sun between 10 AM and 4 PM
- Stay in the shade as much as possible
- Take all precautions — UV at this level is dangerous
- White sand, water, and high altitude amplify exposure
Recommended sunscreen: SPF 50+ (reapply frequently)
Estimated Sunburn Times in Wyoming (July Peak)
Approximate time to first sunburn at peak UV (10.6) without sunscreen, by skin type:
| Skin Type | Description | Time to Burn |
|---|---|---|
| Type I | Very Fair | 6 min (high risk) |
| Type II | Fair | 9 min (high risk) |
| Type III | Medium | 19 min |
| Type IV | Olive | 28 min |
| Type V | Brown | 38 min |
| Type VI | Dark Brown/Black | 47 min |
Seasonal UV Patterns in Wyoming
Wyoming's UV index follows a seasonal pattern, with the lowest levels in December and January and the highest in July. Here are the state-average UV levels by month:
Summer months in Wyoming consistently reach Very High or Extreme UV levels. Outdoor workers, athletes, and beachgoers should take extra precautions from May through September.
How Wyoming Compares to Other States
Below is a comparison of Wyoming with five states that have similar average UV index levels. Understanding how your state compares helps put your sun exposure risk in context.
| State | Avg UV | Level | Cities |
|---|---|---|---|
| Wyoming (WY) | 5.2 | High | 5 |
| Tennessee (TN) | 5.2 | High | 5 |
| North Carolina (NC) | 5.3 | High | 6 |
| Kansas (KS) | 5.4 | High | 5 |
| Arkansas (AR) | 5.5 | High | 5 |
| Missouri (MO) | 4.9 | Moderate | 5 |
Skin Cancer Risk Factors
UV radiation is the primary environmental risk factor for skin cancer. While the UV index in Wyoming is only one factor, understanding cumulative exposure is important. Key risk factors include:
- Cumulative UV exposure — total lifetime sun exposure, especially sunburns before age 18
- Skin type — fair skin (Types I-II) has significantly higher risk
- Geographic location — Wyoming's moderate UV levels carry standard risk
- Altitude — higher elevations increase UV exposure significantly
- Outdoor occupation/hobbies — agricultural workers, construction workers, golfers, runners, and beach visitors accumulate more exposure
- Tanning bed use — artificial UV exposure dramatically increases risk
The American Academy of Dermatology recommends annual skin checks for everyone, with more frequent screenings for those with multiple risk factors. Early detection dramatically improves outcomes for all types of skin cancer.
Check UV for Your City
Use our UV index lookup tool to find your specific city in Wyoming, or browse all 50 states to compare UV levels across the country.