UV Index
UV Index
Today's UV index in Longmont, United States 
will be up to 9.8, indicating a very high level of sun exposure for the average person. Check our tips for today to make sure you're safe in the sun.
Last checked: 2025-06-10
With a UV index of 9.8 in Longmont, it's crucial to safeguard your skin from harmful UV rays. Protect yourself by minimizing sun exposure, wearing protective clothing, and applying SPF 30+ sunscreen every 2 hours.
The UV index in Longmont usually ranges from low to moderate, peaking in the summer months. It rarely reaches very high levels, making sun exposure generally safer compared to sunny desert areas.
Longmont experiences four distinct seasons, with cold, snowy winters and warm summers. Spring and fall have mild temperatures and occasional rainfall. Snow is common in winter, while summer often brings thunderstorms.
Compared to nearby Denver and Boulder, Longmont's weather is quite similar due to its close location. It is drier and sunnier than places further east in Colorado. Compared to neighboring states like Nebraska and Wyoming, Longmont is warmer and less humid.
See the UV index hour by hour for Longmont, along with the temperature and how cloudy it is. If the UV level is higher than moderate, it's best to avoid direct sunlight.