WeatherWeather Science


Colorado alpenglow: The phenomenon that makes some mountain sunrises, sunsets so magical

The amazing optical phenomenon, explained.
Posted at 2:35 PM, Feb 06, 2024
and last updated 2024-02-06 16:35:54-05

DENVER — Have you ever wondered why viewing the sunrise or sunset in the Centennial State appears to be more majestic than anywhere else you've been?

It’s likely due to an optical phenomenon called alpenglow. Never heard of it? You have probably seen it numerous times.


Alpenglow is indirect sunlight, which happens just before sunrise or just after sunset, when the sun is below the horizon. On the ground, you can't see the sun. The glow we see over the mountains is the light from the sun, reflected from particles in the atmosphere.


The effect tends to happen more often in late fall and throughout the winter in mountain climates like Colorado. You have to have the perfect conditions for that to happen, which include cold weather, the right amount of cloud cover and sun angle.