Backpacker Magazine –
How to Predict the Weather
How they form
Found more than 20,000 feet high, these curly, wispy clouds consist of ice crystals and can form in any season. Cirrus generally appear white but, at dawn and dusk, can take on a rainbow of colors.
What to expect
Don’t confuse cirrus clouds with other high-altitude clouds such as cirrostratus clouds or high, lumpy cirrocumulus clouds. The former signal a good chance of rain or snow within 24 hours, and the latter often indicate cold weather; in the tropics, however, cirrocumulus clouds might mark a hurricane’s approach.
What to do
Milk the weather window: Enjoy a long lunch or tack on another objective.
Subscribe to Backpacker magazine
Sign up for our free weekly e-newsletter