How does weather affect fall foliage?

Q: How does weather affect fall foliage?

A: Temperature, light and precipitation all have an affect on foliage color and duration. Cooler than normal nighttime temperatures will produce brighter red colors in maple trees. Early frost will lessen the bright red color on trees. Rainy or cloudy days tend to increase the intensity of fall colors. The best time to enjoy the autumn color would be on a clear, dry and cool day.