In Autumn, New England foliage turns vibrant shades of red, yellow, and orange. Which brings in lots of green—as in the money spent by tourists who flock to the region to witness the explosion of color. Because of fall's economic implications, exactly when the leaf-peeping season will begin is thus a source of constant speculation. Scientists know that factors including frost, heat, rain and drought all affect the timing—but the whole colorful picture is still difficult to accurately predict. Now scientists have picked apart satellite imagery from two New England forest ecosystems collected from 2001 to 2012 to try to get a better handle on exactly what factors influence the autumn leaves. The scientists looked at north eastern highlands and coastal zones. They incorporated devaluable data on chills, frosts and heat, and rain, drought, and flooding. In general, cold, wet and extreme heat made leaves change color sooner.