What substance has the highest albedo?

Fresh snow has the Earth's highest albedo at 0.95. Albedo is a measure of reflectivity. Fresh snow reflects approximately 95 percent of the sun's rays.

Albedo has an effect on temperature. Substances with high albedo will have cooler temperatures. Substances with lower albedo absorb the rays of the sun and have higher temperatures. Asphalt has a very low albedo. This is why it can burn people's feet when they walk on it in the summer. The temperature of many cities is higher than normal due to the presence of surfaces with low albedo. This is known as the "urban heat island effect."