Dry ice does not actually melt but instead dry ice sublimates and evaporates.
When it comes to dry ice the dry ice cannot and does not melt but instead the dry ice changes directly from a solid to a gas a process called sublimation.
Ice can sublimate at -10 F degrees or even below in some cases.
Especially dry ice which can sublimate at -100 F degrees.
Ice can and does sometimes evaporate without melting into a liquid first.
When ice evaporates without melting into liquid the process is known as sublimation.
Dry ice is a great example of ice that mostly evaporates without melting and it looks like steam when the sublimation of the ice is occurring.
The process of sublimation is most often used to describe the process of snow and ice changing into water vapor in the air without first melting into water.
"Dry ice" is actually solid, frozen carbon dioxide, which happens to sublimate, or turn to gas, at a chilly -78.5 °C (-109.3°F)
Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state.
An example of Sublimation in the picture below of dry ice going through the process of sublimation which is the process of ice evaporating without melting.