Yes it is. You will need to use a porch and deck paint. I like the alkyd, oil base, type. You should do a little cleaning with a mild soap and garden hose to remove and dirt or dust, any oily or stained areas will need additional cleaning.
Sanding lightly with 120 grit paper is a good idea but not completely necessary. A sanding will help assure a good bond.
Don't use a standard house paint, this will peel quickly. Plus, I haven't had good success with the acrylic porch and deck products.