The type of oil required of Honda vehicles varies and depends on the specific model. Most Civics, for example, require 5W-30, while Accords use 5W-20.
Oil weight is generally set from factory to be reliable in colder temperatures. Since the consistency of the oil changes in colder climates, the weight of the oil must be able to flow appropriately, to avoid damage from the engine.
This has led to Honda vehicles using synthetic 0W-20 weighted oil. This oil is claimed to make the engines on these vehicles last twice as long as their traditional oil weights. However, Honda still recommends using the oil weight specified inside of the owner's manual of each vehicle.