Currently, the cheapest month to rent a car at Yanbu Airport is March. The most expensive time to rent a car is December. The cheapest prices for each month are shown above, but prices will vary based on availability, how far out you book your rental car, and of course, car type.
Typically, how long you can rent a car for depends on the inventory of the supplier. For Yanbu Airport however, it is certainly possible to rent a car for an entire month.