In general, when booking your flight to Jeddah, July is the cheapest month on average.
Most flyers found that booking flight tickets 51 days in advance of their planned departure date is, on average, the best time to get cheap flights to Jeddah.
From most locations, the cheapest flights to Jeddah are found on a Monday. Booking a Thursday departure is usually the most expensive.
On average you can find the best deals on plane tickets to Jeddah when looking for flights with midday departure times.