In general, when looking for the cheapest flight to Guangzhou, try to choose a flight departing in September for the best deal.
In general, most flyers find the cheapest time to book a flight to Guangzhou is about 58 days prior.
From most locations, the cheapest flights to Guangzhou are found on a Tuesday. Booking a Saturday departure is usually the most expensive.
On average you can find the best deals on plane tickets to Guangzhou when looking for flights with afternoon departure times.