Please be aware that Beijing has multiple airports and that these results are for all airports serving the city.
The best month to fly between Beijing and Guangzhou is August and the most expensive month to fly is March. (Average prices, based on 387 datapoints.)
The best day to arrive at Beijing is Tuesday and it would be best to avoid Sunday, as prices are on average 34.88% higher than on Tuesday. (Average prices, based on 787 datapoints.)
The best time to fly is at around 8. (Average prices, based on 435 datapoints.)