Please be aware that Taipei has multiple airports and that these results are for all airports serving the city.
The best month to fly between Taipei and Hong Kong is March and the most expensive month to fly is August. (Average prices, based on 4021 datapoints.)
The best day to arrive at Taipei is Wednesday and it would be best to avoid Tuesday, as prices are on average 27.22% higher than on Wednesday. (Average prices, based on 3993 datapoints.)
The cheapest airline flying from Taipei to Hong Kong is China Airlines. They are 33% cheaper than EVA Air. (Average prices, based on 4044 datapoints.)
The best time to fly is at around 22. (Average prices, based on 6612 datapoints.)