Please be aware that Tokyo has multiple airports and that these results are for all airports serving the city.
The best month to fly between Tokyo and Singapore is February and the most expensive month to fly is March. (Average prices, based on 238 datapoints.)
The best day to arrive at Tokyo is Monday and it would be best to avoid Friday, as prices are on average 106.73% higher than on Monday. (Average prices, based on 240 datapoints.)
The cheapest airline flying from Tokyo to Singapore is Singapore Airlines. They are 48% cheaper than All Nippon Airways. (Average prices, based on 247 datapoints.)
The best time to fly is at around 8. (Average prices, based on 456 datapoints.)