SUMMER NIGHTS by TWICE has sold 395,532 copies in Korea.
SUMMER NIGHTS certifications and sales
| Country / region | Sales | Certification / source | Certification date / sales as of | |
 Korea |
395,532 | RIAK / Gaon charts | January 2022 |
Korea Sales: 395,532
Certification / note: RIAK / Gaon charts
Certification Date / sales as of: January 2022
|
| Total sales | 395,532 | (in 1 country) |
Total
Sales: 395,532
(in 1 country)
|
Year-end chart performance for SUMMER NIGHTS
| Chart 2018 | Rank | Sales |
 Japanese Albums (Oricon) |
55 | |
| South Korean Albums (Gaon) |
16 | 314,421 |