Title: The Flash (season 8)
Content:  The season premiered on The CW on November 16, 2021. Two weeks before the premiere, on November 5, 2021, the CW announced their midseason schedule for their shows, announcing that after "Armageddon", The Flash will air on Wednesdays starting March 9, 2022. Prior to the season premiere, Eric Wallace confirmed that the season would only have 18 episodes.
Title: The Flash (season 6)
Content:  The season premiered on October 8, 2019, in the United States on The CW. It was initially set to run for 22 episodes, but as production on the season could not continue due to the COVID-19 pandemic, the nineteenth episode was later announced as the season finale.
Title: The Flash (season 7)
Content:  The seventh season premiered on March 2, 2021, delayed from its previous date of February 23, 2021. Despite premiering much later than previous seasons, it was not expected to have a much shorter episode count. In September 2020, Wallace said the number of episodes for the season had not yet been decided, and that would depend on when the season would begin filming safely. On May 25, 2021, it was confirmed that the season 7 finale would be on July 20, and that the season would have only 18 episodes, meaning that season 7 is the shortest season yet.
Title: The Flash (season 5)
Content:  The season premiered on The CW in the United States on October 9, 2018. The annual crossover episode swapped time-slots with Supergirl for that week and aired on Sunday, December 9.
Title: The Flash (2014 TV series)
Content:  second. On April 2, 2018, The CW renewed the series for a fifth season, which premiered on October 9, 2018. On January 31, 2019, The CW renewed the series for a sixth season, which premiered on October 8, 2019. On January 7, 2020, the series was renewed for a seventh season, which premiered on March 2, 2021. In April 2020, Gustin, who had been contracted for seven seasons, said there had been discussions about renewing the series for eighth and ninth seasons, but those were stalled due to the COVID-19 pandemic. On February 3, 2021, the series was renewed for an eighth season which premiered on November 16, 2021.
Title: The Flash (season 7)
Content:  The episode that would have been season six's 20th was 90% filmed before being announced as the season seven premiere. The season was scheduled to begin filming on October 1, 2020. However, by September 29, the start of filming was temporarily postponed, because of delays in receiving COVID-19 test results for the cast and crew. Filming later began on October 9. On November 29, 2020, filming was temporarily suspended following a member of the production testing positive for COVID-19, and resumed by mid-December at Cloverdale. Filming concluded on May 22, 2021.
Title: The Flash (2014 TV series)
Content:  The Flash was screened at the Warner Bros. Television and DC Entertainment panel at San Diego Comic-Con International in July 2014. The series officially premiered on The CW on October 7, 2014, during the 2014–15 television season and also premiered in Canada on the same night. The second episode was screened at New York Comic Con on October 9, 2014, as a way to repay the viewers that watched the series' premiere episode. The series premiered in the United Kingdom and Ireland on October 28, 2014, and in Australia on December 3, 2014.
Title: The Flash (season 1)
Content:  The Flash was screened at the Warner Bros. Television and DC Entertainment panel at San Diego Comic-Con International in July 2014. The series officially premiered on The CW on October 7, 2014, during the 2014–15 television season and also premiered in Canada on the same night. The second episode was screened at New York Comic Con on October 9, 2014, as a way to repay the viewers that watched the series' premiere episode. The series premiered in the United Kingdom and Ireland on October 28, 2014, and in Australia on December 3, 2014.
Title: The Flash (season 3)
Content:  In October 2016, it was announced that the season would be available for streaming on Netflix eight days after the season finale, part of the new CW-Netflix deal. The five most recent episodes are available to stream for free on the new mobile CW app, instead of on Hulu like the previous two seasons. The season began streaming on Netflix on May 31, 2017, and was released on Blu-ray and DVD in Region 1 on September 5, 2017.
Title: The Flash (season 4)
Content:  The season began airing on October 10, 2017, on The CW in the United States, and on CTV in Canada. The season concluded on May 22, 2018. Sky One acquired the rights to air the season in the UK & Ireland, airing it alongside the other Arrowverse shows. The season premiered October 17.

Question: when will the next episode of flash be aired?
Answer: May 15, 2018.