<P> 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 . </P> <P> In July 2017, cast from the series appeared at San Diego Comic - Con International to promote the season, where exclusive footage was shown . During the panel, a trailer for the season was shown, with James Whitbrook at io9 feeling that despite the "grim" tone, there was "some fun signs of the team coming together to protect the city without (Barry),...Sprinkle in a few wacky things, like, say a goddamn Samuroid ripped straight from the comics, and ladies and gents, you've got a good season of The Flash lined up ." Ben Pearson with / Film felt seeing Iris West deal with the absence of Barry was "a nice change of pace for that character", but anticipated that "Barry (would) be back two or three episodes in at the latest ." Collider's Allison Keene also noted Iris "getting an actual storyline" with Barry gone, and similarly presumed that he "(would) be back in the fold by the end of the first episode" alike to Flashpoint in the third season . She added, "There are some new foes, lots of action, plenty of tech--it's great!" </P> <Table> <Tr> <Th> No . </Th> <Th> Title </Th> <Th> Air date </Th> <Th> Rating / share (18--49) </Th> <Th> Viewers (millions) </Th> <Th> DVR (18--49) </Th> <Th> DVR viewers (millions) </Th> <Th> Total (18--49) </Th> <Th> Total viewers (millions) </Th> </Tr> <Tr> <Td> </Td> <Td> "The Flash Reborn" </Td> <Td> October 10, 2017 </Td> <Td> 1.1 / 4 </Td> <Td> 2.84 </Td> <Td> 0.7 </Td> <Td> 1.92 </Td> <Td> 1.8 </Td> <Td> 4.77 </Td> </Tr> <Tr> <Td> </Td> <Td> "Mixed Signals" </Td> <Td> October 17, 2017 </Td> <Td> 0.9 / 4 </Td> <Td> 2.54 </Td> <Td> 0.8 </Td> <Td> 1.82 </Td> <Td> 1.7 </Td> <Td> 4.36 </Td> </Tr> <Tr> <Td> </Td> <Td> "Luck Be a Lady" </Td> <Td> October 24, 2017 </Td> <Td> 1.0 / 4 </Td> <Td> 2.62 </Td> <Td> 0.8 </Td> <Td> 1.84 </Td> <Td> 1.8 </Td> <Td> 4.46 </Td> </Tr> <Tr> <Td> </Td> <Td> "Elongated Journey Into Night" </Td> <Td> October 31, 2017 </Td> <Td> 0.7 / 3 </Td> <Td> 1.99 </Td> <Td> 0.7 </Td> <Td> 1.79 </Td> <Td> 1.4 </Td> <Td> 3.79 </Td> </Tr> <Tr> <Td> 5 </Td> <Td> "Girls Night Out" </Td> <Td> November 7, 2017 </Td> <Td> 0.9 / 4 </Td> <Td> 2.38 </Td> <Td> 0.8 </Td> <Td> 1.84 </Td> <Td> 1.7 </Td> <Td> 4.22 </Td> </Tr> <Tr> <Td> 6 </Td> <Td> "When Harry Met Harry ..." </Td> <Td> November 14, 2017 </Td> <Td> 1.0 / 4 </Td> <Td> 2.46 </Td> <Td> 0.7 </Td> <Td> 1.83 </Td> <Td> 1.7 </Td> <Td> 4.29 </Td> </Tr> <Tr> <Td> 7 </Td> <Td> "Therefore I Am" </Td> <Td> November 21, 2017 </Td> <Td> 0.8 / 3 </Td> <Td> 2.20 </Td> <Td> 0.8 </Td> <Td> 2.08 </Td> <Td> 1.6 </Td> <Td> 4.28 </Td> </Tr> <Tr> <Td> 8 </Td> <Td> "Crisis on Earth - X, Part 3" </Td> <Td> November 28, 2017 </Td> <Td> 1.0 / 4 </Td> <Td> 2.82 </Td> <Td> 0.7 </Td> <Td> 1.83 </Td> <Td> 1.7 </Td> <Td> 4.64 </Td> </Tr> <Tr> <Td> 9 </Td> <Td> "Don't Run" </Td> <Td> December 5, 2017 </Td> <Td> 0.8 / 3 </Td> <Td> 2.22 </Td> <Td> 0.6 </Td> <Td> 1.45 </Td> <Td> 1.4 </Td> <Td> 3.67 </Td> </Tr> <Tr> <Td> 10 </Td> <Td> "The Trial of The Flash" </Td> <Td> January 16, 2018 </Td> <Td> 0.8 / 3 </Td> <Td> 2.51 </Td> <Td> 0.7 </Td> <Td> 1.55 </Td> <Td> 1.5 </Td> <Td> 4.06 </Td> </Tr> <Tr> <Td> 11 </Td> <Td> "The Elongated Knight Rises" </Td> <Td> January 23, 2018 </Td> <Td> 0.7 / 3 </Td> <Td> 2.12 </Td> <Td> 0.7 </Td> <Td> 1.69 </Td> <Td> 1.4 </Td> <Td> 3.81 </Td> </Tr> <Tr> <Td> 12 </Td> <Td> "Honey, I Shrunk Team Flash" </Td> <Td> January 30, 2018 </Td> <Td> 0.9 / 3 </Td> <Td> 2.60 </Td> <Td> 0.8 </Td> <Td> 1.84 </Td> <Td> 1.7 </Td> <Td> 4.43 </Td> </Tr> <Tr> <Td> 13 </Td> <Td> "True Colors" </Td> <Td> February 6, 2018 </Td> <Td> 0.8 / 3 </Td> <Td> 2.28 </Td> <Td> 0.9 </Td> <Td> 2.00 </Td> <Td> 1.7 </Td> <Td> 4.28 </Td> </Tr> <Tr> <Td> 14 </Td> <Td> "Subject 9" </Td> <Td> February 27, 2018 </Td> <Td> 0.7 / 3 </Td> <Td> 2.12 </Td> <Td> 0.8 </Td> <Td> 1.86 </Td> <Td> 1.5 </Td> <Td> 3.98 </Td> </Tr> <Tr> <Td> 15 </Td> <Td> "Enter Flashtime" </Td> <Td> March 6, 2018 </Td> <Td> 0.7 / 3 </Td> <Td> 2.04 </Td> <Td> 0.8 </Td> <Td> 1.83 </Td> <Td> 1.5 </Td> <Td> 3.87 </Td> </Tr> <Tr> <Td> 16 </Td> <Td> "Run, Iris, Run" </Td> <Td> March 13, 2018 </Td> <Td> 0.7 / 3 </Td> <Td> 2.09 </Td> <Td> 0.7 </Td> <Td> 1.58 </Td> <Td> 1.4 </Td> <Td> 3.67 </Td> </Tr> <Tr> <Td> 17 </Td> <Td> "Null and Annoyed" </Td> <Td> April 10, 2018 </Td> <Td> 0.6 / 2 </Td> <Td> 1.82 </Td> <Td> 0.7 </Td> <Td> 1.64 </Td> <Td> 1.3 </Td> <Td> 3.47 </Td> </Tr> <Tr> <Td> 18 </Td> <Td> "Lose Yourself" </Td> <Td> April 17, 2018 </Td> <Td> 0.7 / 3 </Td> <Td> 1.88 </Td> <Td> 0.6 </Td> <Td> 1.54 </Td> <Td> 1.3 </Td> <Td> 3.43 </Td> </Tr> <Tr> <Td> 19 </Td> <Td> "Fury Rogue" </Td> <Td> April 24, 2018 </Td> <Td> 0.6 / 2 </Td> <Td> 1.90 </Td> <Td> 0.7 </Td> <Td> 1.61 </Td> <Td> 1.3 </Td> <Td> 3.51 </Td> </Tr> <Tr> <Td> 20 </Td> <Td> "Therefore She Is" </Td> <Td> May 1, 2018 </Td> <Td> 0.6 / 2 </Td> <Td> 1.70 </Td> <Td> 0.8 </Td> <Td> 1.62 </Td> <Td> 1.4 </Td> <Td> 3.31 </Td> </Tr> <Tr> <Td> 21 </Td> <Td> "Harry and the Harrisons" </Td> <Td> May 8, 2018 </Td> <Td> 0.7 / 3 </Td> <Td> 1.74 </Td> <Td> 0.6 </Td> <Td> 1.52 </Td> <Td> 1.3 </Td> <Td> 3.26 </Td> </Tr> <Tr> <Td> 22 </Td> <Td> "Think Fast" </Td> <Td> May 15, 2018 </Td> <Td> 0.7 / 3 </Td> <Td> 1.93 </Td> <Td> TBD </Td> <Td> TBD </Td> <Td> TBD </Td> <Td> TBD </Td> </Tr> <Tr> <Td> 23 </Td> <Td> "We Are the Flash" </Td> <Td> May 22, 2018 </Td> <Td> 0.8 / 4 </Td> <Td> 2.16 </Td> <Td> TBD </Td> <Td> TBD </Td> <Td> TBD </Td> <Td> TBD </Td> </Tr> </Table> <Tr> <Th> No . </Th> <Th> Title </Th> <Th> Air date </Th> <Th> Rating / share (18--49) </Th> <Th> Viewers (millions) </Th> <Th> DVR (18--49) </Th> <Th> DVR viewers (millions) </Th> <Th> Total (18--49) </Th> <Th> Total viewers (millions) </Th> </Tr>

The flash season 4 episode 19 release date