The War of 18-49, Supergirl

CBS Branches Out

Before it became part of the superhero tradition on the CW, Supergirl began its life as an attempt to take that tradition to one of the big four networks. In season one, it aired on CBS, riding a The Big Bang Theory lead-in (4.4) to 12.955 million viewers and a 3.1 viewers for its premiere on October 26, 2015. Then it became the lead-off piece in a three-drama CBS Monday, on a night where the eye has historically aired a powerful comedy block. It fell to 2.2 in week two, then never broke 2.0 again; it settled at mid-1's late in the fall, bounced back up to high-1's in the winter, and got as low as 1.3 in the spring. Most big four shows at this level would've been renewed, but instead CBS opted for a return to Monday comedy, leaving Supergirl season two to the CW.

The CW's Monday Anchor

On the CW, Supergirl stayed in its CBS timeslot on Monday at 8/7c. It only brought half the Plus of its CBS season, but that still made it the #2 show on the network behind The Flash, including a 1.1 for its CW premiere night as well as for its first crossover episode in late November. It was normally around a 0.7 for most of the season, but got as low as 0.5 in the late spring.

Season three brought a return to Monday at 8/7c but another big decline in the ratings; it got a 0.9 for the crossover and a couple 0.6's in January, but was otherwise a steady diet of 0.4's and 0.5's.

Starting a New Night

Then came season four, in which Supergirl was asked to anchor yet another big network experiment; the CW decided to return to programming on Sunday night for the first time in nearly a decade. This resulted in another down season, with mostly 0.3's and the occasional 0.4 (plus a 0.8 for a crossover episode). In season five, Supergirl gave up its anchor duties for the first time, staying on Sunday but at 9/8c, following the new Batwoman series.

The final season of Supergirl saw a move to Tuesday for the first time, where it aired at 9/8c starting in the late spring after The Flash. Most of the final season will actually take place in the late summer and fall of 2021.

Adults 18-49 info by season:

Seas	Year	Slot	Avg	y2y	Lo	Hi	Results	Grade
1	2015-16	Monday 8:00 (CBS)	1.67		1.2	3.1	detail
2	2016-17	Monday 8:00 (CW)	0.72	-57%	0.5	1.1	detail	B+
3	2017-18		Monday 8:00 (CW)	0.51	-30%	0.4	0.9	detail	C+
4	2018-19	Sunday 8:00	0.35	-31%	0.3	0.8	detail	C+
5	2019-20	Sunday 9:00	0.22	-36%	0.1	0.6	detail	C
6	2021	Tuesday 9:00	0.10	-54%	0.1	0.2	detail	C

Historical-adjusted ratings by season:

Seas	Year	A18-49+	Label	Now22	y2y	Lo	Hi	Premiere	Finale
1	2015-16	115	solid	0.59		86	215	215	86
2	2016-17	59	hit(CW)	0.30	-49%	39	94	88	51
3	2017-18	46	hit(CW)	0.24	-22%	35	80	48	41
4	2018-19	37	solid(CW)	0.19	-21%	28	81	48	32
5	2019-20	27	marginal(CW)	0.14	-25%	17	79	45	21
6	2021	16	flop	0.08	-42%	9	23	22	12
AVERAGE:		AVERAGE:	50	hit(CW)
CAREER:		CAREER:	300	utility

The War of 18-49 chronicles the ratings history of veteran primetime series. For more, see the Index.