Smallville
Nielsen rankings

Season
Timeslot (ET/PT)
Network
Premiered
Premiered
Ended
Ended
Rank
Viewers (in millions)
Season
Timeslot (ET/PT)
Network
Date
Premiere Viewers (in millions)
Date
Finale viewers (in millions)
Rank
Viewers (in millions)
1 (2001–02)
Tuesday 9/8C
The WB
October 16, 2001
8.40
May 21, 2002
6.00
115
5.90
2 (2002–03)
Tuesday 9/8C
The WB
September 24, 2002
8.70
May 20, 2003
7.50
113
6.30
3 (2003–04)
Wednesday 8/7C
The WB
October 1, 2003
6.80
May 19, 2004
5.92
141
4.96
4 (2004–05)
Wednesday 8/7C
The WB
September 22, 2004
6.07
May 18, 2005
5.47
124
4.40
5 (2005–06)
Thursday 8/7C
The WB
September 29, 2005
5.90
May 11, 2006
4.85
117
4.70
6 (2006–07)
Thursday 8/7C
The CW
September 28, 2006
4.96
May 17, 2007
4.14
125
4.10
7 (2007–08)
Thursday 8/7C
The CW
September 27, 2007
5.18
May 15, 2008
3.85
175
3.77
8 (2008–09)
Thursday 8/7C
The CW
September 18, 2008
4.34
May 14, 2009
3.13
152
3.74
9 (2009–10)
Friday 8/7C
The CW
September 25, 2009
2.58
May 14, 2010
2.45
129
2.38
10 (2010–11)
Friday 8/7C
The CW
September 24, 2010
2.98
May 13, 2011
3.02
131
3.19

Question: Which season of Smallville performed the best during it's airing? 
Answer: Over ten seasons the Smallville averaged, million viewers per episode, is with season two's highest rating of 6.3 million.