The combined overall household rating for Wednesday night's final presidential debate, in the top 56 local television markets where Nielsen maintains electronic TV meters, was 38.3. 

In comparison, last week's debate between Senators McCain and Obama -- the candidates' second -- received a 42.0 household rating in the top 55 local TV markets.  The candidates' first debate on September 26 received a 34.7 household rating in the top 55 markets.

Wednesday night's championship baseball game between the Los Angeles Dodgers and the Philadelphia Phillies -- aired by FOX, instead of the debate -- may have impacted the debate's ratings.  In the Philadelphia market, where 43.7% of local households tuned in for last week's presidential debate, the debate drew 32% of local households, while the baseball game drew 32.3%. 

In the Los Angeles market, 10.2% of local households watched the game, while 29.2% of households watched the debate -- down slightly from the previous debate, in which 33.7% of L.A. homes tuned in.

Among the top 56 local metered markets, the Baltimore market had the largest TV audience, with a household rating of 49.3, while the Sacramento/Stockton/Modesto, California market again had the lowest household rating: 28.1. 

One rating point equals 1% of the total TV audience in a given market.

View ratings for Nielsen’s 56 top local metered markets.

Coverage of the final debate between Senators John McCain and Barack Obama aired on NBC, CBS, ABC, BBCA, CSPAN, PBS, MSNBC, CNBC, UNIVISION, CNN, and FOX News Channel.

National ratings for Wednesday night’s debate will be available from Nielsen Thursday afternoon.