The Bavarians have won their opening four league games, and hold a five-point lead over titleholders Borussia Dortmund.
Nevertheless, Lahm has urged his team-mates not to get carried away.
"It's way too early to say that Bayern will just cruise to the Bundesliga title. We held a five-point lead last season as well, and still threw it all away. We can't let that happen again this year," Lahm was quoted as saying by TZ.
Lahm then reflected on Saturday's 2-0 win over Schalke, and stressed that Bayern gave their title rivals a clear signal with the victory.
"We definitely gave off a signal, though, in the game versus Schalke. We showed our rivals what we're capable of.
"It was an encounter between last year's runners-up and the number three. It was a big game between two teams that had both won their Champions League game in midweek."
Bayern resume Bundesliga action on Tuesday when they take on Wolfsburg.