The result allowed Barca to go four points clear at the top of the table.
But Mourinho insists that all is still to play for.
"This draw is two points lost, but there is the entire second half of the season to be played," he said.
"I think we have done well so far. We have won 15 matches, lost one and drawn two, but it isn't enough to be champions. We hope to improve in the second half of the season."
On the game with the league's bottom side, which Madrid nearly won when a 94th-minute free-kick from Cristiano Ronaldo thumped the bar, the coach added: "We didn't play at the rhythm we are used to during the first half.
"Almeria defended very well, were very organized and played up to their potential. Hats off to them for earning a very important point."
"Under normal conditions, if referees do their job with the same criteria for every team, La Liga is anybody's. We are halfway through the season and we can make up this deficit."