Chelsea have won only one and lost two of their five Barclays Premier League matches away so far this season ahead of the trip to Upton Park, where the Hammers claimed a 3-1 fixture last season.
A second away defeat of the season at Newcastle was followed by a controversial home draw with West Brom which leaves Mourinho's men seeking their first Premier League win of November at the third attempt in east London prior to matches at Sunderland, Stoke and Arsenal before the year's end.
"We have to do better," Mourinho said.
"Our fixtures until now were not the easiest ones, especially when we speak about matches away. We've played already against two title contenders (Manchester United and Tottenham, both draws).
"We've had difficult matches, but of course we want to do better and we need to get more points in the next five matches away than we did in the first five matches (away)."
Mourinho was highly critical of his players' performance at Newcastle but does not know what to expect of his side following the international break.
And the Portuguese insists his side must have the right mindset going into the congested festive period.
He said: "These matches, when they come from national teams are always a question mark for us. But we have to speak, we have to meet, we have to understand that this is an important period.
"November, December, consecutive matches from now, no stop because of national teams. We need points.
"In this moment we are in the Champions League area. We are fourth. We are four points from the leader. We have to try. This situation gets better or at least it doesn't get worse. We need points."
Mourinho is not a fan of the international break and, for the past 11 days, Mourinho has had just four of his first-team squad available in Cesar Azpilicueta, Ryan Bertrand, John Terry and Demba Ba. Mourinho would not be drawn on whether Terry should make an England return.
Azpilicueta could continue at left-back, even though Ashley Cole is considered fit despite going off during England's loss to Germany on Tuesday with an ongoing rib problem. Fernando Torres is still out.
Mourinho expects his side will have to take the initiative against a Hammers side which has packed the midfield and gone without a striker in recent weeks.
West Ham boss Sam Allardyce has already spoken highly of Newcastle's tactics in their win over Chelsea and employed similar tactics in the 3-0 win at Tottenham.
"Many teams in the Premier League are playing very defensive football, are thinking of trying to stop the opponent to play and after that to see what happens," Mourinho said.
"That is giving some good results to some different teams against the considered best teams in the competition.
"No criticism about that. They are defensive and they give difficult matches to the big teams.
"That's why everybody is losing points. That's why nobody is really dominant in this league.
"That's why everybody keeps losing points but keeps in contact in the top part of the table.
"That's why this league has emotion every weekend, so I'm expecting a very difficult match.
"It always was in my time and it continues to be a hard match there. We have to be on the top of our game if we want a result."