The Red Devils are down in eighth ahead of Saturdays clash with Bournemouth at Dean Court but Mourinho is confident that his side will be better placed by the start of 2019.
While United have only managed five wins in the English top flight since the start of the campaign, they will be encouraged after an improved performance last weekend against Everton.
Mourinho has also been boosted by the return of forwards Alexis Sanchez and Jesse Lingard who the Portuguese claims are ready to face the Cherries.
Asked where he hopes United will be placed after December, Mourinho replied: I think we will be in a better position.
I always say that in the end of the season you play 19 matches at home and away and it doesnt matter when but the reality is that the way the fixtures are coming sometimes they have an influence in the moment we had a double fixture away Burnley, Watford now we have a double fixtures away with Bournemouth and Manchester City.
We will have Juventus away before Manchester City, we will have Valencia away before Liverpool in this part of the season we play away against possibly the three biggest candidates for the title, Liverpool, Chelsea, Manchester City so the calendar was not nice to us.
But I think by the end of December, which is the end of the first half of the Premier League, we are not going to be in the position we are now.
We will be in a better position.
Mourinho is confident that United can still finish the season inside the top four despite a disappointing start to the campaign.
Asked about the atmosphere inside the dressing room, Mourinho replied: The mood is fine. Our last couple of weeks was positive, that second half against the Newcastle.
The match against Chelsea, against Juve it was really hard, we fought hard. We had a very positive game against Everton. The mood is positive. Theyre fine.
When you are outside the top four I dont think you should speak about title, when you are top four you can look up, see the distance, look to the fixtures, to the calendar, you can look to the situation at the moment, injuries, suspension and form.
Then you can feel it but in this moment we are outside top four so the point is now to get the points we need to try and be in the end of December in a better position than we are in now at this moment.