Linear speed in circular motion depends on angular velocity (here: 1 rotation per day, for all latitudes) and radius of the circle - distance from the axis of rotation.

$ v = \omega r$

[![enter image description here][1]][1]

If $\alpha$ is your latitude, the radius of the circle you make with each revolution of Earth, is $r$. As you can see above, basic trigonometry, ${r \over R} = cos \alpha$. The closer you are to the pole, the more each degree of latitude decreases the radius of the circle you make.

Indirect consequence is that moderate distance of the space center from the equator diminishes delta-V much less than larger distance. 

Take:

French Guiana Space Centre is 5 degrees North; Cape Canaveral is 28 degrees North; Baikonur is 45 degrees North, Plesetsk is 63 degrees North.

It would superficially seem that the velocity losses between Guiana and Canaveral (23° apart) are higher than between Canaveral and Baikonur (17°) or Baikonur and Plesetsk (18°). But this is not the case - 

$\cos 5° - \cos 28° =  0.11;$ 

$ \cos 28° - \cos 45°  = 0.17;$ 

$ \cos 45° - \cos 63° = 0.25 $

so the 17 degrees Baikonur loses to Canaveral is way worse than 23
 degrees Canaveral loses to Guiana or the 58 degrees Baikonur loses to Guiana.

  [1]: https://i.sstatic.net/XiyIp.png