X-ray magnetic circular dichroism (XMCD) is utilized to explore the temperature dependence of the interface moments in Co2 MnSi (CMS) thin films capped with aluminum. By increasing the thickness of the capping layer, we demonstrate enhanced interface sensitivity of the measurements. L 21 -ordered CMS films show no significant temperature dependence of either the Co or Mn interface moments. However, disordered CMS films show a decreased moment at low temperature possibly caused by increased Mn-Mn antiferromagnetic coupling. It is suggested that for ordered L 21 CMS films the temperature dependence of the tunneling magnetoresistance is not related to changes in the interface moments.