Abstract The simulation of the onset of the West African monsoon (WAM), associated with the northward shift of the Intertropical Convergence Zone (ITCZ) occurring in May, June, and July, is a challenging task for atmospheric general circulation models (AGCMs), because of complex water and energy balance through the land‐atmosphere interaction as well as atmospheric processes. We provide evidence that a combination of state‐of‐the‐art global fields of reanalyzed soil moisture anomalies and a sufficiently high‐resolution (∼50 km) AGCM produces a successful simulation of the northward shift of the ITCZ and the following onset of the WAM in July. Copyright © 2011 Royal Meteorological Society