According to the European Wind Energy Association (EWEA), more than 1.000 offshore wind turbines will be installed within the next ten years from now. Regarding these studies, the prospective transport vessel capacity will be the bottleneck of offshore wind parks installations. Furthermore, first experiences from offshore wind park installations have shown that adverse weather often delays or even completely stops installation processes. Only certain installation processes such as setting groundings are feasible in bad weather, yet others for example the assembly of blades and nacelles require a calm conditions. Our approach is to schedule the offshore installation processes considering seasonal and up-to-date weather forecasts based on a heuristic algorithm. To determine the quality of this heuristic, we previously developed a mathematical model (Mixed Integer Linear Programming -MILP) to calculate the optimal installation schedule. This was done by including different weather conditions, installation processes and sets for vessel loadings. Since the mathematical problem is NP-hard, the MILP is only applicable for small installation scenarios. However, our heuristic is able to consider longer time horizons, multiple vessels and a broader variety of weather conditions. We simulate different weather conditions and compare our heuristic to the results of our MILP using a case study.