Figure shows the temperature distribution for the pallet at three points in time, selected based on the fraction of nucleated vials, for a storage temperature of -40°C; figures 18 and 19 in the supplementary information showcase the process at storage temperatures of -20°C and -8°C. We notice both a layer-wise progression of freezing at low storage temperatures and a stationary temperature for vials in the core, whereby the spatial extent of this stationary region shrinks with time. Furthermore, we identify individual vials at higher temperatures than their neighbors -they correspond to vials that just solidify at the corresponding point in time. The pronounced position-dependency of freezing necessitates a more detailed investigation based on the characteristic quantities. To do so, we define position-dependent populations of vials with different distance to the side of the pallet. The simulated pallet comprises 18 vertical layers, which may be categorized into nine populations based on their location along the vertical axis. The outermost population, referred to as layer 1, comprises vials in the top-most and bottom-most layers, which exhibit the same thermal environment. To exclude edge and corner effects (which are studied in detail in section 5.5 in the supplementary information), only the 36 vials in the center of each layer are included in the populations. The relevant subset of vials is contained in a rectangle, as visualized for layers 1, 5 and 9 in the left column of Figure . Figure (a) illustrates the distribution of nucleation times for the three studied layers. As anticipated, vials nucleated earlier, the closer they were to the exterior. For high storage temperatures, i.e. in the nucleation-limited regime, the nucleation times for the individual positions strongly overlap with each other, indicating that at any given time vials in several layers are nucleating and solidifying. Under colder conditions, less overlap was observed, indicating a layer-wise freezing process from the outside to the core. Independent of storage temperature, the innermost layer 9 exhibited the broadest distribution of nucleation times. We attribute this behavior to the formation of the stationary phase, which comprises most of the process duration, and during which nucleation events may occur. While the reduced position-dependency of nucleation times at higher storage temperature may be beneficial in terms of product quality control, the long process duration at such storage temperature may lead to such operating conditions being infeasible in practice.