The combination of high-throughput experimentation and software for comprehensive data capture enables a strategy of data-driven automated serendipity. We previously described our Robot-Accelerated Perovskite Investigation and Discovery (RAPID) system for synthesis of lead iodide perovskites by ITC. Reactions are performed in batches of 96 experiments, typically sampled randomly over the achievable composition space. For the present analysis, reaction outcomes are reduced to a binary score (does a crystal form or not), independent of size or quality. Figure depicts the observed crystallization probability in 94 batches containing 8,470 reactions collected over 20 months in a single laboratory. (A full copy of this dataset, `perovskite0057` and the corresponding data analysis code are provided in the Supplementary Materials.) Our Experiment Specification, Capture, And Lab Automation TEchnology (ESCALATE) software captures not only the experiment specification (composition, temperature, and other processing conditions) and reaction outcome, but also metadata associated with the experiment. This metadata includes ambient laboratory conditions, including laboratory humidity. As reactions are performed in open atmosphere (not in a glove box), they experience variations in laboratory humidity. The distribution of observed relative humidity (% RH) is shown in Figure .