Cohort splitting has been described as differences in time until maturation and / or life span in the same age group. Cohort splitting generally occurs when individuals of a cohort originating from the same season experience different environmental conditions, such as in early and late progenies. However, in the wolf spider Pardosa agrestis (Westring, 1861) spiderlings of the same clutch may follow either slow or rapid development, leading to a second adult peak within a year comprised of the rapidly developing individuals. We hypothesized that weather conditions experienced by the spiderlings in their early ontogeny may contribute to a life history decision between slow and rapid development. To test this hypothesis, we have used long term collection data and non-parametric habitat modeling. We found that highest abundance of the rapidly developing phenotype was correlated with a narrow range of early weather conditions. This result is in accordance with our early choice hypothesis, although the possibility remains that differential survival of the developmental morphs also contributes to the observed pattern.