ABSTRACT. Hawaiian dryland agriculture is believed to have played an important role in the rise of archaic states and consolidation of political power. At the same time, the sensitivity of agricultural production in dryland field systems to temporal variability in climate would have had implications for economic and political relationships, both competitive and cooperative. In this study, we explore whether and how annual cycles of climate might have constrained seasonal cultivation and crop production in three rain-fed field systems on the Island of Hawaiʻi. We utilized a recently developed monthly gridded climate dataset for the Hawaiian Islands to compare the Kohala, Kona, and Kaʻū field systems in terms of mean annual climate and seasonality. We found that despite superficial similarities in elevation and annual rainfall, the field systems differ in climatic variables associated with evaporative water loss and in the timing of the rainy season. Aridity, a ratio of evaporative demand to rainfall, is strongly seasonal for Kohala and Kaʻū relative to Kona. When we imposed temperature and moisture criteria to visualize seasonal cultivation envelopes defined for sweet potato (Ipomea batatas), we found strong spatial patterns associated with the onset and length of the growing season, and these suggest seasonal complementarity in crop production within and between field systems. This complementarity indicates coordination both within and between field systems through consolidation, coercion, or increased cooperation could have alleviated periodic food stress and contributed to more stable political hierarchies, which may explain similarities in their respective chronologies of development. We suggest that our approach for characterizing seasonal constraints to dryland cultivation provides a useful tool for advancing continued restoration and research in these and other rain-fed dryland systems across Hawaiʻi and the tropics.