Seasonal climate variability frequently undermines farm yields, reduces food availability, and lowers income. This is particularly evident among small-scale agricultural producers in both irrigated and non-irrigated agroecosystems in the Global South where maize cultivars constitute a critical component of food production. In these systems, farmers make climate-sensitive decisions that include the selection of late- and/or early-maturing seed varieties, the diversity of seed varieties sown, and when to plant. Farmers’ expectations of future rainfall would therefore seem to be critical determinants of agricultural outcomes and foreshadow climate impacts. However, few studies have quantified the linkages between on-farm decisions and farmer seasonal predictions. We report on detailed household and phone surveys of 501 smallholder farmers in central Kenya based on the 2018 growing seasons and expectations for the 2019 March-April-May growing season. We show that farmers’ expectations of the upcoming seasonal rainfall have important associations with selections of seed maturity varieties and the number of maturing varieties farmers expect to plant and less important associations with the seeds’ planting dates. Furthermore, we show that 79% of the farmers form an expectation of the future seasonal climate and about two-thirds of them formed expectations based on a heuristic that connects the past climate to future seasonal conditions. More problematically, one-third of the farmers formed their rainfall expectation based on the prior season, and we show that no such correlation exists in observational data nor is correlation of seasonal rainfall supported by current understanding of climate variability. These results highlight the challenges farmers face in anticipating seasonal rainfall, which has implications for crop diversification and choices to adopt drought tolerant cultivars. The results suggest that farmers’ expectations of upcoming seasonal climate are important measures of farm decision-making.

季节性气候变化经常破坏农业产量，减少粮食供应，并降低收入。这在全球南部的灌溉和非灌溉农业生态系统中的小型农业生产者中尤为明显，在这些国家中，玉米品种是粮食生产的重要组成部分。在这些系统中，农民做出对气候敏感的决定，包括选择晚熟和/或早熟种子品种，播种种子品种的多样性以及何时播种。因此，农民对未来降雨的期望似乎是决定农业产量和预示气候影响的关键因素。但是，很少有研究量化农场决策与农民季节性预测之间的联系。我们报告了肯尼亚中部501位小农户的详细家庭和电话调查，这些调查基于2018年的生长季节以及对2019年3月至4月至5月的生长季节的预期。我们表明，农民对即将到来的季节性降雨的期望与种子成熟度品种的选择和农民期望种植的成熟品种的数量具有重要关联，而与种子播种日期的关联则不那么重要。此外，我们表明，有79％的农民对未来的季节性气候有期望，而大约三分之二的农民是根据将过去的气候与未来的季节性条件联系起来的启发式的。更成问题的是，三分之一的农民根据上一个季节形成了他们的降雨预期，而且我们发现，观测数据中不存在这种相关性，当前对气候变异性的了解也无法支持季节性降雨的相关性。这些结果凸显了农民在预期季节性降雨时将面临的挑战，这对作物多样化和采用耐旱品种的选择产生了影响。结果表明，农民对即将到来的季节性气候的期望是农业决策的重要指标。