Rice farmers in Northern Ghana are susceptible to climate variability and change with its effects in the form of drought, water scarcity, erratic rainfall and high temperatures. In response, farmers resort to weather and seasonal forecast to manage uncertainties in decision-making. However, there is limited empirical research on how forecast lead time and probabilities influence farmer decision-making. In this study, we posed the overall question: how do rice farmers respond to forecast information with different probabilities and lead times? We purposively engaged 36 rice farmers (12 rainfed, 12 irrigated and 12 practising both) in Visually Facilitated Scenario Mapping Workshops (VFSMW) to explore how probabilities and lead times inform their decision-making. Results of the VFSMW showed rainfed rice farmers are most sensitive to forecast probabilities because of their over-reliance on rainfall. Also, an increase in forecast probability does not necessarily mean farmers will act. The decision to act based on forecast probability is dependent on the stage of the farming cycle. Also, seasonal forecast information provided at a 1 month lead time significantly informed farmer decision-making compared to a lead time of 2 or 3 months. Also, weather forecast provided at a lead time of 1 week is more useful for decision-making than at a 3 day or 1 day lead time. We conclude that communicating forecast information with their probabilities and at an appropriate lead time has the potential to help farmers manage risks and improve decision-making. We propose that climate services in Northern Ghana should aim at communicating weather and seasonal climate forecast information at 1 week and 1month lead times respectively. Farmers should also adapt their decisions to the timing and probabilities of the forecast provided.

加纳北部的稻农易受气候变化和气候变化的影响，其影响形式包括干旱，水资源短缺，降雨不稳定和高温。作为响应，农民诉诸于天气和季节预报来管理决策中的不确定性。但是，关于预测提前期和概率如何影响农民决策的经验研究有限。在这项研究中，我们提出了一个总体问题：稻农如何响应具有不同概率和交货时间的预报信息？我们有目的地邀请了36名稻农（12名接受雨水灌溉，12名灌溉人员和12名农民同时参加）在视觉便利的方案制图研讨会（VFSMW）中探讨了概率和交货时间如何影响他们的决策。VFSMW的结果表明，雨养稻农对预报概率最为敏感，因为他们过度依赖降雨。同样，预测概率的增加并不一定意味着农民会采取行动。根据预测概率采取行动的决定取决于耕种周期的阶段。此外，与2个月或3个月的提前期相比，提前1个月的提前期提供的季节性预报信息可以极大地指导农民的决策。此外，提前1周的天气预报提供的决策比提前3天或1天的天气预报更有用。我们得出的结论是，在适当的交货时间传达预报信息及其概率的潜力有可能帮助农民管理风险并改善决策。我们建议加纳北部的气候服务的目标应是分别在1周和1个月的提前期传达天气和季节性气候预报信息。农民还应根据提供的预报的时机和概率调整其决策。