The farming communities living in the Lower Bengal Delta, Bangladesh are vulnerable to hydroclimatic variability. Farming decisions are becoming risky due to unpredictable weather patterns. The southwest region of Bangladesh, located in the heart of the Lower Bengal Delta, is known as an ecologically rich and productive agriculture zone. At the same time, smallholder farming communities are confronted with recurrent hydroclimatic events such as cyclones, storm surges, tidal flooding, and salinity intrusion among others. These events severely affect the agricultural income, livelihood, and food security of farming communities. Improved management of these hydroclimate risks is necessary to improve the livelihood and food security of the smallholders. Hydroclimate information services and technology hold the potential to help smallholders to manage hydroclimatic risks through informed agricultural decision-making. However, there is a scientific challenge for developing services and bridges between the available model-based forecasts and the local context and capabilities. The central question is how hydroclimatic information services can be tailored in ways that local farmers find useful in decision-making processes for their crops and livelihood activities. Another transdisciplinary challenge is balancing information service providers and end-users, integrating social science and climate science perspectives. Understanding end-user needs and capacity, local knowledge institutions, and policy are also fundamental challenges for the co-production of services for sectoral end-users and improving the value of forecasts information. There is a need for timely, accurate, and effective hydroclimatic information services mechanisms. The existing information services are largely developed from a top-down perspective. A bottom-up approach, shaped by users' requirements, engagement and capacity building has not been attempted yet. In this dissertation, I aim to co-produce hydroclimatic information services with smallholder farmers in the lower Bengal Delta in Khulna, Bangladesh. A mixed-methods transdisciplinary research approach was applied to study current knowledge gaps that exist regarding (i) farmers' practices and the role of available information, (ii) hydroclimatic information needs of smallholders, (iii) co-production of information services with and for smallholder farmers, and (iv) willingness to pay for location-and time-specific climate information services for wider uptake, improved agricultural practices, and service sustainability. This study confirms that there is a potential for need-based tailored information services for smallholders. However, farmers' information needs assessment is not a single-step process. This requires iterative interaction and capacity building. The coproduction study shows that hydroclimate information services through actors' collaboration, capacity building of farmers, and extension officers at farmer field school lead to better understanding, accessibility, and uptake of weather...