Effectiveness of weather and climate information is fundamentally critical to agricultural decision making. Well informed farm-level decisions are significant in impacting crop yields, improving food security, and the overall livelihoods of smallholder farmers. Using an explanatory sequential mixed-method strategy involving 412 respondents and 23 participants, this study examines the effectiveness of weather and climate information (WCI) channels available to smallholder farmers in northern Ghana. Mean ratings were used for measuring the effectiveness of the channels while frequency distribution and contingency table analyses were used to analyse the timeliness of WCI. The quantitative results were accompanied by qualitative analysis of responses using key informant interviews. For smallholder farmers, radio appeared to be the most effective channel even though information from Agricultural Extension Agents and NGOs were more trustworthy and effective in providing feedback. The results also indicate an under-utilisation of digital-related platforms in information dissemination despite its ability to provide real-time information. Results from the Friedman rank test revealed a statistically significant difference in trust rankings across the communication channels, χ² (11) = 2265.61, p < 0.001 indicating that respondents differed in the assignment of ranks to the various channels. Results of the key informant interviews supported the results of the quantitative findings. Therefore, strengthening radio programmes for disseminating effective WCI is ideal. Hybrid dissemination channels and channel-to-audience segregation linking the needs of farmers to specific channels should be promoted. This will ensure channel effectiveness in providing timely and trusted weather information to enable smallholder farmers make informed choices.