The efficiency of the beekeeping industry largely depends on productive colony management, beehive location, climatic factors, and availability, richness, and proper utilization of the melliferous resources around the apiary. The present investigation identified the diversity of melliferous resources in the three selected study sites in the Second Congressional District in Cagayan Valley from March 2014 to April 2015 using a descriptive survey method of research. It likewise documented a bee floral calendar based on the pollen and nectar availability in the province. The study employed a frequency count in analyzing and discussing the gathered data. In the vegetations sampled, 54 plant species are useful to honeybees, 27 of which are forest trees, 25 are agricultural crops, and one each is a shrub and a weed. The study ascertained 18 flowering plants as extremely indispensable bee floras since these blossom throughout the year. March to May was the honey flow period in the study sites. July to September (dry season) and October to December (monsoon season) were the critical periods for honeybees. The floral calendar was developed in relation to the time and duration of bloom of the important honey and pollen plants. Northwestern Cagayan is suitable to sustain bee colonies.