The global effort towards decarbonising the transportation sector has intensified interests in hydrogen-based solutions, particularly in energy-intensive applications such as heavy goods vehicles (HGVs), where battery technologies may be limited. This study investigates the seasonal dynamics of green hydrogen supply powered by an offshore wind farm (OWF) and the demand of Portsmouth City freights, focusing on the year 2050. Using Geographic Information System (GIS) tools, locations for OWF and green hydrogen production facilities are identified by analysing offshore wind resource areas, proximity to transport routes, demand centres, and potential storage hub. Geospatial analysis was done using ArcGIS and Global Wind Atlas tools, while seasonal hydrogen production and demand are simulated using MATLAB. The results reveal a notable seasonal mismatch between hydrogen demand for logistics and road freight, and the supply of hydrogen generated by electrolysers. The seasonal mismatch in green hydrogen production and demand are used to propose a dynamic pricing model that incentivises hydrogen consumption during surplus periods while mitigating supply deficits. This work is important as it provides the foundation to investigate demand side management under freight transport.