Modelling the accuracy and uncertainty of nodal demand contributes to matching the supply and demand of electricity and reducing energy waste and carbon emissions. Electricity demand is impacted by the national economic and social environment, which is innovatively quantified and applied to the forecasting system in this study. We take five regions in the UK and the neighbouring country Ireland as the case study. By experimenting with the deterministic and probabilistic scenarios at multiple horizons, we found that built external factors improved forecasts from 5% to 10%. The improvements vary due to the development of the economy and energy industry, and the level of Internet penetration in the region. Then, we identified the economic-beneficial regions as East Midlands and Northern Ireland, and the social-beneficial regions as West Midlands and South West. The influential social factors are military conflicts, transportation, the global pandemic, regional development, and the international energy market.