On October 29, 2012, Hurricane Sandy made landfall in New Jersey, causing major power outages, flooded roads, and disruption of public transportation. Individuals diagnosed with diabetes may be especially vulnerable to natural disasters because of limited access to medications or use of glucose monitoring devices. We examined changes in emergency room visits (ERVs) for type II diabetes mellitus potentially associated with Hurricane Sandy in New Jersey. Data analyzed in 2014 included ERVs to general acute care hospitals in New Jersey among residents of three counties with a primary or secondary type II diabetes diagnosis (PDD or SDD) in 2011–2012. Compared to the previous year, results showed an 84% increased rate of PDD ERVs during the week of Hurricane Sandy, after adjusting for age and sex (rate ratio (RR) = 1.84, 95% confidence interval (CI) 1.12, 3.04). Results were nonsignificant for SDD (RR = 0.94, 95% CI 0.83, 1.08). Spatial analysis showed the increase in visits was not consistently associated with flood zone areas. We observed substantial increases in ERVs for primary type II diabetes diagnoses associated with Hurricane Sandy in New Jersey. Future public health preparedness efforts during storms should include planning for the healthcare needs of populations living with diabetes.