Higher outdoor temperatures are associated with greater incidence of firearm violence in urban areas in the United States. This study adds to the existing literature base by exploring the potential mitigating role of air conditioning (AC). The setting for this repeated-measures ecological cross-sectional study is New York City Housing Authority (NYCHA) developments, which are known to experience disproportionate rates of firearm violence. We extracted data for 2012–2017 for two types of shooting events: all New York City (NYC) shootings and those in NYCHA housing. Negative binomial mixed-effects regressions explored the relationship between electricity consumption, a proxy for AC use in warmer months, and shootings, controlling for housing development characteristics and the Area Deprivation Index. Separate analyses were conducted for months whose maximum average temperatures were in different deciles. During our study period, 18% of NYC shootings occurred in NYCHA housing. We observed a positive relationship between monthly maximum temperature decile and NYCHA shooting incidence (IRR = 1.11, 95% CI: 1.08, 1.14). For months with temperatures in the top decile (84–87°F), increased electricity consumption was associated with a decrease in the expected rate of shootings (IRR = 0.79, 95% CI: 0.63, 0.98). These findings suggest AC and other cooling-related interventions may be useful in reducing firearm violence in public housing during hotter months. However, improved data on AC access and use are needed to better understand this relationship.