The US Department of Agriculture's Summer Food Service Program and Seamless Summer Option (summer nutrition programmes (SNP)) aim to relieve food insecurity for children and teens during summer months. More needs to be known about when and where SNP are available, and how availability varies by community characteristics, particularly in rural areas where food insecurity and reduced food access are more prevalent.The present study examined the geographic availability of SNP and summer meal uptake rates in 2016, using state-wide administrative claims data.Public schools and SNP in California, USA.ParticipantsSchools (n 8842) and SNP (n 4685).Urban counties were more likely than rural counties to have higher summer uptake rates, calculated as the percentage of summer meals served relative to eligible students utilizing school meal programmes during the academic school year, but uptake overall was low at 18·2 % of target populations. Geographic availability analyses showed that 63·9 % of public urban schools had an SNP available within 1·6 km (1 mile), but availability was significantly higher within the proximity of larger, higher-poverty high schools with diverse or majority non-White students, and those with higher school-year breakfast participation rates. Availability of an SNP within 16 km (10 miles) of rural schools averaged 68·1 % but was significantly higher around larger schools, higher-poverty schools and those with diverse or majority non-White students.While many communities have SNP available, much more work is needed to increase the availability of these programmes to reduce summer food insecurity for children, particularly in rural communities.