Many years ago I worked an armed security position guarding the home renovation project in Cherry Hill. We always hoped for cold or rain to keep people off the streets. With summer approaching the murder rate is likely to rise with the temperatures .
Air conditioning lowers the threat of unrest significantly as well.
Want a prime threat scenarion for a terrorist attack? Wait for a heat wave, with hot and sunny days projected for 5 days to a week out. Then target electrical infrastructure.