What month are yellowjackets most aggressive?

What month are yellowjackets most aggressive? Yellowjackets are most aggressive in late summer to early fall, specifically August and September, with peak aggression in August and September, sometimes extending into October depending on climate. During this time, colonies have reached maximum size, with many workers, and their natural food sources decline, making them more likely to forage aggressively around human food, sweets, and garbage, and defend nest vigorously. In spring and early summer, colonies are small and less aggressive. By late summer, workers are more irritable, and with queen no longer producing as much, they seek sugars. In fall, as temperatures drop, they become more desperate for food. So August and September are months when yellow jackets are most aggressive and most likely to sting, as they are more numerous and more attracted to human activities outdoors like picnics and barbecues.