Air quality alerts are issued when pollution levels rise to unhealthy levels, warning the public, especially vulnerable groups, to limit outdoor exposure for health and safety.

Another air quality alert is in effect Tuesday for NYC, western Long Island, the Hudson Valley, northwest New Jersey and southwest Connecticut.

Hazy skies descend over the New York City area again on Tuesday, re-upping some air quality alerts related to Canadian wildfire smoke. As of 10 a.m., the air quality index was 121, which is considered unhealthy for sensitive groups.