The 2016 American Northeast heat wave was a heat wave which affected New York, New Jersey, and Pennsylvania with heat indexes reaching up to 45 °C (113 °F).
Meteorological history
A ridge of high pressure aloft began to slowly build as it began to move into the Northeast during the mid-week of August 8–12. Southerly winds from the Southwest transported moisture to the ridge, which increased the humidity levels in the atmosphere. With this, high temperatures in the cities such as Washington D.C, New York City and Philadelphia were expected to climb to 32–38 °C (90–100 °F), with heat indexes as high as possibly 42 °C (108 °F). making it extremely hot and muggy. Excessive heat warnings and watches were posted for the afflicted cities.
The heat wave lasted into the middle of the following week, before temperatures cooled down slightly to August-average.