On 2021-07-21 the Air Quality Index in New York City was 175, rated unhealthy, due to haze from West Coast fires.

Judge for 2021-07-21. True: the official AQI reading for New York City (EPA AirNow or NYS DEC) on that day reached about 175 (roughly 160–190), in the 'Unhealthy' category (151–200), and agencies or news attributed the haze to smoke from western US/Canadian wildfires. Mostly true: AQI was in the Unhealthy range but the peak figure differed somewhat from 175 (for example 151–159 or 191–200), or the smoke came from western Canada as well as the West Coast. Mixed: AQI was in the 'Unhealthy for Sensitive Groups' range (101–150) with wildfire smoke confirmed. Mostly false: AQI was only Moderate, though wildfire haze was present. False: there was no notable wildfire-smoke air quality event in NYC that day.

Set before the research began.

1. E1 New Yorkers: It Might Be Time to Get Yourself an Air-Quality App Curbed · 20 July 2021

   “On the air-quality index, the Environmental Protection Agency’s method of reporting airborne pollutants, parts of Manhattan are currently reporting numbers upwards of 175, putting them in the red “unhealthy” zone.”

2. E2 Western wildfire smoke is contributing to New York City’s worst air quality in 15 years | CNN CNN · 21 July 2021

   “The city had a 24-hour average Air Quality Index of 154 on Tuesday, the worst it’s been since June 2006, when the AQI was 157.”

3. E3 Western wildfire smoke is contributing to New York City’s worst air quality in 15 years | CNN CNN · 21 July 2021

   “Smoke stretched early Wednesday all the way to the East Coast, including New York City, because high-level winds carried them thousands of miles from the West.”

Curbed (E1), dated 2021-07-20, reported AQI readings "upwards of 175" in parts of Manhattan, in the red "unhealthy" zone. CNN (E2) reported a 24-hour average NYC AQI of 154 for Tuesday, July 20, which falls in the Unhealthy range and was the worst since 2006. CNN (E3) also confirmed that western wildfire smoke was still over New York City on Wednesday, July 21. The ~175 figure, the "unhealthy" rating and the western-wildfire cause are all independently supported, but no evidence states an AQI figure for July 21 itself, and E1 does not name an official station or data source, so the verdict is mostly true rather than true.