Recent National Weather Service and model guidance indicate the highest temperature in New York City on August 21 will likely fall in the upper 70s to low 80s, driven by a moderating air mass with light easterly flow, increasing afternoon cloud cover, and dew points in the upper 60s that limit full solar heating. Ensemble forecasts show only modest spread around the 79–82 °F range because steering patterns remain weak and no strong cold front or subsidence is expected to arrive before evening. These conditions align with the market’s tight clustering around 78–81 °F outcomes while leaving room for small adjustments if daytime mixing or timing of any sea-breeze effects differs from current runs. Historical August averages near 83 °F provide context, yet the near-term pattern favors slightly cooler readings. Updated model guidance tonight and early tomorrow will be the key data releases that could shift trader consensus before resolution.