**Persistent extreme heat and mostly clear skies under a strong high-pressure system are keeping overnight lows elevated across North Texas, with National Weather Service forecasts calling for a minimum around 82°F on August 21.** This aligns with the closely bunched market-implied odds clustered between the 80–81°F, 82–83°F, 84–85°F, and 86–87°F bins, reflecting trader uncertainty over exact cooling rates. Key scientific drivers include above-normal temperatures (10–15°F warmer than August averages), high dew points near 62°F that limit radiative cooling, light southerly winds reducing mixing, and the Dallas urban heat island effect that traps warmth. An Extreme Heat Warning remains in effect, with models showing minimal disagreement on the lack of clouds, precipitation, or a cold front that could otherwise drop readings into the upper 70s. Minor variations in forecast guidance on wind speed or boundary-layer moisture explain the tight spread among leading outcomes, as traders weigh these subtle factors against historical late-August minima typically near 75–77°F.