National Weather Service and ensemble model guidance for Houston on August 20 project a daily maximum near 98–99°F under mostly sunny skies and light southerly flow, anchoring the market’s leading 57% implied probability for that bin. Persistent late-summer heat-dome conditions across Southeast Texas, driven by strong high pressure and subsidence, suppress cloud cover and precipitation while enabling robust daytime heating; Gulf moisture maintains elevated heat indices but does not cap peak surface temperatures. Recent model runs show limited spread, mainly 97–101°F, consistent with August climatology centered in the mid-90s. Any unexpected afternoon convection or wind shift could trim the high by a degree or two, whereas stronger subsidence would favor the 100–101°F outcome at 17.5%. Traders heavily weight the near-term forecast consensus given proximity to resolution.