Recent National Weather Service forecasts and ensemble runs from the GFS and ECMWF models project Houston highs in the mid-to-upper 80s on May 17 under mostly sunny skies and light southerly flow, enabling strong daytime heating with minimal cloud interference. This setup matches mid-May climatology, where the 1991-2020 normal high at Houston Intercontinental Airport is 87°F, and follows a week-long warming trend driven by a strengthening upper-level ridge promoting subsidence. The market’s 90.5% implied probability for 86°F or higher reflects this consensus, tempered by the possibility of isolated afternoon convection that could briefly limit peaks but is unlikely to drop readings below the threshold based on current guidance. Official observations at resolution time remain the decisive factor.