Trader consensus on Polymarket closely splits between 50-51°F (31.5%) and 52-53°F (30.5%) for New York City's highest temperature on April 20, driven by the latest National Weather Service forecasts and GFS/ECMWF ensemble means projecting daytime highs near 51°F under persistent cool northerly winds and lingering low-level clouds from a recent frontal passage. This setup features shallow boundary layer mixing limiting surface warming, with climatological April 20 normals around 59°F suppressed by unfavorable upper-air patterns akin to recent cool anomalies. Differentiating the tight outcomes are model sensitivities to afternoon clearing—earlier sunshine could nudge peaks toward 53°F, while prolonged overcast favors 50°F—highlighting springtime forecast uncertainty at 48 hours out. Watch for 00Z model runs and NWS updates Sunday for refinements ahead of resolution via Central Park observations.