Trader consensus on Polymarket has locked in a 100% implied probability for a lowest temperature of 50-51°F in New York City on April 28, driven by finalized observations from the LaGuardia Airport station—the market's resolution source via Wunderground data—which recorded the minimum in that precise range. Mild southerly flow and urban heat retention under partly cloudy skies overnight prevented sharper cooling, aligning with National Weather Service model consensus from the prior day forecasting lows near 50°F amid a broader warm spring pattern. Late April climatology supports this, with historical Central Park analogs averaging 48°F lows. Realistic challenges are minimal post-finalization, though rare data audits could prompt revisions; otherwise, resolution appears certain.