Trader consensus on Polymarket prices a 40% implied probability for San Francisco's highest temperature on April 12 falling in the 58-59°F range, closely followed by 56-57°F at 26% and 60-61°F at 23.5%, reflecting National Weather Service guidance and NOAA model ensembles showing persistent marine stratus clouds capping daytime heating amid cool onshore winds and Pacific sea surface temperatures near 55°F. Recent developments include below-normal highs over the past 48 hours—such as 55°F on April 9 at San Francisco International Airport—with slow stratus burn-off due to typical springtime low-level marine inversion layers. ENSO-neutral conditions through April reinforce climatological norms, where April averages 62°F but fog often suppresses peaks. New hourly NWS updates and afternoon observations will clarify if solar penetration allows a push toward 60°F.