San Francisco's April weather typically varies between 50–65°F depending on wind patterns and marine layer influence. This market tracks whether the city's highest temperature on April 18 will fall within the specific 56–57°F range, a narrow band that requires precise atmospheric conditions. Current market odds of 0% suggest traders expect the high to fall outside this range—either cooler due to persistent fog or warmer from inland heating. Weather data from the National Weather Service is public and easily verifiable, making this market fully resolvable at market close on April 18. Similar daily temperature markets have shown that very narrow ranges (one-degree windows) typically attract lower odds than broader bands, which aligns with the current 0% sentiment. The 24-hour volume of $611 and liquidity of $11,239 reflect the niche appeal of hyperspecific weather predictions, though such markets attract weather enthusiasts and local forecasting hobbyists interested in granular climate tracking.