San Francisco's weather on April 18, 2026 will be measured against official National Weather Service records. This market focuses on whether the day's high temperature will fall within the narrow 60-61°F range. The current 0% YES odds reflect market participants' view that this specific temperature band is highly unlikely. San Francisco's typical April conditions range from mid-50s to low-70s Fahrenheit, so the 60-61°F prediction represents a cooler-than-average scenario. Market prices embed expectations based on seasonal patterns, extended weather forecasts, and historical volatility. The tight band width means small deviations in either direction—even just one degree—will cause the market to resolve NO. Traders use weather prediction markets for multiple purposes: to hedge temperature-dependent business risks, to test forecast accuracy against commercial weather models, or to express conviction about seasonal patterns. Market resolution occurs at the close of April 18, 2026, based on official high temperature data from San Francisco International Airport (SFO) or NOAA surface stations monitoring the Bay Area. Winners receive payment based on their position size and entry price.