Beijing experiences variable temperatures in mid-April as spring progresses toward warmer conditions. Daily highs typically range from 18°C to 24°C during this season, making a peak of exactly 21°C plausible but not the most likely outcome. Weather prediction markets on specific daily temperature readings require precise meteorological forecasts—in this case, whether the city's maximum temperature on April 20 will settle exactly at 21°C rather than above or below that threshold. The current 4% YES odds suggest traders assess this exact outcome as unlikely, reflecting the narrow band required for market resolution. Traders pricing the YES side this low are indicating that a peak temperature of 21°C is a relatively uncommon occurrence, even within the typical April range. Historical Beijing weather data and current meteorological forecasts shape these odds. The market closes at midnight UTC on April 20, after the day's full temperature cycle has been recorded. Because the resolution is binary—either the maximum temperature reaches 21°C or it does not—the odds directly reflect market consensus on this precise threshold.