These three prediction markets aggregate collective expectations around London's highest temperature on May 17, 2026. Weather prediction is inherently uncertain—meteorological models diverge, and atmospheric conditions can shift unexpectedly even days before an event. Prediction markets offer a real-time snapshot of how informed participants assess the probability of specific temperature outcomes. The three markets here cover distinct temperature scenarios: outcomes at exactly 11°C, exactly 12°C, and temperatures reaching 20°C or higher. Together, they form a ladder of expectations across the temperature spectrum. When you examine the prices (displayed as probabilities from 0 to 100%), you're seeing a collective assessment of what London's weather is most likely to deliver. A market trading at 45¢ indicates roughly a 45% chance of that outcome occurring; markets with higher prices reflect outcomes the crowd views as more probable. What's valuable here is the spread: comparing how the market prices different temperature points reveals where participants see the most uncertainty. If the 11°C and 12°C markets both trade low while the 20°C-or-higher market trades high, you're seeing the market's conviction that London will experience notably warm conditions. Conversely, if mid-range temperatures command higher prices, it suggests participants expect moderate conditions with wider uncertainty bands. These markets update continuously as new forecasting data arrives, major weather systems develop, or as traders adjust their views. By May 17, one of these outcomes will resolve to yes and the others to no, revealing which prediction the market assessed most accurately. For anyone interested in weather, climate patterns, or how groups with real financial stakes assess probabilistic events, these markets provide both a data source and a lesson in collective decision-making under uncertainty.