London's weather in mid-April typically ranges between 8 and 15 degrees Celsius, making a high of exactly 9°C a narrow but plausible outcome during cooler spring spells. This prediction market tracks whether the highest temperature recorded in London on April 20 will be precisely 9°C, based on official meteorological data from the UK Met Office. Currently trading at 0% YES odds, this outcome is priced as extremely unlikely by market participants, who expect either warmer conditions driven by lengthening April daylight, or a temperature that misses this specific mark by a degree or more. The specificity of 9°C reflects London's spring transition period, where cold Atlantic fronts can occasionally push temperatures down into single digits, but sustained warmth from increased daylight typically drives highs into the 12-15°C range. The 0% odds suggest high market confidence that temperatures will exceed 9°C on this date. This one-day market resolves at midnight UTC on April 20 using transparent, easily verifiable official meteorological records. Such precise temperature predictions appeal to weather enthusiasts and those seeking markets on specific meteorological outcomes rather than broader seasonal trends.