This market will resolve based on the highest temperature recorded in the 'Daily Observations' table on Weather Underground, not the figure displayed in the 'Day High & Low' summary section; in the event of any discrepancy between the two, the Daily Observations table shall be the primary resolution source not the Day High & Low section. This market will resolve to the temperature range that contains the highest temperature recorded at the London City Airport Station in degrees Celsius on 16 Aug '26. The resolution source for this market will be information from Wunderground, specifically the highest temperature recorded for all times on this day for the London City Airport Station, available here: https://www.wunderground.com/history/daily/gb/london/EGLC. To toggle between Fahrenheit and Celsius, click the gear icon next to the search bar and switch the Temperature setting between °F and °C. This market can not resolve until the first data point for the following date has been published on the resolution source. The resolution source for this market measures temperatures to whole degrees Celsius (eg, 9°C). Thus, this is the level of precision that will be used when resolving the market. Revisions to temperatures recorded within this market's timeframe will be considered until the first datapoint for the following date has been published, after which any alterations will not be considered.
Met Office guidance currently centers on a 26°C maximum for London on August 16, 2026, aligning with the market’s leading 26°C outcome at 29.5% implied probability. Ensemble forecasts show tight clustering around 25–27°C because a weakening high-pressure ridge is giving way to fresher Atlantic airflow, moderating temperatures after the recent heatwave. Key variables include the exact timing and coverage of any showers or increased cloud that could cap afternoon heating, versus clearer spells allowing stronger insolation. Wind direction and boundary-layer mixing also influence whether peak readings occur at official stations. With only 48 hours until resolution, traders are weighting the latest model runs and official briefings that place the most probable range between 25–27°C, while assigning lower odds to extremes outside that band due to limited remaining uncertainty in the forecast evolution.