**Recent Met Office guidance and ensemble forecasts position London's maximum temperature on August 4, 2026, near 28°C, with a narrow range of 27–29°C reflecting modest uncertainty in timing and cloud cover.** High pressure building across southern England has allowed warmer air advection from the continent, supporting daytime highs in the upper 20s after a brief cooler, more changeable spell earlier in the week. Model consensus shows south-east England reaching 28°C under mostly sunny conditions, though scattered showers or increased cloud from an approaching Atlantic front could cap the peak closer to 27°C. Conversely, stronger insolation or delayed frontal passage could push readings to 29°C, especially in central London where the urban heat island effect adds 1–2°C relative to rural sites. Climatologically, early August maxima average 22–23°C, so current conditions represent above-normal warmth driven by the subtropical ridge. Resolution hinges on official Met Office observations, typically the highest 1-minute reading at a designated London station. Trader sentiment clusters around 27–29°C because ensemble spreads remain tight within this band, with lower probabilities assigned to 30°C+ only if the warm plume strengthens further or to sub-27°C if showers arrive earlier than expected. Updated model runs and the next Met Office briefing will likely refine these odds as the event draws nearer.