Latest ensemble forecasts from agencies like the Japan Meteorological Agency indicate Tokyo's maximum temperature on July 29 will likely fall in the 32–34°C range, driving the closely bunched market probabilities around 31–33°C. Variability stems from uncertainty in the strength and position of the North Pacific subtropical high, which controls southerly flow and urban heat retention, alongside potential weak frontal influences or cloud cover that could moderate peaks. Historical July climatology shows typical maxima near 31°C with a standard deviation of 2–3°C, underscoring why small shifts in model guidance or observational updates can reweight outcomes. Traders are monitoring the next model cycles for clearer signals on these steering patterns ahead of resolution.