Forecast models for Jeddah on July 15 show daily highs clustered near 36–38 °C, producing the tight market split among the 36 °C, 37 °C, and 38 °C+ buckets. Persistent subtropical high pressure supports strong solar heating, while Red Sea sea-surface temperatures above the 1991–2020 July baseline sustain elevated humidity that modulates peak readings through latent-heat effects and reduced nocturnal cooling. Light to moderate onshore flow and sea-breeze timing introduce day-to-day variability of 1–2 °C, and ensemble spread in global and regional models reflects lingering uncertainty over exact ridge strength and boundary-layer moisture. Recent mid-July observations around 35–37 °C reinforce the narrow range, with new model runs and official updates from Saudi meteorological sources expected to refine the outcome before resolution.