Recent short-range forecast guidance from global and regional models points to a daytime maximum in Istanbul near 20–22 °C on 18 May, reflecting a typical late-spring synoptic pattern with moderate southerly flow and limited cloud cover. This range aligns with the long-term climatological average high of 21 °C for mid-May, derived from decades of Turkish State Meteorological Service observations, while also allowing for modest day-to-day variability driven by sea-breeze effects from the Bosphorus and Black Sea. With model spread remaining narrow and no significant frontal passages expected, traders have concentrated probability on the 20–22 °C bins. Final resolution will hinge on the official 24-hour maximum recorded at the primary Istanbul station, with any late-afternoon convective development capable of trimming the peak by 1–2 °C.