**Trader sentiment for the lowest temperature in Panama City on September 4 reflects tight uncertainty around typical tropical nighttime values near 24–26 °C, driven by an active tropical wave and persistent high humidity.** Current official and model guidance (including GFS and local IMHPA outlooks) points to overnight lows of roughly 24–26 °C (75–79 °F) under partly cloudy to thundery conditions, consistent with September climatology of ~24 °C average minima. The closely matched probabilities—led by 26 °C at 49 % and 19 °C or below at 48 %, with 29 °C or higher near 47.5 %—highlight genuine forecast spread rather than a strong directional bias. Key differentiating factors include the passage of onda tropical #42, which is sustaining atmospheric instability, elevated moisture, and scattered convection through at least September 3–4. Cloud cover and rainfall suppress nocturnal radiative cooling by trapping longwave radiation and maintaining high dew points near 24–25 °C, which caps how far temperatures can fall. Clearer breaks between storms could allow modest additional cooling toward the lower 20s °C, while widespread clouds or showers would favor minima closer to or above 26 °C. Light winds limit mixing, further amplifying sensitivity to cloud timing. Ongoing weak-to-moderate El Niño conditions add a broader background of slightly elevated temperatures and regionally suppressed rainfall, yet the short-term wave dominates the 48-hour window. Updated model runs and real-time observations of convective coverage over the next day will be the main catalysts for any sharp shifts in market-implied odds.