Recent ensemble forecasts from Météo-France and the European Centre for Medium-Range Weather Forecasts (ECMWF) place the expected daily maximum in Paris on May 22 near 27–29 °C under partly cloudy skies and light southerly flow, explaining why those outcomes currently command the highest market-implied probabilities. Model spread remains notable because small differences in boundary-layer moisture and afternoon insolation can shift the peak by 1–2 °C, while any increase in low-level cloud or a slight wind shift would favor the 26–28 °C cluster already priced at over 40 percent combined. Historical May climatology for the Paris basin shows typical maxima of 18–22 °C, so the current warmer pattern reflects a transient ridge that traders are weighing against the risk of rapid cooling if a frontal passage arrives earlier than projected. Final high-resolution runs and surface observations issued overnight will provide the last updates before the market resolves against official station readings.