Current ensemble forecasts from Météo-France and the European Centre for Medium-Range Weather Forecasts place Paris's maximum temperature on May 18 in the 15–17°C range, with the tightest clustering around 15–16°C. This positioning stems from a lingering cool Atlantic airstream and increasing cloud cover that limits daytime heating, keeping readings slightly below the late-spring climatological average of 18–19°C. Model spread arises mainly from uncertainty in the exact timing and strength of an approaching frontal boundary, which could either enhance or suppress afternoon warming by a degree or two. The market's near-even split between the 15°C and 16°C outcomes directly mirrors this narrow forecast envelope two days ahead of resolution at the Paris-Le Bourget station.