Strengthening El Niño conditions, now carrying over 90% probability according to NOAA’s Climate Prediction Center, represent the primary driver shaping market-implied odds for the first measurable snowfall (≥0.1 inch) in monitored cities. This pattern typically steers a more active storm track southward while favoring drier conditions across the northern Rockies and Pacific Northwest, potentially delaying or advancing first snow depending on latitude and elevation. Current September outlooks from the National Weather Service show above-normal temperatures across much of the contiguous U.S., with snow probability products offline until mid-month and no qualifying accumulations reported at stations such as Chicago O’Hare, Detroit, or Central Park. Traders should monitor upcoming 6–14 day CPC discussions and the October–December seasonal update for shifts in ridge-trough positioning that could alter early-season probabilities. Historical median first-snow dates place most Midwest and Northeast cities between mid-November and mid-December.