A persistent heat dome and strong high pressure have driven an unprecedented October heat wave across Southern California, pushing downtown Los Angeles to five consecutive days at or above 100°F through Tuesday as of October 7. National Weather Service observations confirm record daily highs, including 104°F Monday, with temperatures running 15–25°F above seasonal norms. Latest model guidance and NWS forecasts now show only a 30% chance of reaching 100°F Wednesday, followed by gradual cooling into the mid-90s Thursday under an Extreme Heat Warning expiring that evening. Strengthening onshore flow and weakening high pressure are expected to drop highs further Friday and into the 70s by the weekend, limiting extension beyond five days while leaving modest residual risk for six or more if the dome lingers. Market-implied odds reflect this near-term forecast consensus from authoritative monitoring agencies.