Extreme heat impacts Western U.S. as historic El Niño looms

A record-breaking October heat wave is affecting much of the Western United States. In California, nearly 18 million people are facing major to extreme heat risks, with temperatures expected to reach the mid-90s to 100 degrees in coastal mesas and higher terrain. Combined with heat advisories in Arizona, approximately 23 million people in the region are under extreme heat warnings.

Looking ahead, meteorologists are monitoring strengthening El Niño conditions. NOAA reports a greater than 90% chance of a very strong event this fall and winter. AccuWeather predicts a potentially historic El Niño, which could be the strongest since 1950, influencing weather through early spring 2027. This pattern is expected to increase flooding risks across parts of the West and South while favoring warmer conditions in the northern U.S.

Additionally, a Kelvin wave moving toward the California coast is expected to raise sea levels by half a foot or more, potentially contributing to coastal erosion and elevated water levels for several months.