WESTERN US — The National Weather Service issued heat advisories and fire weather alerts across the Western U.S. on August 1, 2026, as a record-breaking heat wave brought extreme temperatures and heightened wildfire risk to states from Arizona to Montana.

Phoenix was forecast to reach 116 degrees on August 1, tying the daily record. The National Weather Service expected the worst heat conditions in Phoenix on August 1-2, forecasting highs of 111 to 117 degrees through August 3. Phoenix was forecast to climb to 115 degrees on August 2, which is 1 degree above the record for that date.

"Strong high pressure will keep temperatures near record levels while suppressing most monsoon activity in Phoenix," said Sean Benedict, lead meteorologist at the National Weather Service in Phoenix. Temperatures in Phoenix fell no lower than 94 degrees early August 1, a low that was 9 degrees above normal and 1 degree shy of the record-warm low set in 2008. Overnight lows in Phoenix were forecast to be 87 to 93 degrees.

The National Weather Service issued an Extreme Heat Warning for Kofa and Central La Paz until August 3. More than 200 hikers are rescued each year from Phoenix's desert parks and mountain preserves. Storms are expected to remain concentrated over the White Mountains and southeastern Arizona, with isolated thunderstorms could develop in far southeastern Gila County beginning August 2.

In Nevada, the National Weather Service forecast a high of 115 degrees Fahrenheit (46 degrees Celsius) in Las Vegas on Saturday, August 1, 2026. This forecast high of 115F in Las Vegas was the hottest temperature of the year for the city, standing 10 degrees above normal. Meteorologists warned of dangerous heat in Las Vegas through Sunday, with a high expected to be 114F. Overnight lows in Las Vegas were in the upper 80s to low 90s.

"There's just no relief overnight," said Morgan Stessman, a National Weather Service meteorologist. People were urged to stay indoors and hydrated to avoid heat-related illnesses. Relative humidity in the afternoon in Nevada was bottoming out in the single digits in quite a few places.

El Centro, California, was expected to hit a record 118F (48C). In Montana, Great Falls was forecast to reach a record 104F (40C), surpassing its previous record high of 101F (38C). Helena, Montana, was expected to match or surpass its record high of 102F (39C). The entire east side of Montana was under an extreme heat warning on Saturday, August 1, 2026.

Temperatures in Billings could reach 106F (41C), following a July 12, 2026, event where Billings reached 111F (44C). "That was a rare heat wave," said Jeff Kitsmiller, a National Weather Service meteorologist. "This one fits for this time of year." By Sunday, much of Montana will have highs in the 70s. The Montana Rescue Mission in Billings opened its doors earlier than usual on Saturday to provide relief from the heat, while Great Falls Parks and Recreation's four swimming pools and three splash pads were crowded with people seeking cool water.

Meteorologists warned of critical fire weather conditions in eastern Washington, northern Idaho, and western Montana due to dry weather and powerful winds. The National Weather Service issued a "particularly dangerous situation" Red Flag Alert for Eastern Washington, rating the weather risk as "extreme." A red flag alert was issued for eastern Oregon, and most of Montana was under a red flag warning. The U.S. Forest Service stated there is an enhanced wildfire risk through Sunday in most of Southern California except for the coastline.

A cold front with sustained winds of 15 to 30 miles per hour and gusts up to 50 miles per hour was forecast to move across eastern Washington and northern Idaho on Saturday and into western Montana. The National Weather Service issued a fire weather watch for Saturday stretching from the east side of the Cascades into central Montana. Avista warned customers that conditions may prompt the electricity utility to preemptively shut off power in some areas on Saturday to mitigate fire risk.

Areas around Clarkston, Asotin, the Lewiston Orchards, Orofino, Greer, Kamiah, Kooskia, Stites, Grangeville, Elk City, and Pierce are subject to potential power shutoffs. Potential power shutoffs could start at 4 p.m. Saturday, but no decisions had been made yet. Avista turned off power in the Asotin and Kamiah areas on Saturday, July 25, 2026.

The Cascade and Wolf Creek fires on opposite sides of the Selway River in the Nez Perce-Clearwater National Forest have burned nearly 600 acres. Winds may briefly clear out smoke from wildfires in Oregon, but the effect may be short-lived. Smoke generated in north central Washington and British Columbia is expected to carry down into the Columbia Basin and Lewiston area, increasing smoke threat going into Monday. August is typically the peak of fire starts across much of the forested areas of northern Idaho and eastern Washington.

The high-pressure system should weaken slightly on Monday, August 3, 2026. "Temperatures in Phoenix could fall by 1 to 3 degrees on Monday, but dangerous heat will continue," said Sean Benedict. The Weather Service listed a 10% chance of Phoenix-area thunderstorms beginning August 4.

This year’s weather is expected to be affected by El Nino. The current El Nino is expected to rank as among the most intense since the weather service began tracking the phenomenon in 1950. The current El Nino has broken records for intensity at its early stages, United Nations officials warned on Friday, July 31, 2026.

The National Weather Service issued its first-ever heat advisory for Anchorage and large parts of Southcentral Alaska, including the Mat-Su, a swath of the Kenai Peninsula, and portions of the Copper River Valley. High temperatures in Anchorage were forecast to reach the mid-70s, while the Central Copper Valley, McCarthy, and Southern Copper Valley were expected to see slightly warmer weather with highs in the upper 70s or higher.

Why It Matters

The convergence of record-breaking temperatures across multiple states and critical fire weather conditions creates immediate risks for public health and safety. Overnight lows failing to drop significantly prevent physical recovery from the heat, while dry winds and single-digit humidity elevate the potential for rapid wildfire spread. These conditions force emergency services to expand operations and prompt utilities to consider preemptive power shutoffs to mitigate ignition sources.