Catch up on the Southwest’s weather forecast for July 21, 2025. From sunny skies to imminent thunderstorms, understand how the weather will change in your region tonight.

Welcome to your Southwest weather forecast for the evening. Tonight, Salt Lake City will see partly cloudy skies with a brisk breeze making for a pleasant evening. Meanwhile, Flagstaff prepares for scattered thunderstorms, and Los Angeles enjoys a dry, cool afternoon. Dive deeper into temperature trends, potential rain forecasts, and safety tips for navigating fluctuating conditions across the Southwest. Detailed insights for the next 7 days are just a scroll away!
The Southwest is mostly dry, but expect scattered thunderstorms over Flagstaff and eastward into New Mexico. Cedar City is seeing cloud cover with potential showers moving in. Ely and areas near Salt Lake City are experiencing clear conditions. San Diego and Los Angeles remain dry, with no precipitation expected.
In Salt Lake City this evening, temperatures start at a warm 90 degrees at 9 PM, descending to 82 degrees by 1 AM. Expect mostly cloudy skies transitioning to partly cloudy as the evening progresses. Winds are from the south-southeast, starting at 15 miles per hour and easing to 11 miles per hour by early morning.
Tonight, Las Vegas will cool down to 75 degrees, a relatively mild evening. In contrast, Flagstaff dips to a brisk 51 degrees, signaling a notable chill in the area. San Francisco will see a low of 57 degrees, while Fresno drops to 61. Keep an eye on cooler spots like Reno, which will reach 56 degrees.
Tomorrow, high temperatures in the Southwest are set to soar. Las Vegas will hit a scorching 101 degrees, while Phoenix follows closely with a high of 99. Bakersfield is expected to reach 93 degrees, and Fresno will warm up to 90. Coastal areas will enjoy milder temperatures, with San Diego at 74 degrees and Los Angeles peaking at 73.
Expect clear and sunny weather across much of the desert Southwest tomorrow, with temperatures rising steadily throughout the day. However, be prepared for afternoon thunderstorms popping up over the mountainous regions of Arizona and Southern California. The storms could bring heavy rain and isolated strong winds, potentially leading to flash flooding in low-lying areas. The weather system is expected to move eastward, with conditions clearing again by the evening. Make sure to stay hydrated and cautious on the roads, especially in areas prone to sudden downpours.
The UV index in Salt Lake City today is very high at 9, making sun exposure risky with a burn time of approximately 15 minutes. Both today and tomorrow, take extra precautions by wearing hats, sunglasses, and applying sunscreen.
For the 7-day forecast in Salt Lake City: Monday: Partly cloudy skies, with highs reaching 90 degrees and cooling down to 70 degrees at night. Tuesday: Clear skies ahead, expect a high of 90 degrees and a low of 66 degrees. Wednesday: Mostly clear weather, with a high of 90 degrees and an evening low of 67 degrees. Thursday: The day will be partly cloudy, temperatures peaking at 90 degrees and dipping to 65 degrees overnight. Friday: Mostly clear conditions, the high will be 93 degrees, with a low of 66 degrees. Saturday: Enjoy partly cloudy skies with the temperature climbing to 94 degrees and dropping to 66 degrees in the cool of the night. Sunday: A clear day, wrapping up with a high of 96 degrees and a nighttime low of 67 degrees.