May 20, 2026 12:19 AM

Hot and Sticky Weather for the First Week of September

SOUTHERN CALIFORNIA, CA. (Pain In The Pass) >> This week’s weather forecast for Monday September 1 through Friday September 5 for Southern California. Check out the 5-day forecast below in your area.

Cajon Pass/Inland Empire Valley Area Average Weather/Temps:

Monday will be hot, mostly sunny, and a high of 102°. Tuesday will be hot, mostly sunny with a chance of rain showers and thunderstorms, with a high of 101°. Wednesday will be hot, mostly sunny, and a high of 100°. Thursday will be hot, sunny, and a high of 98°. Friday will be hot, mostly sunny and a high of 96°.

High Deserts Area Average Weather/Temps:

Monday will be hot, sunny, windy, and a high of 102+°. Tuesday will be hot, mostly sunny with a chance of rain showers and thunderstorms, windy, and a high of 101+°. Wednesday will be hot, mostly sunny with a chance of thunderstorms, windy and a high of 100+°. Thursday will be hot, mostly sunny with a chance of thunderstorms, windy, and a high of 98+°. Friday will be hot, mostly sunny with a chance of thunderstorms, windy, and a high 96+°. Higher temps in the Barstow area.

Mountains Area Average Weather/Temps:

Monday will be warm, sunny, windy, and a high of 80°. Tuesday will be warm, mostly sunny with a chance of rain showers and thunderstorms, windy, and a high of 78°. Wednesday will be warm, mostly sunny with chance of and thunderstorms, windy and a high of 76°. Thursday will be warm, mostly sunny with a chance of thunderstorms, windy, and a high of 74°. Friday will be warm, mostly sunny with a chance of thunderstorms, windy, and a high of 73°.

*Timing of the Weather on each day can change.

There are more ways to follow the Pain In The Pass. Join the Traffic Group on Facebook with over 163,000 members. Join the group on MeWe. Like us on the NEW page on Facebook. Follow us on Instagram, and also follow us on Threads, and X aka Twitter.

loader-image
Cajon Pass
12:19 am, May 20, 2026
temperature icon 57°F
clear sky
Humidity: 20 %
Pressure: 1016 mb
Wind: 2 mph
Wind Gust: 4 mph
Clouds: 0%
Visibility: 10 km
Sunrise: 5:43 am
Sunset: 7:48 pm
  • Temperature
  • Precipitation
  • Rain Chance
  • Wind
  • Humidity
  • Pressure
2:00 am
temperature icon
52°/55°°F 0 mm 0% 3 mph 20% 1016 mb 0 mm/h
5:00 am
temperature icon
50°/53°°F 0 mm 0% 7 mph 19% 1015 mb 0 mm/h
8:00 am
temperature icon
60°/60°°F 0 mm 0% 5 mph 15% 1015 mb 0 mm/h
11:00 am
temperature icon
70°/70°°F 0 mm 0% 8 mph 10% 1014 mb 0 mm/h
2:00 pm
temperature icon
76°/76°°F 0 mm 0% 1 mph 8% 1011 mb 0 mm/h
5:00 pm
temperature icon
70°/70°°F 0 mm 0% 2 mph 9% 1009 mb 0 mm/h
8:00 pm
temperature icon
65°/65°°F 0 mm 0% 6 mph 21% 1011 mb 0 mm/h
11:00 pm
temperature icon
60°/60°°F 0 mm 0% 6 mph 27% 1012 mb 0 mm/h