I-15 · CA / NV
I-15 over Cajon Pass: road conditions right now
Los Angeles, CA to Las Vegas, NV
Cajon Pass (3,777 ft) between San Bernardino and the High Desert is the one place on the LA–Vegas drive where snow closes the road. It happens a few times each winter and strands thousands because nobody expects it.
Checking the forecast, NWS alerts, and DOT feeds for I-15 right now…
Why this stretch is hard in winter
- A cold Pacific storm can put snow on the pass while it rains in San Bernardino 20 miles away.
- The CHP closes I-15 at the bottom on both sides when spinouts pile up; there is no equivalent alternate.
- Beyond Barstow, the high desert to Primm can see blowing dust and, rarely, snow near Mountain Pass (4,730 ft).
- Sunday-evening Vegas traffic plus any closure means multi-hour backups at Cajon.
What this page checks
- Hourly forecast at every checkpoint for the time you would be there: temperature, precipitation type and rate, gusts, visibility.
- Active National Weather Service watches, warnings, and advisories on the route.
- Snow on the ground (NOAA SNODAS) and the Weather Prediction Center winter impact outlook.
- Pavement temperature and surface state from state DOT road sensors, when you are leaving within a few hours.
- Chain controls, closures, and winter road condition reports from state DOT feeds where they are published openly.
- Seasonal closures of mountain roads the router might otherwise use.
Official sources for this corridor
Questions drivers ask about I-15
- Does it really snow on I-15 to Las Vegas?
- Yes, at Cajon Pass and occasionally at Mountain Pass near the Nevada line. Closures are usually a few hours but have lasted overnight. This page checks forecast temperature and precipitation at the pass for the hour you would be there.
Conditions change by the hour. This page is a planning aid built on public forecasts and DOT feeds; the road authority linked above has the final word on closures and chain requirements.
Other corridors: I-80 across Wyoming · I-70 through the Colorado mountains · I-80 over Donner Pass · I-90 over Snoqualmie Pass · I-84 through the Blue Mountains · I-90 across South Dakota · all corridors