How often does the Grapevine close?

Caltrans puts the average at 3 to 5 full closures between October and April, usually 4 to 6 hours each, though some last more than 24 hours. Closures are announced by the CHP and Caltrans; this page shows active NWS warnings for the pass.

Do I need chains on the Grapevine?

No. Unlike I-80 over Donner Pass, chains are not used on the Grapevine: the snow is usually limited to the summit and traffic is too heavy for chain-removal areas. When snow sticks the CHP escorts traffic, and when that is not enough I-5 closes.

When will the Grapevine reopen?

The CHP and Caltrans do not forecast reopening times. Crews plow, sand, and de-ice after the storm, and road surfaces can be 4 to 10 degrees colder than the air. Check Caltrans QuickMap for the current status.

I-5 · CA

I-5 over the Grapevine (Tejon Pass): road conditions right now

Santa Clarita, CA to Bakersfield, CA

I-5 between Santa Clarita and Bakersfield crosses Tejon Pass at 4,144 feet, then drops down the Grapevine, a 6% grade for 5 miles, into the San Joaquin Valley. Caltrans says snow and ice close it fully an average of 3 to 5 times between October and April, cutting the main road between Southern and Northern California.

Checking the forecast, NWS alerts, and DOT feeds for I-5 right now…

Why this stretch is hard in winter

Caltrans starts Operation Snowflake when forecasters expect heavy snow at 4,500 ft or lower, which puts the 4,144 ft summit in play.
Once snow sticks to the road, the CHP paces or escorts groups of drivers over the pass. If that is not enough, I-5 closes, with northbound traffic stopped at Lake Hughes Road and southbound at Grapevine Road.
Closures typically last 4 to 6 hours and some last more than 24. Neither the CHP nor Caltrans forecasts a reopening time.
Detours depend on the closure phase: SR-58 and SR-166 first, then SR-166 alone, then SR-46 and SR-41 to US-101, and in the worst storms none at all.

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-5

How often does the Grapevine close?: Caltrans puts the average at 3 to 5 full closures between October and April, usually 4 to 6 hours each, though some last more than 24 hours. Closures are announced by the CHP and Caltrans; this page shows active NWS warnings for the pass.
Do I need chains on the Grapevine?: No. Unlike I-80 over Donner Pass, chains are not used on the Grapevine: the snow is usually limited to the summit and traffic is too heavy for chain-removal areas. When snow sticks the CHP escorts traffic, and when that is not enough I-5 closes.
When will the Grapevine reopen?: The CHP and Caltrans do not forecast reopening times. Crews plow, sand, and de-ice after the storm, and road surfaces can be 4 to 10 degrees colder than the air. Check Caltrans QuickMap for the current status.

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-15 over Cajon Pass · all corridors