California (CA) Road Conditions & Chain Controls

QuickMap is the traveler information map run by Caltrans, at quickmap.dot.ca.gov. It is the state's answer to what the road is doing at this minute, and Caltrans publishes on it:

• Active chain control requirements statewide, refreshed every minute
• Still camera images — chosen over video so the map keeps answering under load
• Active lane closures, refreshed every five minutes; planned ones are left off
• Full closures
• CHP incident reports
• Changeable message signs, but only the ones currently displaying something
• Traffic speeds, and border wait times at the Mexican crossings

QuickMap and the conditions on this page

The chain-control layer is the one worth pairing with this page, because the two answer questions that only look alike. Caltrans states the restriction that is in force on Donner, the Grapevine or Mount Rose right now — a legal requirement it imposes and lifts through the day, which nothing here derives or guesses at. What this page adds is the surface underneath it: whether the pavement is wet, slushy, snow-covered or iced, and how cold it is at the summit as against the two climbs. A dry road under an R2 is a different drive from a glazed one, and QuickMap reports the same R2 for both.

13 current reports along the route, including 1 full closure. The 8 most serious are listed below. Always check with the responsible state DOT before setting off.

• Road closed

  I-5 closed

  Mainline closure. Work: Accident Investigation. Lanes closed: All. Near Pacoima, Los Angeles County.

  Pacoima • South • CA • Ongoing

• Lanes blocked

  I-5 conventional hwy closure (lanes 2)

  Conventional Hwy closure. Work: Bridge Inspection. Lanes closed: 2. Near Lakehead, Shasta County.

  Lakehead • North / South • CA • Until Oct 9, 10:01 PM

• Lanes blocked

  I-5 mainline closure (lanes 1, 2)

  Mainline closure. Work: Striping Operation. Lanes closed: 1, 2. Estimated delay: 5 min. Near Woodland, Yolo County.

  Woodland • North • CA • Until Oct 9, 1:59 PM

• Lanes blocked

  SR-273 mainline closure (lanes 1, 2)

  Mainline closure. Work: Striping Operation. Lanes closed: 1, 2. Near Anderson, Shasta County.

  Anderson • South • CA • Until Oct 9, 3:01 PM

• Lanes blocked

  I-5 conventional hwy closure (lanes 1, 2)

  Conventional Hwy closure. Work: Bridge Work. Lanes closed: 1, 2. Near Lakehead, Shasta County.

  Lakehead • North / South • CA • Until Oct 12, 7:01 PM

• Lanes blocked

  I-5 mainline closure (lanes LShoulder, 1, 2, RShoulder)

  Mainline closure. Work: AC Paving. Lanes closed: LShoulder, 1, 2, RShoulder. Near Woodland, Yolo County.

  Woodland • South • CA • Until Oct 9, 11:30 AM

• Lanes blocked

  I-5 on ramp closure

  On Ramp closure. Work: AC Paving. Lanes closed: All. Near West Sacramento, Yolo County.

  West Sacramento • North • CA • Until Oct 9, 11:30 AM

• Lanes blocked

  I-5 off ramp closure

  Off Ramp closure. Work: Striping Operation. Lanes closed: All. Estimated delay: 5 min. Near Zamora, Yolo County.

  Zamora • North • CA • Until Oct 9, 1:59 PM

Interstates Through California, Road by Road

Each stretch has its own live conditions, closures and cameras for the California miles only — the weather 500 miles away on the same interstate says nothing about this drive.

• I-5 California Road Conditions 797 mi
• I-10 California Road Conditions 243 mi
• I-15 California Road Conditions 287 mi
• I-40 California Road Conditions 155 mi
• I-80 California Road Conditions 201 mi

NOAA 1991–2020 Climate Normals, from 6 weather stations in California. A dash is a figure that station does not report, not a zero.

Snowfall across California is not one number: Los Angeles averages 0" a year and Truckee averages 202.6".

Every figure above is a town or a city. The summits are a different climate: Cajon Pass, Donner Pass (Donner Summit, I-80), The Grapevine (Tejon Pass, I-5) each has its own page with the readings at the top and a six-day summit forecast.

Driving in California Month by Month

What the road normally throws at you, month by month, from NOAA's 1991–2020 normals for California's own stations. Each month names its dominant hazard and the place that measured it — this is what the month is usually like, not a forecast and not a restriction.

• January Quiet 8.5 wet days at San Francisco is the most the normals report
• February Quiet 7.7 wet days at San Francisco is the most the normals report
• March Quiet 7 wet days at San Francisco is the most the normals report
• April Quiet 3.7 wet days at San Francisco is the most the normals report
• May Quiet 2.1 wet days at San Francisco is the most the normals report
• June Heat 11.8 days above 90°F at Sacramento
• July Heat 21.1 days above 90°F at Sacramento
• August Heat 19.2 days above 90°F at Sacramento
• September Heat 12.9 days above 90°F at Sacramento
• October Quiet 2.2 wet days at Sacramento is the most the normals report
• November Quiet 5.4 wet days at San Francisco is the most the normals report
• December Quiet 8 wet days at San Francisco is the most the normals report

California Chain Controls: R-1, R-2 and R-3

The sign states the rule; R-1, R-2 and R-3 are what you hear on the radio. Caltrans does not post signs with those designations — they are shorthand it and the CHP use internally, which traffic reports then repeat. What is posted at the roadside is the requirement and the list of who is exempt, and which of the three levels is up decides whether snow tires are enough — or whether anything is. Caltrans is explicit that the sign wins: follow it, and any instruction from Caltrans or CHP staff at the checkpoint, even where it differs from a broadcast report or from a page like this one.

What R-1, R-2 and R-3 require

A snow-tread tire here carries MS, M/S, M+S or the words MUD AND SNOW on the sidewall and has at least 6/32-inch of tread — the same depth as Colorado's 3/16-inch, written the other way round. Chains means any approved traction device: link chains, cable chains, textile snow chains, hub-mounted and automatic chains all count, and Caltrans and the CHP can turn away a vehicle whose device does not meet the Vehicle Code.

R-1

Chains on everything except a car or light truck under 6,000 lbs with snow tires on at least two drive wheels — and that car still has to be carrying chains.

R-2

Chains on everything except four-wheel drive under 6,500 lbs with snow tires on all four wheels, again only if a set of chains is in the vehicle. This is where two-wheel drive stops being enough however good the tires are.

R-3

Chains on all vehicles, no exceptions, four-wheel drive included. Caltrans notes a highway is often closed before it goes this far, so R-3 usually means the road is about to shut.

Enforcement

Non-compliance is a citation from the California Highway Patrol, which is who enforces chain control rather than Caltrans; no fixed amount is published.

How you will know it is active

• Signs posted along the controlled stretch, stating the requirement and who is exempt from it — not the R-number, which Caltrans does not sign
• QuickMap, which carries statewide chain controls and refreshes them every minute
• The Caltrans Highway Information Network on 800-427-7623, which covers California and western Nevada, the Lake Tahoe and Reno area included

Which requirement is posted changes with the storm and with the elevation. This page does not carry it — QuickMap ↗ is the authority before you set off.

Source: Caltrans, checked September 22, 2026.

Related Roads

California Road Weather FAQ

Are any roads closed in California right now?

Yes — one full closure is reported on the interstates in California as of Oct 8, 2026 8:17 PM PDT. 12 lane closures, roadworks or restrictions are in force. They are listed under closures and road blocks on this page.

What are California road conditions today?

The map on this page colors the interstates across California by what is on the pavement right now — dry, wet, slush, snow or ice — from radar and surface data, last updated Oct 8, 2026 7:58 PM PDT. Right now temperatures run from 61°F to 99°F and the strongest wind is 15 mph.

What do R-1, R-2 and R-3 mean in California?

A snow-tread tire here carries MS, M/S, M+S or the words MUD AND SNOW on the sidewall and has at least 6/32-inch of tread — the same depth as Colorado's 3/16-inch, written the other way round. Chains means any approved traction device: link chains, cable chains, textile snow chains, hub-mounted and automatic chains all count, and Caltrans and the CHP can turn away a vehicle whose device does not meet the Vehicle Code.

What happens if you ignore a California chain control?

Non-compliance is a citation from the California Highway Patrol, which is who enforces chain control rather than Caltrans; no fixed amount is published.

Do I need chains to drive I-80 over Donner Pass in winter?

Not always. It depends which of 3 requirements is posted: "R-1" — chains on everything except a car or light truck under 6,000 lbs with snow tires on at least two drive wheels — and that car still has to be carrying chains. "R-2" — chains on everything except four-wheel drive under 6,500 lbs with snow tires on all four wheels, again only if a set of chains is in the vehicle. This is where two-wheel drive stops being enough however good the tires are. "R-3" — chains on all vehicles, no exceptions, four-wheel drive included. Caltrans notes a highway is often closed before it goes this far, so R-3 usually means the road is about to shut.

Do I need chains in California with four-wheel or all-wheel drive?

You have to carry them either way. All-wheel drive counts as four-wheel drive here, and no vehicle may enter a chain control area without a set of chains for one drive axle in it. Under R-2 a four-wheel or all-wheel drive vehicle under 6,500 lbs with snow tires on all four wheels may drive without them fitted; under R-3 there is no exemption for anyone. Towing a trailer means chains on a drive axle whatever you are driving, and a trailer with brakes needs them on at least one axle of its own.

Which interstates run through California?

California has 5 through interstates on this site: I-5, I-10, I-15, I-40 and I-80 — about 1,673 miles of interstate across the state. Each has its own page for the California stretch.

Are there mountain passes in California?

Yes — 3 on this site: Donner Pass at 7,239 ft, The Grapevine at 4,144 ft and Cajon Pass at 3,777 ft. Each has its own summit page.

Are there live traffic cameras in California?

Yes. This page shows 6 live views in California from the state transportation departments' own camera feeds, further down the page, refreshed each time you load it.

How often are California road conditions updated?

The road surface and weather layers are rebuilt whenever this page is opened with data more than ten minutes old, and refreshed on a schedule in between, so nothing here is more than about two hours old even on a road nobody has looked at. Closures and road blocks are re-imported from the state 511 feeds every fifteen minutes, and the written state-by-state summaries are refreshed daily. Every section on this page carries the time its data was fetched.