I-80 Donner Pass Road Conditions

Cross the Sierra on I-80 — know whether Donner Pass is open, and the safest hour to climb, before you leave. This guide introduces seasonal risks along the I-80 corridor. Open your route in TripCaptain to check the forecast, compare departure times and follow changes as you travel.

Winter Driving Pattern

I-80 climbs from around 550 m (1,800 ft) near Colfax to roughly 2,160 m (7,100 ft) at Donner Summit before dropping to Truckee, and that climb sits under one of the snowiest interstate crossings in the country — often more than 10 m (33 ft) of snow in a single season. From November through April, Pacific storms ride in off the ocean and stall against the crest, stacking heavy snow, poor visibility, and gusting wind over the summit while Colfax may still be sitting in the rain. When a storm peaks, posted traction laws tighten from chains-recommended to chains-required, and a full whiteout or a slide can close the highway outright for 24 to 48 hours with no marked way around. Truckee adds a second hazard: cold air pools in the basin overnight and can drop below −20 °C (−4 °F), glazing the road with black ice long after the snow has stopped falling. The difference between an open pass and a stranded night is often just a few hours of departure timing. TripCaptain checks the storms and cold moving over your exact departure window, so you leave knowing whether the summit is about to close and which hour gives you the clearest run.

Common Hazards on This Corridor

• Chain-control snow at Donner Summit: Storms stack more than 10 m (33 ft) of snow on the crest in a season; when they peak, posted traction laws move from chains-recommended to chains-required and visibility over the summit can fall below 400 m (¼ mile).
• Whiteout & avalanche closures: A full whiteout or a slide can shut I-80 over the summit with no marked detour, sometimes for 24 to 48 hours; the official pass status decides whether the road is open before you commit to the climb.
• Black ice around Truckee: Cold air pools in the Truckee basin overnight and glazes the road with black ice that is hardest to see at dawn, often long after the last snow has stopped falling.
• Deep overnight cold: The Truckee cold pool can drop below −20 °C (−4 °F) on clear winter nights, freezing washer fluid and hardening slush into ruts, which makes any stall on the shoulder dangerous.

Frequently Asked Questions

Is I-80 over Donner Pass safe to drive in winter?

It can be, but conditions change fast. In clear, dry weather the crossing is a straightforward interstate climb from about 550 m (1,800 ft) at Colfax to 2,160 m (7,100 ft) at Donner Summit. During a Pacific storm the same stretch can go from wet pavement at the bottom to a chains-required whiteout at the top within an hour, and the pass sometimes closes entirely. Check the official pass status and the forecast for your departure window before you go — TripCaptain checks the storms and cold moving over your exact route and departure time and tells you whether the summit is about to close.

How often does Donner Pass close, and for how long?

In a busy winter, I-80 over the summit can close several times a month during Pacific atmospheric-river storms. Most closures last a few hours while crews plow and clear stuck vehicles, but a severe whiteout or an avalanche can shut the highway for 24 to 48 hours with no marked detour — the alternate mountain routes usually close in the same storm. Closures are most common from November through April.

Do I need winter tires or chains on I-80 over Donner Pass?

In winter, yes — carry chains. When snow is falling, posted traction laws are enforced at the pass and tighten in stages: first chains or approved traction devices are recommended, then required on vehicles without four driven wheels and winter tires, then required on nearly everything. Even on a clear day, if snow is in the summit forecast, carry chains that fit your vehicle and know how to fit them before you leave.

What is the best time of day or year to cross Donner Pass?

Late spring through early fall is the easiest window, with the summit usually dry and open. In winter, aim to cross in daylight and between storms rather than during a system's peak, and give the road a few hours after a storm for crews to clear it and traction laws to ease. Early mornings bring the worst black ice around Truckee, so a mid-morning departure is often safer than a pre-dawn one.

How high is Donner Pass, and how long is the corridor?

This corridor follows I-80 across the Sierra Nevada from Colfax, at about 550 m (1,800 ft), up over Donner Summit at roughly 2,160 m (7,100 ft), then down to Truckee — about 85 km (53 mi) end to end. In that short distance you gain more than 1,600 m (5,300 ft) of elevation, which is why the weather at the summit can be nothing like the weather where you started.

What should I carry, and what if I get stranded on the pass?

Before you start the climb, carry chains that fit, a full tank or charge, warm layers and blankets, water, snacks, a flashlight, and a phone charger. If you're caught in a closure or a stall, stay with your vehicle where crews can find you, keep the exhaust pipe clear of snow, and run the engine only in short bursts to stay warm. Because a summit closure can last a day or more, plan for the possibility of a long wait, and don't start the climb late in the day if a major storm is moving in.

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