When Does Tioga Pass Open? What 47 Springs of Data Say

The short answer

Tioga Road usually opens in late May or early June. Since 1980 the median opening has been May 24, the earliest was April 29 (1988) and the latest was July 22 (2023). In 2026 it opened on May 15, the earliest in eleven years.

If you want to guess this year’s date, look at one number: the April 1 snowpack for the Tuolumne River drainage, which the park publishes each spring. Then use the estimator below.

Snow explains most of it

Plot every spring since 1980 and the pattern is plain. The correlation between April 1 snowpack and opening day is 0.83, which means snow alone accounts for about 70% of the year-to-year swing. Every 10 points of snowpack adds about three days.

The rest is spring weather. A late storm in April or May can bury a road that crews have already cleared, and a warm spell can melt them a month ahead. That noise is real: half of all years land within about seven days of the line, and a few miss by two weeks either way.

The two weeks the 2020s cannot explain

Here is the part worth sharing. Measure each spring against what its snow predicts, and the last seven years stand apart. Every one of them opened late. Not most of them. All seven.

The 2020s averaged 86% of normal snowpack, less snow than the decades before, and still opened on June 7 on average, against May 26 for 1980 to 2019. On snow alone, the decade should have been early.

Some of that lateness has a name. In 2020 the park was closed for COVID and reopened by reservation, and the road opened 34 days behind its snow. In 2023, record snow damaged the road and the buildings along it, and a ranger told KQED the road could not open until there was housing for the rangers who patrol it. But 2021, 2022, 2024, 2025 and 2026 had no single crisis, and they still ran six to sixteen days late.

So which matters most: snow, plows or budget?

1. Snowload, by a wide margin. It explains about 70% of the variation on its own, across 47 springs. Nothing else comes close.

2. Budget and staffing, the likely cause of the recent drift. The data cannot see budgets directly, so this is an inference, but it fits. The gap opened in the 2020s, the same years the park ran short of people: the Yosemite Conservancy put the National Park Service’s staffing deficit at about 30% in 2024, before the federal staffing cuts of 2025. Opening the road is not only plowing. Rangers have to be housed and on patrol, campgrounds and restrooms readied, and avalanche paths and rockfall cleared and checked. Each of those waits on people.

3. Plow technology, no visible effect. If better machines moved the date, the gap against the snow line would shrink over time. It has grown, by about four days a decade. Between 1957 and 1979, with older equipment, the road opened on May 18 on average, and in the dry springs of 1976 and 1977 it opened on April 10 and April 8. Since 1980 it has never opened before April 29. Clearing begins on or about April 15 by park practice, so in a light year the calendar, avalanche safety and crew size set the date, not the horsepower of the blowers.

What it means for your trip

Plan a Tuolumne Meadows trip for after mid-June and you will almost always be fine. In a light snow year, late May works. In a big year, think July. Watch the park’s April 1 snow number, and add a week or so of cushion for the way the 2020s have run.

Closing is a different story. The road usually closes around mid-November with the first big storm, and the closing date has nothing to do with last spring’s snow.