More climate-resilient than 13% of Western resorts · 23% of all North American resorts
#132 of 152 in the West · #169 of 220 overall
What goes into it, compared with Western resorts:
* A ranking against the North American resorts we rate, not a grade out of 100: 100 = most resilient in the field, 50 = middle of the pack. Higher scores mean the resort's terrain and weather profile are more resilient in preserving winter conditions, both today and in a future of warmer temperatures.
Less rain risk than 13% of Western resorts · 15% of all North American resorts
#131 of 152 in the West · #186 of 220 overall
About 13.8% of winter precipitation falls as rain today, about 38% at +2°C.
How well Donner Ski Ranch's winter precipitation holds up as snow rather than rain. We rebuilt 40 winters of hourly weather at the resort's base, mid-mountain and peak, then estimated whether each hour's precipitation fell as rain or snow from temperature and humidity. To see what warming would do, we re-ran the same winters 1°C and 2°C warmer. The score is a ranking, not a grade: 100 = least rain risk in the field, 50 = middle of the pack.
When might +1°C and +2°C happen?
Roughly +1°C by the mid 2030s and +2°C around 2050 for North American ski country — sooner if emissions keep rising, possibly never if they fall fast. It's already about 0.7°C warmer than the 1986–2026 average these numbers start from.
These are local winter warming above the average of the 1986–2026 winters we rebuilt (centered around 2006), not the global “1.5°C / 2°C above pre-industrial” targets, which start from the 1800s. The world has warmed about 1.37°C since pre-industrial times and is warming about 0.27°C per decade (Indicators of Global Climate Change 2025); North America's land warms roughly 1.5× faster than that, fastest in winter (U.S. National Climate Assessment). A rough guide, not a forecast: real timing depends on future emissions and varies by region and year.
| 1986–2006 | 2006–2026 | +1°C*(mid 2030s) | +2°C*(2050) | |
|---|---|---|---|---|
| 7,780' Peak | 7.0% | 7.9% | 14.9% | 27.2% |
| 7,410' Mid | 11.5% | 12.8% | 23.1% | 37.2% |
| 7,030' Base | 17.7% | 19.4% | 31.5% | 45.2% |
The first two columns are the real observed weather record, split into two equal halves. * The +1°C and +2°C columns are stress tests: the full observed record replayed with that much warming added, so they show sensitivity to warming, not a forecast for a specific year. Elevations are rounded to the nearest 10 ft.
Full rain data, season-by-season history & resort comparisons →
How El Niño and La Niña winters affect Donner Ski Ranch →
More naturally skiable days than 34% of Western resorts · 53% of all North American resorts
#100 of 152 in the West · #105 of 220 overall
143 of 181 possible days today (Nov–Apr), about 108 at +2°C.
How many days a season Donner Ski Ranch has enough natural snow to ski, November through April. We simulated the snowpack day by day for 40 winters at the base, mid-mountain and peak — snow piling up, melting on warm days, and getting eaten away by rain — then ran the same winters 1°C and 2°C warmer.
When might +1°C and +2°C happen?
Roughly +1°C by the mid 2030s and +2°C around 2050 for North American ski country — sooner if emissions keep rising, possibly never if they fall fast. It's already about 0.7°C warmer than the 1986–2026 average these numbers start from.
These are local winter warming above the average of the 1986–2026 winters we rebuilt (centered around 2006), not the global “1.5°C / 2°C above pre-industrial” targets, which start from the 1800s. The world has warmed about 1.37°C since pre-industrial times and is warming about 0.27°C per decade (Indicators of Global Climate Change 2025); North America's land warms roughly 1.5× faster than that, fastest in winter (U.S. National Climate Assessment). A rough guide, not a forecast: real timing depends on future emissions and varies by region and year.
| Today | +1°C*(mid 2030s) | +2°C*(2050) | |
|---|---|---|---|
| 7,780' Peak | 150 | 142 | 127 |
| 7,410' Mid | 146 | 132 | 113 |
| 7,030' Base | 137 | 121 | 93 |
Warmer winters don't just turn some snowfall into rain. Rain also eats away the snow that's already on the ground, in four ways:
Our model simulates all four, using a simplified version of the snowmelt model the U.S. National Weather Service uses for river forecasting.
Natural snow only — no snowmaking or grooming, so resorts that make a lot of snow stay open longer than these numbers. “Skiable” means at least 3 inches of snow-water in the snowpack (roughly a 12–18 inch settled base). Snowfall is scaled to match Donner Ski Ranch's average snowfall. Melt follows the sun on Donner Ski Ranch's actual runs: shady, north-facing slopes hold snow longer than sunny ones. * Stress tests, not forecasts: the same winters replayed warmer. Checked against 40 years of real snowpack measurements at 105 SNOTEL stations across the West, where it's typically within about a week of the real season length.
Terrain holds snow better than 11% of Western resorts · 9% of all North American resorts
#134 of 150 in the West · #197 of 216 overall
Donner Ski Ranch's runs get 14% more winter sun than the same slopes would facing every direction equally. Typical resort: 17% less.
How well Donner Ski Ranch's runs are oriented to hold onto snow. North-facing slopes get less direct sun and keep snow longer; south-facing slopes lose it faster. We measured the direction and steepness of 1 mapped runs and compared the sunshine they receive with what the same slopes would get if they faced every direction equally, so this score reflects terrain orientation only, not latitude or elevation (those are covered by the rain score above).
Share of mapped terrain facing each direction. Trail data © OpenStreetMap contributors via OpenSkiMap.