Crowd score
Formula: 100 − (this month's visits ÷ park's peak month visits) × 100. Each park scored against its own peak, not against other parks.
Source: NPS Visitor Use Statistics Data Package 2025, Recreation Visits (TRV), 5-year monthly mean (2021-2025). Reproduce these numbers on the NPS IRMA Stats portal.
Reading it: July at Bryce Canyon reads 0 (peak). November reads 76 (nearly empty). A 50 means about half the park's peak crowd.
Weather score
Formula: weatherScore = round(max(0, min(100, dayComfort − precipPenalty − snowPenalty − freezePenalty))). The piecewise day-comfort function is continuous at every boundary.
- Day comfort:
tmax < 50°F →
max(10, (tmax − 20) × 2) (cold tail);
50–60°F → 60 + (tmax − 50) × 4 (ramp to 100);
60–78°F → 100 (plateau);
78–85°F → 100 − (tmax − 78) × 5 (ramp to 65);
> 85°F → max(30, 65 − (tmax − 85) × 5) (hot tail).
- Precip penalty:
max(0, prcpIn − 1.5) × 8; kicks in above 1.5 in / month.
- Snow penalty:
snowIn × 2.5.
- Night-freeze penalty:
max(0, 32 − tmin) × 1.5 when tmin < 32°F.
Source: NOAA NCEI U.S. Climate Normals 1991-2020, station Bryce Canyon NP HQRS, UT (USC00421008, 7,890 ft).
Caveat: The Bryce Canyon NP HQRS cooperative observer station sits inside the park at ~7,890 ft, essentially the rim elevation band where the Visitor Center (~7,894 ft), Sunrise Point (~7,950 ft), Sunset Point (~8,000 ft), and the four iconic amphitheater viewpoints all sit. The park ranges from ~6,600 ft at the canyon floor below the rim to 9,105 ft at Rainbow Point at the south end of the park; the rim itself runs 8,000-9,000 ft. Rainbow Point and the southern viewpoints run 3-7°F colder than the HQRS reading year-round, and snowfall at Rainbow Point is materially higher than the HQRS station total. The below-rim canyon and the trails that drop into it (Navajo Loop, Queen's Garden, Peek-a-Boo) run notably warmer in summer than the rim reading. Treat these numbers as a rim-elevation proxy for the visitor experience. PREVIEW status. The NCEI pipeline has not yet wired BRCA into monthly_climate_normals.csv (only ACAD is in for now) and no manual selection row exists in weather_station_selections.csv. The five BRCA candidates in noaa_station_candidates.csv include USC00421008 (this station, the best fit), USW00023159 (Bryce Canyon Airport, 7,586 ft, no snow normal), and three more distant or higher-elevation alternatives. Final selection should be approved in data/manual/weather_station_selections.csv.
Access score
Formula: For each named park road, count it open if its typical operating window covers that month. Score = round((sum of weights of open roads / sum of all weights) x 100). Where a park has a partial winter access mode, the profile documents that assumption in its access notes.
Route weights at Bryce Canyon:
- Main Park Road (Highway 63): Year-round (temporary winter closures for plowing)
- Bryce Canyon Shuttle: Early April → mid-October
- Winter spur road closures: Closed to vehicles late autumn → spring
- Entry fees: Year-round entry
- Bryce Canyon Lodge: Early March → late November (varies by unit)
- Campgrounds: North year-round · Sunset April 14 → October 12
- Vehicle length restriction in the amphitheater: Mid-April → mid-October (shuttle season)
- Altitude and thunderstorm safety: Year-round · thunderstorms peak Jul-Aug
Editorial methodology, the route weights themselves are author-curated, sourced from data/processed/operations/road_windows.csv and the park's own access caveats below the score table.
Caveat: The score reflects wheeled-vehicle road access only. Backcountry, hiking, lodging, shuttle, and other service availability are not directly included unless the park profile states otherwise.
Why no combined score?
A combined "best month" number forces a weighting: how much do you care about crowds vs. weather vs. access? Those weights are personal. A photographer optimizing for golden light weights differently than a parent locked to school break weights differently than a winter visitor with a 4WD. We show the inputs and let you decide. Use the per-month grid above to navigate to a deeper page.
