Zion National Park is one of the most visited parks in the United States — and one where timing your visit makes an enormous difference. Summer heat and monsoon storms sharply reduce comfort, while October, November, and December deliver some of the best weather scores in the entire national park system. Using Perfect Weather Index (PWI) scores calculated from daily National Weather Service forecast data, this page shows exactly when conditions are most comfortable for hiking the Narrows, Angels Landing, and Zion's iconic canyon trails.
Current Perfect Weather Index scores for the next 7 days at Zion National Park. Higher scores indicate more comfortable outdoor conditions. Updated daily using National Weather Service forecast data.
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How to use this: Days with higher scores are generally better for hiking and outdoor activities, with more comfortable temperatures, lighter winds, and fewer weather impacts. → View official National Weather Service forecast for Zion
October is the single best month to visit Zion National Park based on Perfect Weather Index scores, with December, November, and April also delivering exceptional conditions.
Based on Perfect Weather Index (PWI) data from Zion Canyon (elevation ~3,900 ft) — drawing on NWS forecast records and historical climate normals — Zion shows a pattern that surprises many visitors: fall and winter score highest while summer — the most visited season — delivers the lowest comfort scores due to intense heat and monsoon humidity. December scores 82% PWI with 5 perfect days, outperforming every summer month. These seasonal patterns are consistent with long-term climate data for the Colorado Plateau.
Raw monthly totals were normalized into monthly PWI scores (percent of possible points) and paired with the number of rare Perfect 10 days.
Monthly PWI scores reflect the percentage of possible comfort points earned at Zion Canyon across all days in each month, derived from National Weather Service forecast data and consistent with long-term climate normals for the Zion Canyon area. Perfect 10 days are days scoring a full 10 out of 10 on the PWI scale.
| Month | Monthly PWI Score | Perfect 10 Days | What It Means | Verdict |
|---|---|---|---|---|
| January | ~72% | 0 | Cool, quiet, some cold mornings | Good |
| February | ~79% | 3 | Improving temps, still low crowds | Very Good |
| March | ~75% | 0 | Variable spring weather | Very Good |
| April | ~82% | 3 | Excellent balance of warmth & comfort | Excellent |
| May | ~77% | 0 | Warmer days, rising heat | Very Good |
| June | ~70% | 0 | Hot afternoons begin | Good |
| July | ~69% | 0 | Heat + monsoon storms | Fair |
| August | ~65% | 0 | Hottest, most humid period | Caution |
| September | ~73% | 0 | Gradual cooling | Good |
| October ⭐ | ~83% | 4 | Peak conditions, very reliable | Excellent |
| November | ~81% | 3 | Cool, crisp, fewer people | Excellent |
| December | ~82% | 5 | Surprisingly excellent winter weather | Excellent |
PWI scores based on NWS forecast data at Zion Canyon (~3,900 ft). Observation Point and higher-elevation trails will be cooler; the Narrows has its own hazard profile independent of temperature.
Average monthly visitor counts at Zion National Park (2019–2023 average, source: NPS). Note the striking mismatch between visitation and weather comfort — summer months draw the most visitors but score lowest on the PWI, while October through December deliver peak comfort with far fewer crowds.
| Month | % of Annual Visitors | Avg Visitors | Crowd Level |
|---|---|---|---|
| January | 3% | 130,503 | Low |
| February | 3% | 139,039 | Low |
| March | 8% | 343,141 | Moderate |
| April | 8% | 364,993 | Moderate |
| May | 11% | 474,301 | High |
| June | 12% | 556,426 | Peak |
| July | 12% | 554,096 | Peak |
| August | 10% | 469,603 | High |
| September | 11% | 486,413 | High |
| October | 11% | 484,521 | High |
| November | 6% | 286,923 | Moderate |
| December | 4% | 200,044 | Low |
Source: National Park Service visitor use statistics, 2019–2023 average.
October is Zion's top-scoring month at 83% PWI with 4 perfect days. Summer heat has fully dissipated, monsoon storms have ended, and the canyon walls glow with fall color. Temperatures are ideal for all of Zion's major hikes — the Narrows, Angels Landing, and the Zion Traverse all become notably more comfortable without summer heat. October still draws significant crowds (11% of annual visitors) but the experience is dramatically better than summer.
December scored 82% PWI with 5 perfect days — the most perfect days of any month and higher than every summer month. Winter at Zion's 3,900-foot canyon elevation is mild compared to most national parks. Daytime temperatures typically reach the mid-50s°F (13°C) with clear, crisp skies. Crowds drop significantly — only 4% of annual visitors come in December — making it one of the best months for experiencing Zion without the congestion that defines spring and summer visits.
November (81% PWI, 3 perfect days) and April (82% PWI, 3 perfect days) both deliver excellent conditions. November sees crowds ease quickly after October's peak, with cool mornings and comfortable afternoons. April marks the beginning of warm weather with temperatures ideal for hiking before summer heat arrives. Both months are among Zion's best for combining strong weather with manageable visitor numbers.
February scored 79% PWI with 3 perfect days — notably higher than June or July. Winter light in the canyon is exceptional for photography, crowds are at their lowest point of the year, and popular trails like Angels Landing and the Narrows are accessible on most days. March brings more variable weather as spring patterns develop but remains comfortable. Both months reward visitors willing to pack layers for cool mornings.
Summer is Zion's most popular season but its worst for weather comfort. June begins the heat buildup, July brings both peak temperatures and the start of the North American Monsoon — afternoon thunderstorms that can flood the Narrows with little warning and make slot canyon hiking dangerous. August is the lowest-scoring month at 65% PWI, combining intense heat with the highest humidity of the year. Flash flood risk in the Narrows is highest from July through mid-September. Always check conditions before entering slot canyons during this period.
Zion's weather varies by location and elevation. The PWI scores on this page reflect Zion Canyon at approximately 3,900 feet — conditions at higher elevations like the East Mesa or Observation Point trail differ significantly, and the Narrows has its own unique hazard profile regardless of season.
The Narrows: Flash flood risk is the primary weather hazard for the Narrows hike. Thunderstorms upstream — sometimes miles away and invisible from the canyon — can send walls of water through the slot canyon with little warning. The NPS posts Narrows conditions daily and will close the hike when flood risk is elevated. July through mid-September is the highest-risk period. Always check conditions before entering. Outside of monsoon season, the Narrows is accessible and spectacular in every month that temperatures are above freezing at the canyon floor.
What is the best time to visit Zion National Park?
October delivers the highest PWI score — 83% with 4 perfect days — and still has manageable crowds compared to summer. December is the sleeper pick: 82% PWI with 5 perfect days and only 4% of annual visitors. If spring is more convenient, April scores 82% PWI with 3 perfect days before the summer heat arrives. The one month to avoid for comfort is August — the hottest, most humid month of the year with the lowest PWI scores.
When is it safe to hike the Narrows at Zion?
The Narrows is safest and most reliable from October through June. July through mid-September is the monsoon season, when upstream thunderstorms can trigger flash floods in the slot canyon with little warning — the NPS will close the Narrows when flood risk is elevated. Even outside monsoon season, water levels fluctuate based on snowmelt and recent rain. Always check the NPS Narrows conditions page on the day of your hike before entering. Winter hiking is possible when temperatures are above freezing but requires a drysuit rental for the coldest months.
Do you need a permit to hike Angels Landing?
Yes — Angels Landing requires a permit year-round. Permits are distributed by lottery: a seasonal lottery opens several months in advance, and a smaller day-before lottery opens for each hiking day. Competition is high during peak season (March through October). The hike involves exposed chain sections with significant drop-offs and is not recommended for those with a fear of heights regardless of permit status. November through February sees lower permit competition and more comfortable temperatures for the climb.
How hot does Zion get in summer?
Zion Canyon regularly reaches 100–105°F (38–41°C) on the hottest summer days. The canyon walls trap heat and radiate it through the afternoon, making midday conditions significantly more intense than the official temperature reading suggests. The combination of heat and humidity during the July–August monsoon season makes August the lowest-scoring month of the year on the PWI. If you visit in summer, plan all strenuous hiking before 8am and stick to shaded riverside trails during midday hours.
What is the best time to visit Zion for international visitors?
October is the clear first choice — peak weather, fall color in the canyon, and noticeably less congestion than summer. November and December are excellent alternatives with even fewer crowds. Zion is easily reached from Las Vegas (about 2.5 hours by car) and is a natural anchor for a Utah national parks road trip combining Bryce Canyon, Capitol Reef, Arches, and Canyonlands. Many international visitors fly into Las Vegas and drive the scenic Utah Highway 9 through the park.
What is the Perfect Weather Index?
The Perfect Weather Index (PWI) is a daily comfort score from 1–10 calculated from National Weather Service forecast data. It combines temperature, sunshine, humidity, wind, and precipitation into a single rating. A score of 8 or higher means genuinely excellent outdoor conditions. Scores below 4 reflect cold, storms, or other conditions that significantly limit outdoor comfort. Learn more about how the PWI works →