Mount Rainier creates its own weather. The 14,411-foot peak intercepts Pacific moisture moving east from the coast, making Paradise (5,400 ft, south side) one of the snowiest places on Earth — it averages 140+ inches of precipitation per year and held the world snowfall record (93.5 feet in one season) until 1999. The best weather window for hiking is late July through mid-September, with August being the most reliably clear month. Mornings are almost always better than afternoons. Here's exactly what to expect by month and elevation.
Mount Rainier Weather by Month
| Month | Ashford Hi/Lo | Paradise Hi/Lo | Conditions | Trail Status |
|---|---|---|---|---|
| January | 40/30°F | 28/20°F | Heavy snowfall; storms frequent; road to Paradise sometimes closed | Snowshoe/ski only above 3,000 ft |
| February | 43/31°F | 29/21°F | Peak snow depth at Paradise; cold and wet; occasional clear days | Snowshoe season; Longmire loop passable |
| March | 48/34°F | 33/24°F | Still winter conditions at elevation; increasing daylight; storms continue | Snowshoeing; lower forest trails clear first |
| April | 54/38°F | 38/28°F | Snow melting at lower elevations; mud season at mid-elevations; can be pleasant | Longmire area trails open; Paradise still deep snow |
| May | 61/43°F | 44/33°F | Lower trails clear; upper elevations still snowy; spring wildflowers below 3,000 ft | Trail of the Shadows, Longmire open; Paradise trails mostly snow |
| June | 67/47°F | 50/38°F | Transition month; clearing rapidly; Sunrise road usually still closed; waterfalls at peak flow | Lower trails clear; upper Paradise still snow-covered |
| July | 72/51°F | 57/41°F | Clear mornings, afternoon clouds; wildflowers beginning at Paradise; snow on upper Skyline | Most trails open; upper Skyline may have snow patches into mid-July |
| August | 74/52°F | 60/44°F | Best weather month; peak wildflowers; sunny mornings; afternoon clouds common; driest period | All trails clear; maximum access; peak crowds |
| September | 68/47°F | 55/40°F | Excellent early season; fall color begins; Sunrise closes mid-month; first alpine snow possible | All trails clear early; Sunrise closes ~Sept 15; some upper closures late Sept |
| October | 57/40°F | 43/32°F | Fall colors at Ohanapecosh; early storms at elevation; snow likely above 5,000 ft by month end | Lower trails open; upper Paradise increasingly snow-covered |
| November | 46/35°F | 32/23°F | Winter arriving; snowshoeing season opens at Paradise; storms intensify | Snowshoe season begins; summer trails closed |
| December | 41/32°F | 29/20°F | Full winter; heavy snow; road to Paradise may close; Paradise Inn closed | Snowshoe/ski; avalanche risk at high elevation |
Data based on NPS climate records and NOAA historic averages for the Ashford/Nisqually corridor and Paradise SNOTEL station. Individual years vary significantly.
The Daily Pattern: When Is Mount Rainier Most Clear?
The single most useful weather insight for planning a Rainier hike: mornings are almost always better than afternoons. The typical summer day follows this pattern:
- 6–9am: Usually clear or partly cloudy. Rainier's summit visible on most August days. Best photography window. Parking lots not yet full.
- 9am–noon: Often still clear but clouds beginning to build on the summit. Upper mountain typically visible.
- Noon–2pm: Clouds accumulating. Summit cap (lenticular cloud) forming. Upper trails still clear.
- 2–5pm: Afternoon clouds or brief showers common, especially on the south (Paradise) side. Above-treeline hikers should start descending.
- Evening: Can clear again after 6pm — evening light on Rainier is spectacular when clouds lift.
The rule for above-treeline hiking: be at or below treeline by 2pm if there's any thunder risk. Check the NPS forecast at nps.gov/mora the evening before — they maintain a park-specific outlook.
Paradise vs Sunrise: Weather Differences
The two sides of the mountain have meaningfully different climates. Understanding why helps set expectations:
- Paradise (south/southwest facing) sits directly in the path of prevailing Pacific weather systems moving inland from the coast. It intercepts storm moisture first, making it one of the wettest high-altitude locations in the US. Even on clear summer days, afternoon clouds develop earlier and more reliably here. Annual snowfall averages 643 inches (53 feet).
- Sunrise (northeast facing) sits in a partial rain shadow behind Rainier's main mass. Storms arriving from the southwest lose a significant portion of their moisture on the south and west faces before reaching the east side. Sunrise sees roughly half the annual precipitation of Paradise and holds afternoon sun noticeably longer. This is why Sunrise, despite being 1,000 feet higher, often has a drier feel than Paradise.
Practical implication: if the Paradise webcam shows heavy cloud cover by 10am, check the Sunrise webcam — it may be clear. The east-side weather often diverges sharply from the south side, especially in the transition seasons.
Best and Worst Times to Visit
Best Weather Windows
- Late July – mid-August: Peak season for a reason. Wildflowers at maximum, most reliable sun, all trails open. Tradeoff: maximum crowds. Arrive before 8am at Paradise.
- Early September (first two weeks): Arguably the best overall window — clear weather, dramatically fewer crowds (school starts), huckleberries ripe, fall color just beginning. Sunrise closes around September 15, so visit that area first.
- Weekday visits any time in summer: Tuesday–Thursday sees 40–50% less traffic than weekends. Same weather, half the people.
When to Lower Expectations
- June: Upper trails still snowy, Sunrise not yet open, and weather is highly variable. Lower trails (Grove of the Patriarchs, Trail of the Shadows) are excellent; don't count on seeing the Skyline Trail clear.
- October: Beautiful fall color at Ohanapecosh, but upper elevations can get snow at any point. Good if you're flexible; risky if you're committed to a specific high-elevation hike.
- Any Sunday after a Saturday weather window: When Saturday is sunny, Sunday crowds at Paradise are catastrophic. If weather is good two days in a row, go Saturday and arrive very early.
What to Pack for Rainier Weather
The essential rule: dress for 20°F colder than the Ashford temperature, and assume rain above treeline regardless of the morning forecast. See the beginner hiking tips guide for the full layering system. The key items:
- Waterproof shell: Non-negotiable above treeline any month. Afternoon showers can appear within 15 minutes on a clear-looking day.
- Fleece or synthetic mid-layer: Paradise at 5,400 ft can be 25–30°F colder than Ashford. You'll use this at Panorama Point even in August.
- Sunscreen + sunglasses: UV intensity is significantly higher at elevation. Snow reflection amplifies it. Easy to underestimate on hazy days.
- Microspikes (June/early July): If hiking the upper Skyline Trail or any route above 5,500 ft before mid-July, microspikes provide much better traction than trail shoes on packed snow.
- Extra water: At higher altitudes on warm days, dehydration happens faster than expected. 2L minimum per person per half-day.
How to Check Current Conditions
- NPS Trail Conditions: nps.gov/mora/trail-conditions — updated regularly, including snow closures
- NPS Webcam (Paradise): Check whether the summit is visible right now before driving out
- NPS Park-Specific Forecast: nps.gov/mora/weather — separate forecasts for Longmire, Paradise, and Sunrise
- NOAA Mountain Forecast: More granular elevation-based forecasts for the Cascade range
More planning resources: Paradise vs Sunrise comparison · July conditions guide · August conditions guide · hiking tips for first-timers · 15 best day hikes
