Mount St. Helens · Climbers Bivouac 3,747 ft → summit 8,172 ft
Before you go
- NWS point forecast for the summit (opens in a new tab)
National Weather Service
- Avalanche forecast (winter) (opens in a new tab)
Northwest Avalanche Center
- Gifford Pinchot National Forest: current conditions (opens in a new tab)
Gifford Pinchot National Forest
- Roads and passes: 511Now (opens in a new tab)
511Now
This is an estimate. Check the National Weather Service point forecast (opens in a new tab) before you go.
Conditions change fast. Turn back if it doesn't feel right.
How this works
We read two National Weather Service forecasts: one for the area around the trailhead and one for the area around the summit. Each covers an area a few kilometers across, and NWS tells us that area’s average height.
Temperatures are estimated for the true heights. Between the two areas, the forecast itself says how fast it cools with height. We use that rate (kept between a mild inversion, 3 °C warmer per km up, and 9.8 °C cooler per km, the steepest normal cooling). When the two areas are less than 300 m apart in height, we use the standard rate of 6.5 °C per km (about 3.6 °F per 1,000 ft) instead:
rate = (trailhead area temp − summit area temp) ÷ (summit area height − trailhead area height)
summit ≈ summit area temp − rate × (summit height − summit area height)
Wind, gusts, the chance of rain or snow, sky cover, new snow, and the snow level are the NWS numbers for each area, shown as they are. There’s no honest simple rule for adjusting them. Snow levels are rounded to the nearest 100 ft (50 m).
Sources & last checked
- National Weather Service (api.weather.gov) (opens in a new tab)
Forecasts and alerts, read live by your browser; each forecast shows when it was issued
- USGS Elevation Point Query Service (3DEP) (opens in a new tab)
Summit and trailhead elevations
checked
- Northwest Avalanche Center (opens in a new tab)
Avalanche center links (links only)
checked
- Central Oregon Avalanche Center (opens in a new tab)
Avalanche center links (links only)
checked
Source: National Weather Service (api.weather.gov), USGS Elevation Point Query Service (3DEP), Northwest Avalanche Center, Central Oregon Avalanche Centerlast checked
Every source we use is on the Credits page.
About this tool
The weather at the trailhead is rarely the weather on top. This tool puts the National Weather Service forecast for a peak’s trailhead and its summit side by side for the next seven days: highs and lows, wind and gusts, the chance of rain or snow, and the snow level, the height where rain turns to snow.
NWS forecasts cover areas a few kilometers across, so the forecast “at the summit” is really for the area around it, which sits lower than the top. We show that height and estimate the summit temperature from the forecast’s own change in temperature with height. Everything else comes straight from the NWS, with the time it was issued.
It’s a planning aid, not a go or no-go call. Each peak links to the official NWS point forecast, the avalanche center that covers it in winter, and the land agency’s conditions page. Check them before you go.
Mount St. Helens starts from Climbers Bivouac at about 3,747 ft; the summit is about 8,172 ft (USGS Elevation Point Query Service (3DEP), checked 2026-09-29).