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Summit

Guinn Mountain

Colorado

About

Guinn Mountain is a summit of 11,227 feet in the Boulder Ranger District of the Arapaho and Roosevelt National Forests in Colorado, about 3.7 miles from the town of Eldora. Summer is the most comfortable time to go. Typical averages from a nearby weather station show July highs around 68°F with lows near 43°F, and temperatures on the summit run cooler than that station. September is milder still, with highs around 59°F. The Jenny Creek Trail starts just 0.3 miles away, and the Needle Eye Bypass Trail is about 0.7 miles off. Eldora, a climbing area, is roughly 2 miles away, and Rainbow Lakes Campground sits about 6 miles from the summit.

Summit Facts

Summit elevation

11,227 ft

Elevation from USGS 3D Elevation Program terrain data (about 10 m resolution).

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Location

Guinn Mountain

Colorado

Name and location: U.S. Geological Survey, Geographic Names Information System (GNIS). Elevation: USGS 3D Elevation Program. View the GNIS record.

Facts about this place

When to go

Best time to go: Jun–Aug. The mildest months here, with typical highs of 62–68°F and lows of 36–43°F.

Typical monthly averages (not a forecast) from the Boulder 14 W, CO weather station, 8.8 mi away. High / low in °F.

  1. Jan29° high12° low
  2. Feb28° high11° low
  3. Mar36° high17° low
  4. Apr40° high22° low
  5. May50° high29° low
  6. Jun62° high36° low
  7. Jul68° high43° low
  8. Aug66° high41° low
  9. Sep59° high34° low
  10. Oct47° high26° low
  11. Nov35° high19° low
  12. Dec28° high12° low

The station sits about 1,400 ft lower than this spot, so expect it to run cooler up here.

Source: NOAA NCEI U.S. Climate Normals 1991–2020

Where it is

Nearest town
Eldora, Colorado · 3.7 mi

Source: USFS EDW boundaries; USGS GNIS populated places

Conditions

Active alerts for Boulder Ranger District as of Oct 9, 2026:

Source: USFS forest alerts

Nearby

Source: Roamze catalog (indexable pages within 10 miles, PostGIS distance)

Is Guinn Mountain open right now?

Alert in the area

The Forest Service lists 3 alerts for Arapaho and Roosevelt National Forests.

As of · Source: USFS · Arapaho and Roosevelt National Forests. Agencies don't list every closure — check before you go.

Best time to visit Guinn Mountain

Best months: June and September. Best months have typical highs of 55–85 °F, lows of 30 °F or warmer (32 °F where the station doesn't record snow), at most one snowy day and no more than 12 wet days.

  1. Jan

    29° / 12°

    15 wet

  2. Feb

    28° / 11°

    16 wet

  3. Mar

    36° / 17°

    16 wet

  4. Apr

    40° / 22°

    17 wet

  5. May

    50° / 29°

    16 wet

  6. Jun

    62° / 36°

    12 wet

  7. Jul

    68° / 43°

    14 wet

  8. Aug

    66° / 41°

    13 wet

  9. Sep

    59° / 34°

    10 wet

  10. Oct

    47° / 26°

    10 wet

  11. Nov

    35° / 19°

    12 wet

  12. Dec

    28° / 12°

    15 wet

Typical high / low (°F) and days with rain or snow, 1991–2020. Measured at Boulder 14 W, CO, 8.8 mi away at 9,828 ft. The station sits about 1,400 ft lower than this place, so expect it a little cooler here. This station doesn't record snowfall. Source: NOAA NCEI U.S. Climate Normals 1991–2020.