Racing

Leadville 100 Weather Guide

Weather conditions at the Leadville 100 high-altitude ultramarathon.

Run Window TeamApril 24, 20261 min read

The Leadville 100 at 10,000+ feet brings unique weather challenges.

Leadville Altitude Weather

The setting: Colorado mountains, starting at 10,200 feet, topping 12,600 feet.

What this means: Thin air + mountain weather = volatile conditions.

August in the Rockies

Typical pattern:

  • Cool/cold nights
  • Warming days
  • Afternoon thunderstorms possible
  • Temperature swings

Race Weather Progression

4am start: Cold. Wear layers.

Daytime climbs: Warming but altitude keeps it cooler than valleys.

Hope Pass (12,600ft): Cold, exposed, potential storms.

Night: Cold again, can be very cold.

Mandatory Gear Reasoning

Why Leadville requires:

  • Jacket
  • Headlamp
  • Emergency supplies

Answer: Mountain weather changes rapidly.

Storm Awareness

Afternoon thunderstorms: Common at altitude.

Above treeline: Lightning danger.

Race adjusts: But you must be prepared.


Leadville's altitude creates unique weather challenges. Cold nights, afternoon storms, prepare for everything.

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