Over the past 10 years, Western States 100 runners have faced temperatures ranging from 14\u00b0C (57\u00b0F) on cooler years to 27\u00b0C (81\u00b0F) in warmer editions. The median temperature of 23\u00b0C (73\u00b0F) puts this race in the challenging category for running conditions.
Wind speeds average 12 km/h during race hours, with peak gusts reaching 20 km/h in challenging years. Humidity sits around 27%, and there is a 10% chance of rain on race day.
These conditions translate to an estimated pace impact of +7.2% compared to ideal running conditions. For a 4-hour marathoner, that means roughly 17 minutes slower than a perfect-weather day.