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Hey all! I'm a novice climber, having done only one climb this spring and one and a half this summer, but I'm looking to squeeze one more in before the end of the season. I haven't spent much time in the sierras at all (only moved here a couple years ago) and I was wondering when the snows really start to set in. I'm hoping to make another attempt on Agassiz from Bishop Pass over Labor Day weekend-- is that too late to safely climb without risking a snowstorm?

Thanks!

Labor Day weekend will very likely be a great time to hike in the Sierra.

Late summer and much of fall tend to be warm and dry seasons in California. The farther north you go, the sooner storms tend to hit, but September is prime Sierra time regardless. High elevations of the Sierra sometimes get snow in September or October, but snowpack development often waits until November or December. One exceptional year, things were pretty dry through January. Overnighting and tackling steep slopes can become riskier in October and beyond if you happen to want to go out when a storm arrives, soon after a storm, or if a slope remains snowy for the season. Nights can be at or below freezing again as we move through August and September.

I'm not sure if you already check weather.gov:. http://forecast.weather.gov/MapClick.php?lat=37.11159659800046&lon=-118.5309363779997#.V5UIdp9lDqA

As we move through September into fall and winter, reading the forecast discussion (from Las Vegas, Reno, Hanford, and Sacramento) becomes more important, especially beyond a few days out. Mammothweather.com has discussion as well. Learning to read clouds and weather while out becomes more useful as well.

I think September would be a great time to go up. I have done most of my climbing during September and October and found great conditions. Many of my friends have weddings and family vacations, the best trailheads get reserved up; and it is really tough to coordinate a weekend. The typical conditions I have found are bright blue skies, warm temperatures during the day, and cool nights. I have experienced an occasional short lived rain or thunder storm. The main issue with October I have found is that the days get quite short.

The only exception was last year, I went up to Middle Palisade in Late October. There was heavy snow the week before above 11,000 ft. and we received snow and hail during the trip. We made it to the top of the glacier, start of the final climb, through 4 ft. of snow. We thought walking out onto the glacier might be risky, to do the easy route. The rocks were crusted over with ice and we did not feel good climbing that; so we did not summit. Despite all this we still had great fun.

I climbed Agassiz 3 years ago in mid September and got stormed on. It started at 4pm. The next day dawned clear and sunny and the snow was 4" deep. Spectacular; I'll never forget it.