Is there a rough formula that can be used for determining the temperature/conditions in the Huntington Ravine gullies and Alpine Garden, when knowing the summit conditions?

I went up Odell's on 01/21/2013, and would like to figure out what the temp was.

The following were the Mt. Wash conditions at the time:
Date: 01/21/2013
Time: 08:55am
Wind: W 66 G 75
Air: -15F
Dwpt: -15
Relative Humidity: 100%
Wind Chill: -56F