Sea level. Mean sea level (MSL) (abbreviated simply sea level) is an average level of the surface of one or more of Earth's oceans from which heights such as elevations may be measured.
Dates: September - October. Weather: Autumn in Wyoming is a delight. Many locations will see snow in mid-September, but it doesnât get to be real winter until late November. During October and November youâll discover a warm Indian Summer, with cool nights and beautiful changing colors. Early freezes in the fall are common.
Dates: September - November. Weather: Fall is beautiful in Yellowstone with crisp, cool air and the aspens glowing with a palette of oranges, yellows and reds. It is another great time to visit the Park. There is less traffic and the scenery dressed in all the fall colors is awe-inspiring.