My prediction for tomorrow's largest global warming rally in history: An embarrassingly large percentage of attendees will get cold and leave early

Hourly Weather Forecast for Sunday, Feb 17, 2013 - Washington, DC

[temperatures in the low 30s with winds close to 20 mph]

NWS Wind Chill Index

Join the #ForwardOnClimate Rally on 2/17! - Sierra Club

What: The largest climate rally in U.S. history.
When: February 17, 2013, Noon - 5:00 p.m. (please arrive by 11:30 a.m.)
Where: The National Mall in Washington, D.C.
...On Sunday, February 17, thousands of Americans will head to Washington, D.C. to make Forward on Climate the largest climate rally in history.

I'd love to see a picture of the crowd at noon vs the crowd at 5pm.