The best page to find current conditions on is this one here:
http://www.rap.ucar.edu/weather/surface/
This is the page I use every day as a meteorologist and would recommend all of you to take a look at in the morning before you head to your race. It shows wind barbs, temperature, dew point, weather reported, and altimeter, but if you select the Java large version below in blue, you can zoom in on any area, display more or fewer sites, and display only the information you want to see.
I am also a fan of WeatherBug as they have thousands of weather stations located all across the country. To make good use of this, just go to:
http://weather.weatherbug.com/
Once you are in this site, just type the city or zip code that the race is located in and you can see what the current conditions are at a station possibly right down the street. I’ve been working with WeatherBug for years and really like their company.