Finding the conditions in Arvada might be tough if only because there isn't an official NWS station there. I don't know if it helps, but you can find the official conditions in Denver on that date and maybe glean some knowledge from it.
If you go to the NWS Boulder Office climate page here:
http://www.crh.noaa.gov/bou/?n=climo . Scroll down just a bit to "Denver Monthly Weather Summaries" and select the month and year and you will get a day by day log for that month.
Hope that helps.
Tony