my average was around 19+mph. i figured this was doing alright for the conditions: lots of small towns and traffic, cold, wind, rain, and riding solo. i was unprepared and only had shorts and a short sleeve jersey. the only way i could stay warm was riding hard between towns. (which also picked up my in town average)

edit:
i cant recall my exact average, but i know i was on the bike a little over 4 hours. i remember this because i couldn't read my computer (driving rain) and when i got to where i was going i wiped it off and couldn't believe the ride time. it felt like two days...