I have just got back from a ride (the roads were finally dry). It was 4°C on my return - I wondered what the windchill would be at 60mph, off to the internet...
...there are charts!
http://www.norcalpgr.org/wind_chill_charts.html
So 4°C is about 39°F (call it 40°F) and the windchill at 60mph makes the temp feel like 25°F or about -4°C. I thought it was a bit chilly.
The only cold areas were my forehead (not sure I had all my helmet vents closed) and my toes. I use RST heated gloves - normally on the low setting but I upped it to the mid setting so my fingers were warm. (I should add that I have handguards fitted too).
Other gear: Zerofit base layers, Weise textile trousers, Wolf textile jacket (I recommend them all).