This morning, about 7:30, the sun warmed a roost about half a mile from where the bird counters sit. This site is along the cliffs, just above the lake. The Monarchs moved westward for the next hour at about 50/minute. Too high to tag.
On Sept 5, after a cool morning at Hawk Cliff, the clouds broke and the sun came out at about 1:00. The hawk counters reported to me that at that time 100 Monarchs/minute passed over their heads. That's 6000 per hour for the next 2 hours!!!!
I wasn't witness to this, but do trust these veteran hawk watchers.