A week after perihelion, Comet C/2007 W1 Boattini should now be visible in the dawn sky by observers in the Northern Hemisphere. Preliminary results on Seiichi Yoshida's website indicate that it's now roughly magnitude 5.5 — still near its peak brightness.
On July 4th, Comet Boattini is just 6° above the eastern horizon 90 minutes before sunrise at latitude 40° north. That's too low for easy viewing, and the sky is already beginning to get bright even then. But the comet appears roughly 2° higher on each succeeding morning, and the Moon doesn't start to interfere until July 16th. Meanwhile, the comet is likely to fade as shown on Yoshida's website, becoming a faint telescopic target by August.
So early July is the best time for northerners to see this comet — assuming that your're fanatical enough to get up at 3 or 4 a.m. Few people are likely to see the comet without optical aid, but it should be pretty easy to spot through binoculars as long as your light pollution isn't too bad. Click here to download a detailed chart. We eagerly await our first post-perihelion reader reports.