Mercury can be seen in early August near the western horizon just after sunset. Maximum eastern elongation is August 7th, however the angle of the ecliptic keeps the planet pretty low in the sky.
Venus reaches its maximum (eastern) elongation on August 20, so Venus is high in the evening sky at dusk throughout the month.
Mars moves slowly toward the western horizon (at dusk) during August. It will be near Venus during much of the month.
Jupiter is near opposition, so rises in the East only a bit after dark. Europa and its shadow transit on the morning of August 3, on the evening of August 20, and around midnight on August 27-28. Ganymede, Io and Io's shadow transit the morning of August 6; Io and its shadow transit several times (8/7, 8/13, 8/15, 8/22, 8/23, 8/29 and 8/30).
Saturn starts the month above (east of) Venus, but gets lower and lower in the West each evening. By month's end it will be only a few degrees above the horizon at dark. Saturn will be lost in the Sun's glare for a couple of months, then re-appears in the early morning in late October. During August, Titan will be just off the SE limb of the planet on August 4th and August 20th.
Outer Planets. Uranus and Neptune. Uranus is very close to Jupiter. Neptune rises in the East about 8 pm.
Pluto is a bit past opposition, so rises a bit before sunset. It's in a very busy part of the Milky Way, so is quite difficult to find.
Comet 10P/Tempel 2 is around magnitude 8-9 and is visible in Cetus between around 1 am and dawn throughout August.
Additional info about these and other bright comets may be obtained here.
The Alpha Capriconids meteor shower peaks on August 1st. It's a relatively minor shower, but could provide a few good meteors prior to Moon-rise. The Perseids are almost always a good show, and peak the night of August 12-13. The Moon will set early, so this is a good year to observe the shower if the weather is good.
The Summer Milky Way is high in the sky at nightfall. If the southern horizon is clear, look for numerous nebulae in Saggitarius (M8, M17, M20, M16). Many can be seen with binoculars. There are also numerous open and globular clusters that can be viewed with binoculars or a modest telescope. Scorpius is at the zenith at nightfall and makes for a great wide-angle photo opportunity. Same for Saggitarius and Cygnus. So much to observe/image, so little time.
