This season, the speediest and most elusive of the planets leaves the morning sky, passes behind the Sun, and reappears in the evening. At the beginning of April, Mercury is barely visible very low in the east just before dawn and is almost at greatest western elongation, which occurs on April 11. That's when its angular separation from the Sun as seen from Earth is as wide as it can get (nearly 28 degrees). Following maximum elongation, Mercury retreats into the Sun's glow and passes behind our star on May 21 (superior conjunction). It doesn't re-emerge from the glow until early June, when you might be able to spot it very low in the west-northwest after sunset, very near Mars at mid-month (as little as a fifth-of-a-degree away on the 17th). Mercury reaches greatest eastern elongation on June 23, when it sets almost 90 minutes after the Sun.
The razor-thin waning crescent Moon is very near Mercury on the mornings of April 2 and May 2, but these encounters are very close to the Sun and difficult to see. The Moon's pass on June 4 is as difficult, occurring in the early evening sky, when the Moon is a thin, day-old waxing crescent.