Look at the yearly chart of his monthly average. Ouch.

Via Gallup:

President Barack Obama wrapped up 2013 with an average 41% approval rating in December, unchanged from November. However, his monthly job approval declined steadily through most of 2013, including a three-percentage-point drop in March.

Obama started the year with approval ratings generally where they left off in 2012 — in the middle to upper 50s. These included consecutive days in early January at 56% — his highest three-day rating of 2013.