Strength of schedule is calculated from the opponents projected fantasy points allowed for the PK position. The best rating is +16 which gives the player the advantage against the defense and indicates an easy opponent, the worst rating is -16 which gives the defense the advantage and indicates a tough opponent.
The 49ers have been a little too efficient offensively so far this season giving him only 3 field goal attempts so far. Deeper leagues should stick with him but smaller leagues can begin to consider other options.
After 14 long years in Cleveland, Dawson joined the 49ers in 2013. The results were pretty danged good, with the 39-year-old tying a career-best with 36 made field goals. That production, and the 40+ extra points that came with it, merited a sixth-place finish among fantasy kickers in 2013, and there's little reason to think Dawson can't at least match that mark this year.