Because the speaker remains singularly focused on their beloved, “How Do I Love Thee?” doesn’t have a concrete setting. The only detail in the entire poem that might locate it in a particular setting comes in lines 5–6: 

     I love thee to the level of every day’s
     Most quiet need, by sun and candle-light.

The reference to candlelight indicates that the poem takes place at a time before the ready availability of artificial light. As such, the poem is likely set in the nineteenth century or sometime earlier, though we still don’t know where. Given the relative obscurity of the setting, it might make sense to locate the poem in a more abstract location that’s associated with the long European tradition of love poetry. In this tradition, poets have often presented love as something that exists beyond the normal confines of the everyday, profane world. Instead, love is a spiritual experience that more properly belongs to an abstract, metaphysical realm that is perfect, pure, and eternal. The speaker of this sonnet doesn’t explicitly invoke such a realm. However, they implicitly do so in lines 2–4:

     I love thee to the depth and breadth and height
     My soul can reach, when feeling out of sight
     For the ends of being and ideal grace.

Here, the speaker implies that their amorous feelings transcend the ordinary bounds of space and time and so “can reach” the realm where love properly dwells.