Read these lines from the poem "Fern Hill." All the sun long it was running, it was lovely, the hay Fields high as the house, the tunes from the chimneys, it was air And playing, lovely and watery And fire green as grass. What does the speaker mean when he says, "All the sun long it was running"? He was exhausted by the end of the summer. The summer season made the sunny days longer. He worked all day and only got to explore the farm at night. The sunny weather allowed him to play outside all day.

The sunny weather allowed him to play outside all day.

Explanation:

Dylan Thomas' poem "Fern Hill" is a reminiscing of the poet's childhood days at his aunt's farm at Fernhill. The poem gives a detailed and idyllic description of how the place looked and how he used to enjoy himself.

The lines given in the question are from the third stanza of the poem where he described in an expanded detail, the idyllic, Edenlike setting of the farm. He used allegory and even metaphors to compare the from to that of the Garden of Eden. When he said "All the sun long it was running", he meant that thew god, sunny weather of the place allowed him to be outdoors all day. He could play all day and be around the nature, without any disturbance.