When answering this question, the best place to look in the novel for material will be between the moment when Huck arrives at the island after faking his death and the episode with the Grangerford family.
Nature plays its biggest part in the novel in this section, as Huck and Jim enjoy life for a time on the island, arranging a cozy shelter for themselves and staying dry in a cave.
The storms of the season continue to bring rain, thunder and lightening after Huck and Jim set off down the river. Huck remarks on these storms repeatedly in the narrative, describing his response to them and their beauty.
After this section of the novel, the narrative does not include as many references to nature or the seductive power nature has over Huck.