Contradiction with James 5:17
This verse states that Elijah prayed earnestly for it not to rain, and it did not rain for three and a half years, which may seem contradictory if 1 Kings 18:2 implies the return of rain after a different period.
James 5:17: Elias was a man subject to like passions as we are, and he prayed earnestly that it might not rain: and it rained not on the earth by the space of three years and six months. [subject...: of the same nature, that is, a fellow mortal] [earnestly: or, in his prayer]
Contradiction with 1 Kings 17:1
This verse declares that there will be no dew or rain for several years at Elijah's word, possibly contradicting how and when the drought would end according to 1 Kings 18:2.
1 Kings 17:1: And Elijah the Tishbite, [who was] of the inhabitants of Gilead, said unto Ahab, [As] the LORD God of Israel liveth, before whom I stand, there shall not be dew nor rain these years, but according to my word. [Elijah: Heb. Elijahu: Gr. Elias]