237. How long was the drought that was caused by Elijah's prayers?

An unspecified number of years.

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. 1 Kings 17:1

Three and a half years.

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. James 5:17

But I tell you of a truth, many widows were in Israel in the days of Elias, when the heaven was shut up three years and six months, when great famine was throughout all the land; Luke 4:25

Less than three years.

And it came to pass after many days, that the word of the LORD came to Elijah in the third year, saying, Go, shew thyself unto Ahab; and I will send rain upon the earth. 1 Kings 18:1

And it came to pass in the mean while, that the heaven was black with clouds and wind, and there was a great rain. 1 Kings 18:45