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