There is nothing in Scripture which states definitively the time of year or season in which Jesus was baptized. Any answer is conjecture. Nevertheless, the event is important and it is reasonable to assume there would be some significance or historical relevance to this date. Other major events in The Gospel occurred on a special day:
- The crucifixion happened at the time of the Passover and Unleavened Bread.
- The resurrection occurred on the day of First Fruits.
- The initial outpouring of the Holy Spirit occurred on the Feast of Weeks.
Given that other key events coincide with special dates it is reasonable to expect this would be true of the baptism and 40-days of fasting.
While there is no direct mention of the season, the text offers two clues which make certain dates less likely. The first is in the others who came to John:
But when he saw the Pharisees and Sadducees, coming… (Matthew 3:7) 1
Pharisees were those who were committed to obeying the Law. The Law required men to be present in Jerusalem at certain times of the year:
Three times a year all your males shall appear before the LORD your God in the place which He chooses: at the Feast of Unleavened Bread, at the Feast of Weeks, and at the Feast of Tabernacles… (Deuteronomy 16:16)
It is unlikely a Pharisee (or Sadducee) would violate the Law in order to question John; instead they would bring their questions when there was no conflict with the Law. This makes the times immediately before and after the Feasts less likely.
The second textual clue is similar:
Then Jesus came from Galilee to John to be baptized by him. (Matthew 3:13)
Jesus was coming from Galilee, not from Jerusalem. While there is no reason to impose a strict requirement that Jesus would be following the Law about being in Jerusalem for the Feasts, it is unlikely that the initiation of His public ministry would start with an event that (potentially) conflicted with the Law and so the emphasis is on a starting point of Galilee.
Matthew, Mark, and Luke all state the length of time Jesus spent in the wilderness, was 40-days. A connection to the calendar can be found using the 40-day period:
In the six hundredth year of Noah’s life, in the second month, the seventeenth day of the month, on that day all the fountains of the great deep were broken up, and the windows of heaven were opened. And the rain was on the earth forty days and forty nights. (Genesis 7:11-12)
In addition to the 40-days following, there are several parallels between this event and Jesus' baptism: water, the heavens above being opened, something from above coming down to the earth are all found in the baptism:
When He had been baptized, Jesus came up immediately from the water; and behold, the heavens were opened to Him, and He saw the Spirit of God descending like a dove and alighting upon Him. (Matthew 3:16)
In both cases there was an initial event followed by a 40-day period. According to the Scriptures God initiated the restoration of the earth with a 40-day period of rain in the life of Noah and the restoration of mankind with a 40-day period in the life of Jesus. Placing the baptism on the seventeenth day of the second month of the year connects that to Noah and the Flood.
In addition this date can be connected to the annual calendar:
”Speak to the children of Israel, saying: ‘If anyone of you or your posterity is unclean because a corpse, or is far away on a journey, he may still keep the LORD’s Passover. On the fourteenth day of the second month, at twilight, they may keep it…” (Numbers 9:10-11)
The second Passover date was the fourteenth day of the second month and the seventeenth day would correspond to crossing the Red Sea and entering the wilderness (a month after the Passover in Egypt). So placing the baptism on the seventeenth day of the second month also connects the baptism with the annual calendar when the second month Passover is included.
Additionally there is a connection with the ability to observe the Passover in the second month and the crucifixion of Jesus:
When Joseph had taken the body, he wrapped it in a clean linen cloth. (Matthew 27:59)
Those that buried Jesus could observe the Passover in the second month.
Given these facts, it is a reasonable conjecture to place the baptism as taking place on the seventeenth day of the second month. This means that Jesus could observe the Passover and Unleavened Bread in Jerusalem with His family as was their custom (Luke 2:41).2 Then after the date of second month Passover, Jesus left Galilee, went to the Jordan, and was was baptized on the seventeenth day of the second month.
One objection to this is that the Feast of Weeks would fall during the 40-days Jesus was in the wilderness and He would not be in attendance in Jerusalem, as required by the Law. This could be resolved on the basis that He was led by the Holy Spirit and was exempted. Another possibility is that Jesus actually went to Mount Sinai and observed the Feast of Weeks at the location Moses received the Law and broke the first set of tablets. Again this is conjecture, but it would allow for a complete connection with the Passover, Unleavened Bread, and Feast of Weeks at the beginning of the Gospel and the death, resurrection, and initial out pouring of the Holy Spirit at the beginning of The Church.
1. All Scripture is New King James Version
2. Additional conjecture: it is possible Jesus and His family were "unclean" due a death in the family and unable to observe the Passover in Jerusalem. For example, if Joseph died, his burial would make the household unclean. In that case, Jesus began His public ministry the year his earthly father died.