Reason for drawing water at unusual time John 4:5-8
New Living Translation (NLT)
5: Eventually he came to the Samaritan village of Sychar, near the field that Jacob gave to his son Joseph.
6: Jacob’s well was there; and Jesus, tired from the long walk, sat wearily beside the well about noontime.
7: Soon a Samaritan woman came to draw water, and Jesus said to her, “Please give me a drink.”
8: He was alone at the time because his disciples had gone into the village to buy some food.

So according to my water drawing knowledge, people used to draw water once in the day and once in the night.

Genesis 24:11
New Living Translation (NLT)
11: He made the camels kneel beside a well just outside the town. It was evening, and the women were coming out to draw water.

My knowledge is further reinforced by that fact that no one else in the village was with the Samaritan woman to draw water. It seems a bit too convenient for Jesus. Why was the woman drawing water at the middle of the day?
It wasn't just convenient: according to John (verse 4) Jesus "had to" (dei') pass through Samaria. It was not geographically necessary, as He could have (like most Jews did unless they were in a hurry) gone around Samaria. When John uses dei' he is referring to God's will. Jesus passed through Samaria with the intention of speaking with this woman.


  Jesus said to her, "Go, call your husband, and come here." The woman answered him, "I have no husband." Jesus said to her, "You are right in saying, 'I have no husband'; for you have had five husbands, and the one you now have is not your husband. What you have said is true." 
  (John 4:16-18)


She lived in a culture that followed strict laws concerning sexual purity, so it seems she would have been an outcast. Considering the Samaritans were rejected by Jews (John 4:9), she is an outcast among outcasts.