That the lottery is not an event of jubilance and excitement is ironically suggested by the date:  June 27 is a sunny, pleasant day in which things appear tranquil and peaceful set against the brutality of what will happen.  This date is also near the summer solstice, a time when many ancient people had their prehistoric rituals. That the lottery is such a old ritual is suggested in the first paragraph of Shirley Jackson's story:

...the whole lottery took less than two hours, so it could begin at ten o'clock in the morning and still be through in time to allow the villagers to get home for noon dinner.The children talk and act normally as they break into "boisterous play," but, oddly, they fill their pockets with stones from a large pile; Bobby Martin select the "smoothest and roundest stones" as though he has practiced doing something with these stones before.

In a case of dramatic irony, when Bobby is called by his mother to stand with his family, he has to be called four or five times because he wants to run, "laughing," back to the pile of stones.

Of course, the introduction into the narrative of "the black box" that is old and splintered badly on one side seems foreboding as the villagers "kept their distance." Then, when Mr. Summers asks for help, there is "a hesitation" before two men come forward.  Jackson also writes that "so much of the ritual had been forgotten or discarded"; these line suggests something mysterious, something that is not typical, some ritual.

There is "a great deal of fussing" before the ritual begins.  Then a signing-in, a "ritual salute," and Mr. Summers acts "very proper and important as he talked...."  At this point the reader certainly wonders what type of ritual will occur.

When Mrs. Hutchinson arrives, she talks nervously, then taps Mrs. Delacroix "on the arm as a farewell" and makes her way through the crowd.  "A sudden hush" falls on the crowd as Mr. Summers clears his throat and looks at the list.  The people "grinned at one another humorlessly and nervously."  Again, there are suggests of something ominous to come.

In contrast to all the foreboding elements, the events of the story are related in such a matter-of-fact and objective way that is clearly ironic when considered against the purpose of the story to elicit much emotion and to lead the reader to question the morality of what occurs.

In "The Lottery," the reactions of the characters show irony.  For example, when Bill Hutchinson draws the black spotted paper, Tessie is incredibly upset and tries to argue that her daughter and son-in-law should also have to draw with the family.  On the first reading, a reader would be very confused by Tessie's reaction because lotteries are meant to win the lucky person a prize.  So, if Tessie's family were meant to get a prize, why would she be trying to pass off the good fortune to other family members?  So this ironic event is a clue that the lottery will "win" the drawer something other than a prize; the outcome of the lottery will not be beneficial.