In chapter 5 of The Great Gatsby, what does the rain signify?

In preparation for this meeting with Daisy, Gatsby has attempted to create the perfect environment. He is a master of controlling the world around him and has obtained nearly everything he has ever wanted through his industrious labor and insights. One thing has eluded him thus far: Daisy. On this day, he dresses to impress and makes sure that the grass looks perfect, sending his own gardener to Nick's house to tidy things up. He even sends a "greenhouse" of flowers to decorate Nick's home.

On a day when Gatsby is supposed to be reunited with the love of his life, you would expect a bright, sunny day, full of warmth. Yet as Gatsby arrives, it is "pouring rain." This is a reminder that Gatsby is not in complete control of this meeting with Daisy. It casts a sense of gloom over the meeting, particularly as he becomes more convinced that Daisy won't show up. Finally the rain begins to pass just before Daisy's much-anticipated arrival. Her presence is juxtaposed to the rainy and gloomy mood thus far:

Under the dripping bare lilac trees a large open car was coming up the drive. It stopped. Daisy's face, tipped sideways beneath a three-cornered lavender hat, looked out at me with a bright ecstatic smile.

Though the rain has reflected Gatsby's pervasive sense of melancholy in awaiting this arrival, Daisy's "bright ecstatic smile" lifts this sense of gloom even as the trees continue to drip the remnants of rain behind her. This indicates the power Daisy has over Gatsby and the influence she has on his emotional state.

Daisy and Gatsby begin getting reacquainted inside the house, and Nick quietly excuses himself to give them some privacy. Once outside, he notices that the weather has shifted:

After half an hour the sun shone again.

The day has become clear and bright, reflecting the way Gatsby's spirits have improved upon Daisy's arrival. He believes that this moment is the culmination of years of determination and that his tormented longing for the girl of his dreams is over.

Anytime an author presents weather, it is typically not just rain, snow, wind, or sunshine; it is a message about the action of the storyline.

In this instance in chapter 5, rain can signify renewal of a relationship. It can wash away the past. It can cleanse what was wrong with the past so that the future can go on in purity. This rain happened in the middle of the day, and only for the time during which the meeting between Gatsby and Daisy was held. Had the rain been coupled with thunder and lightening or wind, it might signify a different change. In that case, it could foreshadow trouble. Here it's singular purpose is to demonstrate the birth of a relationship refreshed and cleansed. It is a little like a shower.

Describe the effect of rain on the plot in Chapter 5 of The Great Gatsby.

Chapter five finds the rain continually starting, stopping, dripping, and even "misting."  The sheer amount of rain mentioned in this chapter absolutely surprised me!  It is the chapter where Gatsby plans and succeeds in both inviting Daisy to tea at Nick's house and then over to Gatsby's to rekindle their love without Nick around. So, let's explore the rain here with a stress on its ability to affect plot.

Ironically, the first thing the rain does is to not affect the plot at all.  Despite the downpour, Gatsby sends his lawn mower over to Nick's house anyway.  Everyone knows that one doesn't cut grass in the rain, so this shows that Gatsby wasn't going to let a little thing like weather get in the way of his first meeting with Daisy.  Further, there's no real plot development associated with Daisy entering Nick's house driving "under the dripping bare lilac-trees" (89).  Although this adds to Daisy's mystique, perhaps, it doesn't really do much in the way of plot.  Daisy comes in, she's a bit wet, Gatsby wants to make an entrance so he stands outside in the puddles and rings the doorbell, Nick tries to leave them alone and runs out into the rain for a while, etc.  No real affect on plot development yet.

Then some interesting things begin to happen.  The rain stops.  Immediately, Nick notices this:

While the rain continued it had seemed like the murmur of their voices, rising and swelling a little now and then with gusts of emotion.  But in the new silence I felt that silence had fallen with the house, too. (89)

Interesting!  The background noise of the rain seems to have a part in making the relationship happen for Gatsby.  When the rain stops, Gatsby has won Daisy back and now "he literally glowed; without a word or a gesture of exultation a new well-being radiated from him and filled the room" just like the way the world looks beautiful and new after a rain (90).  Such is our first inkling of how the rain affects plot:  the end of the rain makes it possible for the three of them to walk across the lawn and move to Gatsby's house (instead of Nick's).  When Gatsby realizes that the rain has stopped "there were twinkle-bells of sunshine in the room" and he says to Nick, "I want you and Daisy to come over to my house, ... I'd like to show her around" (90).

Finally, I would be amiss if I didn't mention the significance of the mist near the end of the chapter because it obscures the green light at the end of Daisy's dock:

"If it wasn't for the mist we could see your home across the bay," said Gatsby.  "You always have a green light that burns at the end of your dock." (94)

Just like the mist obscuring it, "the colossal significance of that light had now vanished forever. ... His count of enchanted objects had diminished by one" (94).  However, the irony is that Gatsby now has the real Daisy right there, linked arm in arm with him.  Is he satisfied with the reality, ... or is his mind still in the dream?  Ah, but that's another story.

My conclusion, then, is that rain truly does bring possibility for Gatsby. Gastby won't let the rain ruin his plans, and as a result the rain brings relaxation and love along with excitement.  The end of the rain symbolizes the beginning of Gatsby's and Daisy's love affair, ... and they frolic across the lawn together leaving Nick in the dust.  One wonders what happens between the end of Chapter 5 and the beginning of Chapter 6.  Hmmm, I could easily guess.