What is the weather like on Venus in "All Summer in a Day"?

On Ray Bradbury's Venus, it rains all the time, night and day. In fact, the sun only comes out for about an hour once every seven years. There is a constant noise in the background of rain falling.

None of the nine-year-old children in the story except Margot can remember ever seeing the sun. As a result, the other children envy Margot for her knowledge. Margot can remember the sun because she came from Earth to Venus later than they did.

The children are beside themselves with joy and excitement as they play outside for the brief time the sun comes out. As the story states, they were:

like animals escaped from their caves, they ran and ran in shouting circles. They ran for an hour and did not stop running.

As a result of this lack of sunlight, the terrain the children play on is very grayish and white. It is described as:

the color of rubber and ash, this jungle, from the many years without sun. It was the color of stones and white cheeses and ink, and it was the color of the moon.

Unfortunately, the children who have locked Margot in a closet as a prank forget about her in their excitement over the sunshine.

What climatic conditions are imagined on Venus in "All Summer in a Day," and what Earth locations resemble these conditions?

The climate on Venus is relentlessly rainy, with the sun only emerging once every seven years. As a result, the planet has a ghostly or spectral quality, the vegetation gray and whitish. We learn that the intensity of the rain varies: sometimes it is "the sweet crystal fall of showers," an almost lovely image, and others time, harsh, "the concussion of storms so heavy they were tidal waves." The rain dominates all aspects of life. It is so overwhelming that "a thousand forests had been crushed under the rain," and the humans from earth have to live in an underground city. 

We also learn that the planet is noisy from the constant rain: when the rain stops, the children can hardly believe the silence. When it stops, they can also see how black and white everything is: "the color of stones and white cheeses and ink." 

The planet seems most like a rainforest on Earth, but perhaps one growing in underground caverns watered continuously through deep crevices in the rocks.