Between Yom Kippur and Succoth (the Feast of Booths), Jewish families spend some time (often a lot of time) constructing a Sukkah, a booth in which to "dwell" for a seven-day period. There are a number of requirements for this booth. No more than one wall may be a permanent wall, such as that of the family's regular house. It is usually decorated with fruit. And the roof can not be tight like a normal house; one must be able to see the stars through the roof. Often it is made of branches with the leaves on them or, in warmer climates, palm fronds.
In some parts of the world, like Albuquerque, New Mexico, late summer and early fall are the rainy season. Why would someone want to build a dwelling place with a leaky roof during the wettest time of the year?
Perhaps an answer can be found in the reason for this holiday. Leviticus 23:42-43 says, "Ye shall dwell in booths seven days; all that are Israelites born shall dwell in booths: That your generations may know that I made the children of Israel to dwell in booths, when I brought them out of the land of Egypt: I am the LORD your God."
How did God make the Israelites dwell in booths/tents? What else were they going to dwell in? They had just left their houses in Egypt, and were not yet to the houses waiting for them in Canaan. They had apparently brought tents with them. Other than that, they had little in the way of building materials. And even if they had brick or stone, or even wood, God kept leading them onward. They could not build permanent houses.
Therein is one answer. God kept leading them onward. There were several stages of the journey in which they spent a considerable time. They spent months at Sinai, for instance. Even after months in a place, though, God led them onward. He would not let them get comfortable and settle in one place, because He was taking them to a different place. He made them dwell in booths by moving the cloud/fire that led them. He made them dwell in booths by not allowing them to settle.
That doesn't answer the initial question, though. Why would God ask people to dwell in a house with holes in the roof during the rainy season? I think that relates to the next part of the statement in Leviticus 23:43: "when I brought them out of Egypt."
Israel was a nation of slaves. Albeit they were a strong nation of slaves, they were still slaves. They had no ambition to leave Egypt. Even when Moses came to them, their concern was that he was stirring up trouble and making their slavery harder (Ex 5:20-23). God provided signs and wonders. He led them out of Egypt "by a mighty hand and by an outstretched arm" (Deut 4:34). He led them. They did not lead themselves. They had to rely on God, when he brought them out of the land of Egypt.
By ordaining living in booths, God is reminding his people that it was not by their might that they came out of Egypt. From the first step into the wilderness they had to depend on God. They had to count on him for food and guidance. He provided protection and warmth at night, with the fiery pillar. He provided air conditioning during the day with the cloud. Don't you think He could hold off the rain for seven days, if His people would trust Him. That is what Succoth is really about, isn't it? After the Day of Atonement comes a week to say, "I believe you forgave me, God. And to prove it, I will trust you not to get me wet. And even if you do, I will trust you, anyway."
(Succoth begins on 2 October in 2001.)