Question
I would like to thank you for a GREAT response. I have printed your answer and will keep it handy for future reference. My question now deals soley with the time element for watering a newly soded lawn. How many hours a day/how many days a week/for how many months should the new sod be watered until it is established? -------------------------
Followup To
Question -
I live in the Chicago area and recently had my back yard covered in sod due to recent construction. I would like to know the best way to care for the sod to insure a healthy growth. We are now experiencing our first real touch of fall with tempts below 35. At what temp should I water and for how long on a daily basis (both in hours and weeks) should I continue to water? Thank You.
Answer -
A lawn needs water in the fall and winter as well as in the spring and summer, just not as much.
If you have had no rainfal in a couple of weeks, then water.
Snow in the winter provides the water.
Right now, if there is no snow on the ground, put sugar on the lawn, at the rate of 1 pound per 250 sq.ft.
This will keep the beneficial microbes in your lawn alive.
Fertilizers kill beneficial microbes that enrich the soil. Weeds love poor soil, and will not thrive in rich soil. Keep these microbes alive and well and you will not have to use weed killers.
If you just feel you MUST fertilize, put it down, the put down the sugar and water them in together.
I have not put one grain of fertilizer on my lawn in 8 years, and my lawn is thick, dark green, and weed free.
I use NO weed killers or insecticides.
I don't allow anyone to put anything on my lawn or garden that will harm my lawn critters. I have toads, grass snakes and lizards. They keep the bad bugs away bettetr than all the chemical insecticides I ever used did.
I used to spray my roses once a month, and still when the buds opened there was aphid damage. Since I have let my lizards feast on the aphids, I have not seen aphid damage on a single bloom.
Weed killers, fertilizers, and insecticides, and fungicides are poisonous to natural predators that will live in your lawn and take care of it for you.
For fungicide, I use baking soda disolved in water. works better than chemical fungicides, is cheaper, and since I use no chemicals, my Asthma is 95% better.
In very cold climates, a light watering just before a freeze actually insulates the grass somewhat and helps protect it from freeze damage.

I always water to a depth of at least 6 inches, to encourage a deep root system.
Shallow watering makes the roots have to come to the surface to get water. This leaves them vulnerable to heat, cold and drought damage. A deep root system helps protect against these damages, and also prevents thatch.
I had to dethatch this lawn when we bought this house 39 years ago, and have practiced a deep watering program and have not had to dethatch since.
Organics is more about what you DON'T do that what you DO.
This is my organic lawn care program.
Spring:
Strew cedar bark mulch all over lawn, and put a line of it around the foundation of the house to keep away termites, when it is time for them to swarm.
When it is time for fire ants to swarm. Chop orange peels and scatter them all over lawn. I never see a fire ant in my lawn.
Put down sugar and water in thoroughly.
Set mower blades to 2-1/2 inch height.
Mow, edge and water.
Spray new growth on shrubs and roses with baking soda disolved in water to prevent molds, and fungus.
Continue to mow, edge and water. Deep water always to a depth of at least 6 inches, and re-water when the top two inches of soil are dry.
When temp reaches 85 degrees, set mower blades to 3 inch height.
Mowing at 2 to 2-1/2 inches in early spring helps grass thicken up, if grass is a type spread by runners, like burmuda, St. Augustine etc.
Setting the mower blades higher in the hotter temps helps to shade the soil a bit and keep it cooler to minimize heat damage.
NEVER SCALP A LAWN!!!!!!
Fall:
Put down sugar and water in well.
Leave grass a tad taller to help insulate lawn from winter freezes.
Water when there is not enough rain to give the amount of water necessary for the grass to live.
Aside from pruning shrubs and planting plants etc, that is all we do.
We leave the grass clippings to compost and make food for the grass.
Mow grass when there will be no more than 1/3rd the grass blad height cup off.
Letting grass grow too tall and then mowing makes your gradd look reedy.
For instance, mow when grass is no more than4-1/2 to 5 inches high, and cup off no more than 2 inches.
On n organic program, the grass grows at a slower rate, so once a week mowing does it. When you fertilize, it gets a growth spurt and you have to mow more often to keep it the right height.
For flowering shrubs, or shrubs or trees that bear fruit, I use an organic food, as fruit or flower production takes a little more food than than just maintaining healthy plants.

If you use a chemical program, you must feed and weed in spring, spray with insecticides on shrubs and flowers, about once a month. spray with fungicides, once a month.
Kep weed killers on hand to kill new eeeds.
Dig out bothersome weeds such as crabgrass, johnson grass, dandelions etc.
Fertilize again if lawn starts to look faded.
Apply insecticides to particular problems such as web worms, grubs, army worms etc.
Mow and edge.
Feed again in the fall with a winterizer to  keep winter damage down, put down insecticides for fall pests. give a fall weed killer application.
It goes on and on.
My lawn critters take care of all thiose pests for me.
Cedar bark mulch keeps away termites, fleas, ticks, and a host of other insects. It is fine enough that it sifts into the grass and does not look messy, and it does not harm mower blades. It composts and adds nutrients to the soil.
Chopped lemon peels keep cats from using your flower beds for a little box.
I jjst chop the peel of each lemon I use, and scatter it in a pattern all during the year, so it keeps the flower beds and potted plants free of cats. I love cats, but don't like the surprises they leave in my flowers.
In the spring when fire ants swarm, is the only time I bombard the lawn with orange peels.
I buy a big bag of oranges and my grandkids and my neighborhpps kids eat the oranges, I chop the peels and they scatter them. It is yearly ritual. LOL
I grow my own herbs for cooking, and rosemary keeps cockroaches out of my house. I put a small piece, about 2 inches lng, on each pantry shelf and under the appliances, anywhere roaches can come in ir hide. I never see a roach in my house.  Every 2 or 3 months is often enough to do this.
A big container of lavender at each door keeps house flies out of my house, and makes beautiful entryway planters.
I buy a small bottle of cedar oil at a healthfood store, and paint a strip on the clothes rods in my closets, and around the baseboards, to keep moths out of the closets.
I NEVER use poisons, and since I went organic, I have NO pests to deal with, inside or out.
cockroaches are great to have in the lawn, because they are good aretors, but i can't abide one in my house!
Write anytime you feel I can help.
Charlotte  

Answer
It depends on what kind of grass you sodded in.
St. Augustine you want to keep pretty damp until it stes roots, Burmuda as well.
for your climate and types of grass, you would do better to ask a local nurseryman.
I am thinking you would already have snow and ice in chicago.
I have never lived in that area.

If the grass is rooted in, then as often as the soil is dry enough for the grass to start looking a little depressed.
You don't say how long it has been sodded in.
Here are some sites i found that may give you better information than I can.

http://chicago.about.com/cs/lawncare/

Also contact your Agricultural Extension agent for your area.
They will give you all the information you need.
Grass is a little more forgiving than shrubs etc. they will begin to look a bit depressed, and a good watering will perk them tight up.
at this time of year, whe grasses go dowmant naturally, it is harder to tell if they are distressed or just dormant.
Your agricultural Extension agency has all the information about your climate, rainfall, and whether or not you are getting enough moisture to keep your lawn through it's dormant period.
I wish I could help you more, but i am just not that familiar with your climate there.
Charlotte