Western Springs can get fairly cold in January, but the rest of the year is more moderate in temperature. Keep a jacket on hand for the winter months and an umbrella for the occasional rainy day.
The area would be expected to be very artificial as well, given it's location so close to a big city. However, the area is surprisingly green due to the loyalty of the neighborhood to maintaining beautiful sidewalks and yards. The loyalty of the county to maintaining beautiful parks also helps bring this area from artificial to a little bit more natural.
Finally, some of these parks are completely unique. One example of this is Katherine Legge Memorial Park which features a beautiful English structure from 1927, a playground, sports areas, and a full disk golf course. Another great example is Spring Rock Park. This 40-acre park features a playground, athletic fields, lit tennis courts, picnic areas with barbecue pits, and several flower gardens.