Chicago, one of the best vacation destinations in the State of Illinois, boasts a full host of attractions, recreational parks, modern architecture, diverse entertainment and much more. Besides, each year, millions of visitors are drawn to the city for a variety of events, festivals and conventions, such as Chicago Jazz Festival and Chicago SummerDance.

Outdoor parties and celebrations seem to be endless in the Chicago. However, weather in Chicago is fairly variable and changeable, with thunderstorm frequently a case particularly in summers, thus, outdoor activities are not always favorable, as no one would like to get soaked in the pouring rain. Then what to do if your Chicago trip happens to fall on rainy days? Here you are encouraged to bear some best things to do in mind in case of unexpected severe weather in Chicago.

Visiting museums top the list of best things to do in Chicago on rainy days! As a city with rich culture and history, Chicago showcases a wealth of museums, ranked among the best worldwide. From classic and modern art, photography, science and technology, to natural or industrial history, Swedish- American or Polish-American fine art - there must be a museum right for you! It is quite notable that many of these museums offer Free Days for Illinois residents or even out-of-state visitors on select days. So if the heavy rain or the abrupt thunderstorm messes up your itinerary, a visit to a museum sounds good. Some of the most-visited museums in Chicago include:

• Field Museum of Natural History (home to the most complete and best-preserved T-Rex)
• Museum of Science and Industry (the oldest and largest science museum in its kind in western hemisphere)
• The Chicago History Museum (the oldest cultural institution in Chicago)
• Chicago Childrens Museum (a top pick for family fun)

Chick here for a full list of museums offering Free Days in September, 2011 - making your visiting a greater value!

Though the theater scene in Chicago is not as prosperous as New York's, the quality and diversity are just as good! With an escape into the dark theater, who cares how severe the weather is outside? It is roughly estimated that there are hundreds of independent theaters in Chicago, more than a dozen of which are seated in the famous Loop. Rainy summer nights are acclaimed to be the ideal time for a short play, opera, comedy show or ballet. If you are lucky, you may take in those touring performances around the worlds or first-round shows of Broadway before they hit Broadway! Here are several best places to enjoy play or opera in Chicago:

• Steppenwolf Theatre (A Tony Award-winning theater with over 30 years of history)
• Goodman Theater (Chicago's oldest nonprofit theater that is still active)
• Lyric Opera (one of the leading opera companies in the US)
• Oriental Theatre/Ford Center for the Performing Arts (the major theater in Chicago for traveling Broadway shows)

If you are not that interested in museums, art galleries or theater performances, how about learning more about the city in the rain on tour buses with a local guide, or giving yourself a new image in upscale shopping malls? You can find our discussion on these topics in our Chicago Weather directory as well.