Summarize:

Antarctica's tour season covers about five months, mostly over the Southern Hemisphere summer (November to March). All other times of the year are extremely cold, dark, and the pack ice freezes out a long way. Be aware that while there will be less people around later in the season, much of the wildlife will already have left and headed out to sea. During these months, some of the things you can expect include:  During November, the pack ice starts to break up and it's mating season for the penguins and other birds. During December and January, the penguin chicks hatch and are fed and nurtured in the breeding grounds. During February and March, the penguin chicks fledge, the adult penguins molt, and the whales are easy to spot. This is one travel destination where budget travel is not much of an option unless you're hired to work hard. At a minimum, you will probably be facing at least US$5,000 and that is for the bare necessities and not necessarily the best seating or opportunities.  It is possible to get cheap last minute deals with cruise ships in places like Ushuaia in Argentina. You need to be in town, flexible, and able to set off straight away. This is a risky option, but if it works you could save quite a lot of money.  If you don't want to visit as a tourist, think of other options, such as joining a government expedition to Antarctica. For this, you'll likely need suitable technical, scientific, medical, or other relevant skills like cooking for a large group. You will also need to be considered to have a suitable background for government employment.  Another possibility is to travel as an invited part of a crew. Some people get asked to come along as journalists, photographers, artists, etc., and their trip is covered by whoever invited or sent them along. Again, this will depend on your skills. The Antarctic environment is dangerous for human beings. The weather can deteriorate rapidly and it is always cold, even in the summertime (highs in the summer along the coast generally range from 41–56 °F (5–13 °C)). There are dangers such as crevasses on ice fields and glaciers and fire hazards are high in the very dry environment, so handling anything flammable must be done with care.  Read up on the gear and clothing you need. You will definitely need excellent waterproof clothing! Your cruise ship will most likely have things to hire if you don’t have them, but they might not be a great fit.  There are no vaccination requirements for Antarctica but you should be fit and in good health because medical treatment will be basic and spread thin among all your passengers. Any medical conditions that you do have should be detailed by your doctor in letter form, especially if you need to bring along medication. The Antarctic environment is fragile and apart from expeditions, bases, and some tourists, there has been little human change. Wildlife remains unafraid of humans because of the lack of long-term negative interaction. It is important to respect the pristine nature of Antarctica and to ensure that tourism doesn't have a negative impact. There are Visitor Guidelines adopted under the Antarctic Treaty that regulate visitors' actions at Antarctica and it is worth reading them as part of your preparation for the visit. Some of the basics to keep in mind include:  Don't go too near wildlife and don't do anything to disturb wildlife. Don't litter. Don't deface anything – all human-built structures have historical value and many huts, etc., have heritage listings. Do not engrave anything into rocks or other land features.  Take photos and nothing else. Leave all eggs, shells, plants, rocks, fossils, soil, etc., where they are. This is one of those trips that people who take it can never forget or stop talking about. If you love pristine beauty, amazing sights, incredible wildlife opportunities, and you don't mind a bit of cold, this might be the perfect trip that will create a lifetime memory.
Choose the right time to visit. Expect a large hole in your budget. Understand the health and safety issues. Respect the fragility of the Antarctic environment. Enjoy your trip of a lifetime.