Exactly how long the virus survives depends on many factors - temperature, humidity levels, sunlight, etc. It should be noted that freezing temperatures are protective for this virus; cold temperatures won't kill parvo.
Disinfecting the Environment of Parvo
NOTE: This section of the article is about environmental treatment for parvo. If you suspect that your dog or puppy has or has been exposed to parvo, please see your veterinarian as soon as possible. Time is of the essence for improving chances of survival.
Parvo is considered to be ubiquitous - it is potentially everywhere in the environment. The key is to minimize the amount of available virus and protect your dog through vaccination; activating the immune system to fight off the virus before it causes disease. Puppies younger than 16-18 weeks of age haven't had all of their vaccinations yet, so they are more susceptible to parvovirus. Therefore special caution is advised for puppies; be mindful of the areas visited, vaccination status and age of dogs they come in contact with, and be extra vigilant about sanitation of hands, shoes, clothes, bowls, etc. for puppies.
The mainstay for parvo disinfection for the environment is to use a diluted bleach solution on cleanable surfaces (never on an animal!). The type of bleach varies the "strength," but a general rule of thumb is: 1 part bleach : 30 parts water. Learn more about the types of bleach, handling instructions and dilution factors: The Bleach Niche.
Washable surfaces may be cleaned with a dilute bleach solution (test small area of the item first). Washing with large amounts of water may help 'dilute' the virus from areas such as lawns. For furniture, carpets and other difficult-to-disinfect areas in the home, waiting 4-6 weeks should be sufficient time for the virus to die off before introducing another puppy.
Related: Is Parvo spsread via vomit?