I like AHS's suggestion since many sites are closing parks to the visitor (like our local Stanley Park). So here are the tips:
Lean on the Centers for Disease Control (CDC) and World Health Organization (WHO) for the most reliable, science-based, and up-to-date information about COVID-19. They update their webpages frequently.
Check The Trek for park closures that may affect trails.
For cancelations of events and closures that are related to the National Trail System, see the Partnership for the National Trail System website.
Try to get outside for at least 20 minutes every day, even if it’s just for a couple of laps around the block or playing with your kids.
If you do decide to travel to a trail for a hike or go to your local park, please practice social distancing, vigilant handwashing, and avoiding touching your face.
I like the last two most!
For more info, visit AHS.
Oh yeah, in Massachusetts, state parks are open although visitor centers are not.