If you're the kind of person who needs a black and white answer, the answer is no.
If you prefer to wade through complexity, the short answer is: as long as you're very confident you can keep 6+ feet from others, consider it.
For others, it will risky because their normal walk is crowded right now.
Keep at least one hockey stick away from others, don't touch anything (even people's pets), and enjoy the sunshine.
Mental health is important! Getting some exercise outdoors has legit health benefits.
Social norming is important too. The more people see others outside, the less inclined they may be to carefully keep a safe distance from others.
Again, no perfect answers.