It depends on your skin type. In April (if it's over 75 degrees and sunny) I can go out and wash my car or cut the grass in a tank top and, when I come in, I can see tan lines.
The key is: not too much at one time. It's very bad to lay out for hours to get a tan, even with lotion on. Gradually tan, then make sure you use a good aloe lotion each day. My tan usually hangs around from April until late October (but then, I have that self basting Italian skin that secretes olive oil)
and I also ride my Harley 3-4 times a week in Spring & Summer...