This spring I've found that shorts are OK to head out in the mid to upper 40s, but if starting out in the low 40s and it doesn't promise to get sunny or warm up much, lightweight tights or some warmers may be advisable.

For the upper body, it depends on whether it will warm up much. If the temperature swing is expected to be more than 10 degrees, a lightweight, compressible windbreaker or rain cape is advisable, under which a base layer and regular jersey may be sufficient. If its going to get sunny and warm, removable arm warmers may be preferable. If it's going to stay cool, a base layer and long sleeve light thermal jersey are usually fine.
As others have suggested, what goes for 40s to 50s in spring seems to apply equally to 50s to 60s in the fall, generally speaking. However, I find the need for heavier gloves and warm socks and boots isn't so seasonal: mid 50s and below calls for full finger gloves, 40 and below thermal gloves, but warm boots not until near freezing.