Fellow bicyclist Ricky had shared his tips for what clothes to wear when bicycling in various temperatures. I think it’s a good guide on what to wear. For what it’s worth, here’s my guide for outerwear for both commuting and recreational riding. I tend to run colder than he does, so I tend to start layering earlier.
70+/21+ Short-sleeved jersey/shirt, shorts, crew socks, half-fingered gloves, shoes, helmet.
65-70/18-21 Add armwarmers, swap shorts for capri tights/skinny pants.
50-65/10-18 Add light jacket, swap short-sleeved shirt for long-sleeved shirt.
40-50/4-10 Swap light jacket for medium-weight jacket, swap capri tights for full-length tights, add silk top baselayer, swap half-fingered gloves for full-length gloves, change to wool socks, add wool cap, neckwarmer, toe covers.
32-40/0-4 Swap medium-weight jacket for 3-in-1 jacket, add biking pants to tights/add long johns to pants, change to fleece neckwarmer, swap toe covers for booties.
20-32/-6-0 Swap full-length gloves for lobster gloves, swap shoes for hiking boots.
Below 20/-6 Swap silk top baselayer for medium-weight synthetic baselayer, add one more layer top and bottom (if in teens or below), consider chemical hand/toewarmers, face protector cream.