Wondering how to pick a base layer

[Crankin]

I find the Ice Breaker to be itchy, but the Smart Wool micro weigh base layers are perfect. But I think even those would be too warm for when it gets to 60-70, if you have something over it. I lived in Tempe for 16 years and I know exactly what you are talking about. I would go with a Craft short sleeved or sleeveless base layer under a regular jersey, with arm warmers and a jacket, so you can remove the layers as it warms up. If you are going out only in the morning, then I would wear the micro weight wool as a base layer; I think they have short sleeved versions, so you might try that under your jersey.
I know that I always left my coat and gloves at work in the afternoon, because it was hard to remember a winter coat, when it was 70 degrees when you went home!

[azfiddle]

Thank you for all the suggestions, (especially Crankin, for your AZ experience) Sharon

[Owlie]

BF (from Mesa) says +1 on the Craft base layer, if you haven't already made your decision.

[azfiddle]

Still accepting suggestions. After all, despite a surprising 3 day cold snap last week, it's now back to record-breaking warm temps in the 80's and 90's this week. I'll look at Craft ....