Can anybody help me with an average daytime temperature for beginning to mid March for Sedona. I'm trying to find out if it will be warm enough to rent a convertible car or not.
Thanks a bunch!

According to the numbers at http://weather.yahoo.com, for March 1-15, the daily lows in Sedona average 35-37 degrees and the daily highs average 62-65 degrees.

And for the record, that's quite cool when you're in a moving car and the top is down. My top doesn't go down unless it's over 70 (with sun).

Plus it's pretty dry in Sedona, so it feels cooler than the temp might suggest.
My advice?
Skip the convertible unless you're planning on spending time in Phoenix or Tucson as well.
Sedona is NOT a warm and balmy place in early March (on average).
Neither is Phoenix.
We visit every March and while it's very pleasant (which for me means over 75) some years, most years it's in the 65-70 range. It doesn't make you think about swimming.

Don't forget that it can and does snow in Sedona in March.

BTW, I meant that Phoenix averages 65-70 in March, not Sedona.
Sedona's average daily high in early March is 61, and daily low is 34 (!!).

Thanks for all the input. I will scrap the idea of a convertible. My husband would want it down if it's in the 60's but I would freeze and I'm making the arrangements!
Thanks again!