Mason bee release

So this will be my first release season with the bees; last year I purchased my cocoons online (maybe April?) and set them out with the houses I built. At the end of the season I found that many new cocoons had been produced and I washed them, discarded the badies, and stored in my fridge in a stapled toilet paper tube.
Now it is coming close to the following spring, I have cleaned my boxes but am unsure when to put them out. I live on the Oregon coast and a few bushes and trees have begun blooming but I don't want my bees to be stranded without food if I out them out too early. Any advice would be welcome
Thanks  

 I release mine a few weeks after my last frost date.  Temperatures need to stay above 55 or so and many trees and plants are flowering/ buds opened.
   It is better to wait if you think some more cold weather is on the horizon for your area.

Ralph Sluder wrote:  I release mine a few weeks after my last frost date.  Temperatures need to stay above 55 or so and many trees and plants are flowering/ buds opened.
   It is better to wait if you think some more cold weather is on the horizon for your area.

Perfect, thank you Ralph