Here is some general info for USDA zone 2a to help you get started.
|Average Date of Last Frost (spring)||May 15|
|Average Date of First Frost (fall)||August 15|
|Lowest Expected Low||-50°F|
|Highest Expected Low||-45°F|
This means that on a really cold year, the coldest it will get is -50°F. On most years you should be prepared to experience lows near -45°F.
Below is a list of planting guides for Zone 2a.