Peas are one of the first crops we plant, generally as soon as the ground can be worked. The seed of most varieties will continue to grow even if snow falls after they are planted. A blanket of snow doesn't hurt emerging pea plants either, so long as the temperatures are not frigid, in the teens or lower.
Cowpeas, Field Peas, crowder peas, black eyed peas,and cream peas are not actually peas they are more closely related to beans and will live long and prosper in warm hot summers.
Among True Peas, there are extra-early, early, mid-season, and late varieties.
Pea plants are easily grown within the narrow time frame which is their growing season. They also do not stay fresh very long after harvest, so should be used or preserved quickly once harvested.
Optimally seeds should be sown outdoors 4 to 6 weeks before the last spring frost, soil temperatures should be in the ballpark of 45 degrees F. Air Temperature most definitely should be below 70 degrees F which is generally not an issue for spring plantings.
If you plan to grow early peas, placing a cloche or tarp over the soil for several weeks before sowing will allow the ground to warm up. Raised beds will also help with early plantings.
Getting them in the ground while the soil is still relatively cool is good, not cold but workably cool is cool. Do not allow them sit for extended periods in soggy soil.
Turn over the planting beds in the fall, add manure to the soil, and mulch well. Adding manure in the Spring is not advisable, just mulch. Turning over the beds is still a good idea though.
A modest sprinkling of wood ash to the soil before planting is a good idea. Wood Ash is a good source of lime and potassium as well as many other trace elements that benefit plants. It is best used in moderation, scattered lightly and well mixed into your compost. Wood ash produces salts and lye and if not used sparingly can damage or kill your plants.