Dairies in this area are now on a fall incentive program that DFA came up with to try to get more milk in the fall for "school contracts". They are penalizing any milk production over a base amount in the spring. So farmers are now trying to shift their breeding to more calvings in the fall. But many are still trying to keep it evened out thoughout the year. Calves tend to be more in demand when the weather is nice, in the spring/warmer months for kids to not have to go out in 0* weather to feed a bottle before school.
Do yourself a favor and go to a dairy or two and see if they will sell directly off the farm to you. Saves them some commision, and time to haul calves to market. But the biggest thing is the calves will more likely have had a feeding or two of colostrum, and will not be exposed to all the germs that travel around the stockyard/sale barn. If they have calves they might be willing to sell you some directly. I have not bought a calf from the stockyard in years and have greatly increased my survival rate.