Sounds like blossom-end rot and - based on recent temperatures - some blossom-drop as well...

"Blossoms drop when temperatures rise above 90. Nighttime temperatures below 60 or above 75 will also cause blossom drop. Normally, peppers will set additional flowers when temperatures moderate. Moisture stress also causes blossom drop.

Blossom-end rot first appears as a water-soaked area on the fruit. The tissue near the blossom end of the pods has a brown discoloration. Blossom-end rot in chiles, unlike tomatoes, is never actually at the blossom end of ther fruits. Spots elongate and become brown to black, dry and leathery. Pods affected with blossom-end rot usually ripen prematurely. Wilting, lack of soil moisture, and lack of calcium encourage the problem.

To control blossom-end rot, maintain uniform soil moisture through irrigation and avoid large amounts of nitrogen fertilizer.

suggest you csll your local agriculture office & talk to the person who does local gardening classes or gives advice to local farmers, also, go to your local farmer's co-op & talk to the salesperson. Local co-ops service local vegetable growers.