Because there does seem to be an ambient temperature correlation, I'd first check the function of the Intake Air Temperature (IAT) sensor and the Engine Coolant Temperature (ECT) sensor. It's possible the IAT sensor is integrated in with the MAF, but I think that became more common after 1995.
I recall the 2.3L Ford engines had quite a problem with Ignition Control Modules being temperature sensitive and causing stalling, but they generally acted up more when hot which should have still happened in the Spring and Summer. Similarly, the Crankshaft Position Sensors would commonly cause stalling, but they were less intermittent.
-Rod