Military Standards:

MIL-STD-810 Environmental Engineering Considerations and Laboratory Tests:

Method 501 High Temperature
Method 502 Low Temperature
Method 507 Humidity

MIL-STD-202 Test Methods for Electronic and Electrical Component Parts:

Method 103 Humidity (Steady State)
Method 104 Immersion (Method A)
Method 108 Life (at Elevated Ambient Temperature)
Method 301 Dielectric Withstanding Voltage
Method 302 Insulation Resistance
Method 303 DC Resistance