According to AWS D1.1 Table 3.2 note 1, "When the base metal temperature is below 32deg F, the base metal shall be preheated to a minimum of 70deg F and the minimum interpass temperature shall be maintained during welding.
Section 5.12.2 addreses the ambient temp and basically says welding shall not be done when the ambient temp is lower than 0deg F, or surfaces are wet,or exposed to rain, snow, or high wind velocities, or when welding personnel are exposed to inclement conditions. There also is a note about the ambient temp not necessarily being the enviroment but the temp in the immediate vicinity of the weld.
AWS D1.1 section 5.3.2.1 and 5.3.2.2 reference AWS A5.1 and A5.5 and Table 5.1 in D1.1 for electrode exposure time and conditions.
Hopefully this will help some or get you in the right direction.

Bill