cold, humid air makes starting difficult, gasoline doesnt vaporize, instead turns into tiny droplets, it won't ignite properly in those conditions.
another thing that may be bad are the temperature sensors, try disconnecting them, this forces the ECU into believe that is deep cool outside and adjust the fuel accordingly. if it starts with the temp sensors unplugged then one or both are defective, just try to no leave them unplugged when it reach operating temp or the mix will be too rich
it helps by shutting down the injectors so air push the excess fuel out