Very definitely. Liquid ring vacuum pump manufacturers publish capacity curves (CFM and vacuum level) assuming that the seal water is at a fixed temperature (typically 60°F).
When the temperature of the seal water is lower than 60 F, its vapor pressure decreases and the pump capacity will increase.
When the temperature of the seal water is higher than 60°F, its vapor pressure increases and the pump capacity will decrease.
The capacity curves have correction factors to account for these temperature variations.
If the seal water temperature is too high, the liquid ring pump will be unable to achieve a low vacuum level.