Surface temperatures are hot enough to melt lead. The surface pressure on Venus is the crushing equivalent of being nearly a mile deep in Earth's ocean. The landscape, covered in volcanic rock, is desolate and waterless, but rich in sulfur. Venus's atmosphere is more than 96 percent carbon dioxide, with 3 percent nitrogen and traces of other gases.
Enshrouding Venus are three distinct cloud layers. Water vapor there ranges from a few parts per million at the top of the cloud deck to a few tens of parts per million at the base. Cloud droplets, however, are formed of extremely concentrated sulfuric acid. Now toss in for good measure a high flux of solar ultraviolet radiation that floods the cloud deck. [emphases added]
But [planetary scientist at the Southwest Research Institute David] Grinspoon added that if there is life in the clouds of Venus, “then it exists in conditions which do not overlap conditions in which even extremophile terrestrial organisms can survive.” This life, he pointed out, would be so alien to Earth life that it and Earth life could not threaten each other.
That's good to know. Of course, a life form adapted to living in clouds of sulfuric acid wouldn't be very cuddly, either. So, we'd probably leave each other alone for the most part.