Climate definitely plays a role, but not in the way that you might think. To help narrow this down, I'm going to focus this answer on Utah. First though, we need to take a step back to review what was happening in Utah at this time.

Brigham Young led the Mormon Pioneers to settle in Utah in 1847, fleeing from religious persecution in Nauvoo, Illinois. Young partially chose to settle in Utah because it was in Mexico and not part of the United States. Young was looking to cut ties with the United States government and establish independence for Mormons so they could practice their religion freely.

When thinking of early Mormons in Utah, polygamy is probably the first thing that comes to mind and not slavery. This was also true back in the early 1850s. If the federal government had known how widespread slavery was in Utah, they may have reconsidered the compromise. In 1852, Orson Pratt, an apostle of the Mormon Church, gave a speech publicly defending polygamy as a tenant of the church. The outrage over polygamy followed shortly thereafter and thus slavery in Utah went relatively ignored.

Mormon lobbyist John M Bernhisel worked to convince Congress that the climate of Utah was inhospitable towards slavery since it was too arid and remote. Without the railroad to bring slaves in, it seemed unlikely to outsiders that slavery would gain traction in Utah (even though it already had).

Since Utah didn’t share a border with current slave or free states, people couldn’t (or wouldn’t) travel to Utah in the same way that they could travel to Kansas. In this way, Mormon lobbyists could control the narrative around what was happening in the state. The only other accounts regarding Utah at that time were settlers passing through on their way to California. The majority of those accounts lined up with the testimony from the lobbyists in Congress that the climate was exceptionally arid. In this sense, the perception that the climate was not right for slavery was enough to satisfy the rest of the nation. No one outside of the Mormons felt particularly compelled to visit Utah to find out the truth.

While the perception was that polygamy was the bigger issue and that slavery wouldn’t gain traction, it wasn’t the reality. The Mormon settlers brought three slaves with them when they arrived in 1847. They also quickly got caught up in the Mexican’ colonists slave trade of Native Americans. The reasons given for participating in the Native American slave trade vary, but common threads include a desire to save the Native children, indoctrinate them into Christianity, and also to use them as cheap sources of labor.

As more Mormon settlers arrived in Utah, they also brought their African slaves with them. In 1852, “An Act in Relation to Service” was passed by the Utah Territorial legislature which legalized slavery and also contextualized it within the Mormon belief system. Young noted that legalizing slavery could win converts to the Mormon religion from Southerners looking to leave with their slaves. Slavery wasn’t banned in Utah until the end of the Civil War. The Act was passed without much fanfare and without the attention of the federal government.

In short, slavery existed in Utah without much controversy because Utah was too remote and no one except the Mormons cared to visit long enough to find out the truth. The perception of an arid climate was enough to satisfy Northerners that slavery wouldn’t gain traction, even though that wasn’t the reality. Polygamy also overshadowed the issue of slavery in relation to national debate over Utah.

I do also want to note that while Utah didn’t explode in a way similar to “Bleeding Kansas” in relation to slavery, it isn’t completely without conflict. In 1856, it was a key tenet of the Republican Party platform "to prohibit in the territories those twin relics of barbarism: polygamy and slavery.” After increased scrutiny regarding polygamy and concern of Young’s control of the territory in what could be dubbed a "theodemocracy,” President James Buchanan sent troops into Utah starting the “Utah War” in an attempt to regain control of the area (however, that probably warrants a different post).