Desert, California, and Rocky Mountain Bighorn Sheep are all extremely difficult tags to draw and for most, are considered a once in a lifetime hunt. If you are lucky enough to draw the tag, you definitely do not want a lack of gear to be the downfall of this once in a lifetime opportunity.
For the California and Rocky Mountain Sheep, the hunts take place in the early fall and run to the end of October. The weather can be extremely hot in the earlier season with the potential of heavy rainstorms. Toward the end of the season, you can expect the mornings to be brisk with the temperature rising throughout the day but still continue to be warm.
For the Desert Bighorn Sheep, if you are hunting the southern part of the state, warm temperatures are to be expected. While taking place in November (mostly) it does not get quite as hot during the summer, it will still be warm. You will want to bring some lightweight gear but be prepared for the potential of rain/cold weather. The units in the northern part of the state will see very cold temperatures the later you get into the hunt. Sub freezing temperatures can occur during December up North and you should watch the weather to better anticipate any storms or heat waves to make sure you are as prepared as possible.