I’m making this a regular blog post because WordPress won’t let me put links in the comments section. (I’m working on this!)
I went to the Cal Fire homepage for Northern California and looked at the latest incident report and the latest statewide map. There are no major fires around Desolation Wilderness, including the Sylvia Lake and Lyons Lake area. However, thick smoke can come in from many miles away, and there is a very large fire burning now near Yosemite National Park.
I suggest you contact the Pacific Ranger District of the Eldorado National Forest at 530-647-5415 and ask about conditions just before you leave home. You can also call the Lake Tahoe Basin Management Unit, which has jurisdiction over much of Desolation Wilderness, at 530-543-2694.
It looks like you might live near Arcata on the coast. Consider hiking in the Cascades of southern Oregon. You’re more likely to have a smoke-free experience there, again depending upon wind directions.
How is the smoke situation in your area? I lived near Crescent City for a few years and well remember ash raining out of the sky from the Biscuit Fire in the summer of 2002.