I would think that the water temperatures at Lenice, et. al., should, with this years unusually cold temperarures, hold up through July at least. I was there a little over a week ago and, while I didn't take any temperatures, the water seemed quite cool. The fish were active and showed none of the sluggishness that one would associate with warm water.
I think they are nearing upper 60's to 70. I got a report from one south of there and they are usually the same. I'm switching to rivers and mountain lakes now. I told the lowland lakes I will see them next fall.
I would think the water should be cool enough to fish until at least July. The temps in Eastern WA have rarely gotten above 70 degrees (rarely gets above 65 degrees) and Lake water here in the Kittitas Valley are still quite cold.
The temps here in the Kittitas Valley have rarely reached 70 this spring, actually rarely reached 65 this spring. Our lakes in the Kittitas Valley are still fishable. My guess is that the desert lakes should be fishable until July. Water temp in a lake is reflected by the air temp. We are having a very cold and wet Spring in the desert.