I got snowed on in the Sierra’s on 4th of July about 60 years ago.
I live at the Sierra foothills and remember dad in his winter coat barbecuing in a snow storm on the 4th. In fact, I think I've seen snow at least once in every month of the year in the Sierras. Conversely, I remember an entire February when the temps were in the 90's. We were in shorts and t-shirts the whole month, then it was back to winter.