Two days ago in Santa Rosa it was close to 100 °F.
Yesterday it was just below 80 °F.
Today it's supposed to be about 73 °F
Normally, this is exactly what the weather around here does, though the changes are usually driven solely by coastal fog coming in & out to various degrees. This weekend it seems a low pressure system will be lowering the daily temps, but isn't forecast to cause any foul weather for us...
That fog effect - the lowering or moderating of the daily temps - is what gives the North Coast of California it's long maturation time on the vine, and maintains the higher acid levels which provide a better balance for the finished wines. Nighttime temps are usually found in the 50's when the fog's hanging off the coast, and in the low 70's otherwise, which gives the vines a good break to recuperate from the daily highs. That's a nice variation which you won't see anywhere in the Central or San Joaquin Valleys.
Sometimes it's a bit confusing to go from a tank top & shorts one day to a sweater and long pants the next, but it's better than being stuck with nothing but heat.