"To be interested in the changing seasons is a happier state of mind than to be hopelessly in love with spring."
you don't like the weather, wait ten minutes. It can change
that often, or it seems like it. The weather can also vary
significantly from one area of the peninsula to another. It may be
sunny and clear in Carmel, while five miles away it will be cold and
foggy in Monterey. Or vice-versa. Usually the fog clears earliest in
Carmel, comes in latest to Monterey, and often lingers all day in
Pebble Beach and Pacific Grove.
To accommodate the frequent temperature changes, wear several layers that you can put on and take off as needed. In the summer, always carry a sweater.
Contrary to your intuitions, the warmest months are May and September, just before school gets out, and just after it starts again. Cruel, no? Temperatures during these two months can get into the 70s or 80s during the day, and lows tend to be in the mid 50s. October is almost as nice, reaching highs in the 60s or 70s and occasionally into the 80s. Lows then are a bit chillier ranging from about 45-50.
The coldest months are December, January, and August (only half kidding, for August is the foggiest summer month). Winter highs can be anywhere from the 50s to the 70s and lows are usually in the low to mid 40s. On rare occasions, usually in late December or January, lows can get below freezing. Summer temps are fairly consistent, with highs ranging from about 65-75, and lows almost always around 55. However, be advised that these numbers can be deceiving. The air here is very damp, and when it gets cold, it feels about ten degrees colder. 40 here feels like 30 anywhere else.
Spring and Fall can be fickle. The days could be sunny and warm or stormy and blustery. It's not unheard of to experience both extremes within a two day period. That's one of those things that makes life here so enjoyable. Springtime also has a tendency to be quite breezy, so a light jacket is recommended. So are kites.
The prevailing winds are from the west. But every now and then the winds will come from the east, a situation known as "offshore flow," creating unusually warm and dry conditions. It never lasts more than a couple of days.
There's no such thing as bad weather on the Monterey Peninsula. Sun is always nice, but a bit monotonous after awhile. Of course, Monterey is well known for the fog that rolls in almost every summer afternoon to keep things cool. Whatever you do, don't complain about the fog!!! We love our fog. It keeps us from getting too hot, and we think it is pretty drifting through the Monterey Pines and tumbling over the hills. If you're looking for warm summer sun, we advise you to pick one of California's inland travel destinations.
Typically, our rainy season runs from mid October into April. When it rains here, it really rains. Then it clears up. This is the best time to venture out and explore. Colorful, billowing clouds begin to break up as sunbeams dive between them, shooting golden rays into the sea. In the forests, trees and shrubs saturated with water have richer, more vibrant colors. Summer tourists miss all the glory.
Our winter storms provide awesome sights. The winter surf blasting on the shoreline is spectacular and humbling. Fair weather tourists miss all of the excitement.
Mr Toy's favorite atmospheric condition of all is the full moon. If you happen to be here during the peak of the lunar cycle, go to the beaches. Visit those in Carmel or Pacific Grove, which are away from glaring lights. Don't bother taking a flashlight. A walk in the moonlight is good for you and your love life. Sun worshipers miss the romance.
Bottom line: If you have a sense of wonder and adventure, you'll enjoy the weather here at any time of year. But if you're looking for the picture-postcard perfect weather shown in California travel brochures, you're liable to be disappointed.