One cynical writer stated some years back that there are 4 seasons in L.A.—fires, earthquakes, floods and riots. There really are seasons, but they are more subtle than what you’ll find in Omaha.
Summer in Southern California
Summer seems to get the most attention; it can be 90+ degrees but the humidity is typically fairly low so you can handle it much better than in more humid areas of the country. It cools down in the evenings, especially when we get an ocean breeze.
It may be that you are not working on summer travel plans, but expect to visit at another time of year.
Fall in Southern California
In the Fall, we can still have some very warm days, but it will tend to cool down much more at night.
This is when you hear about the brushfires, because the weather is dry and hot for days at a time, and we haven’t typically had any meaningful rain since April.
This can even be a better time to visit Southern California than during the summer travel season, because after Labor Day much of the tourist traffic is gone but the weather is still great.
Winter in Southern California
By November the days and nights are cooler and we may start to get real rain by Thanksgiving. Although a lot of the trees are evergreen, we do see leaves turn color. We don’t usually get the sub-zero cold snap that really fires up the colors.
The rainiest months are January through April. The bare trees, cooler weather, shorter days (sun lower in the sky) and snow visible in the nearby mountains make it a very nice time of year. We actually get some pretty cold winter weather at times, with lows below freezing and highs in the 50s. If you’re from Hawaii that’s really cold. If you’re from Buffalo you’re scoffing at such temperatures being called low.
Spring in Southern California
The main reason we never get snow at sea level is that the air warms up when the sky becomes overcast; the only time it’s cold enough for snow is when it’s very clear. Springtime can give us cool weather, or may result in a heat wave of 100+ degree weather; and we could have both extremes in the course of a week. There’s a lot of spring skiing that goes on in the San Bernardino Mountains.
May is a good month, as the weather is almost always either great or OK, and it’s not yet tourist season. The ocean temperature does not warm up until June or July, but may stay warm well into September. So if you have a choice, and ocean activities are your primary interest, you might want to shoot for early September rather than earlier in the summer travel season. You’re likely to get better prices then also at L.A. basin and San Diego attractions. The bottom line is that SoCal is a great place to visit year ‘round.