Big Bear Lake experiences greater seasonality than the surrounding towns in the California's Inland Empire or Mojave Desert. While down in the flatlands, winters are warm and summers are sweltering, Big Bear experiences four distinct seasons.
While many people consider Big Bear and skiing to go hand in hand, the vast majority of winter snow on the mountain is probably man-made. Winter daytime temperatures can often get into the 50s, which makes snow short lived. Winter snowstorms can dump a foot or more of snow, but most snow events deposit just a few inches. However, about five feet of snow will fall over the entire winter, and cold snaps can bring daytime temperatures down into the 30s. Nighttime temperatures are generally below freezing, and when the sun disappears behind the mountains each evening, the town gets very cold, very fast.
Spring brings occasional rain and warmer daytime temperatures between about 60-70 degrees. The highest peaks can stay covered in snow until summer; so, while the pleasant daytime temperatures are great for hiking and mountain biking, you will want to ask around to find out where the snow line is. Although weather is generally pleasant, hailstorms, extended fog, and periods of high winds can occur throughout the spring. In May, trout fishing kicks off, and the high season lasts well into the summer. However, don't put on the swimsuits yet: even though you may be able to soak up some warm sunshine, the lake's temperature doesn't get above 60 degrees until June.
Summer days can get into the 80s, but you may still want a light sweater in the evenings. Hiking in the heat of day can be tough, especially above the tree line, but the days are much longer, which more than makes up for the hot sun. There are virtually no rainy days between the end of April and the beginning of November, so you will want to bring ample water on extended hikes, because many streams dry up during the summer. If you intend to spend time on the lake, wake up early to beat the crowds.
As summer fades into fall, the lake becomes too cold for swimming and the days get shorter. On the forested Western side of town, you will see more evidence of the changing season as the flowers fade and the leaves turn.
No matter what time of year you choose to visit Big Bear, you will encounter tourists. Weekend visitors flock from all over Southern California, and there are vacationers from all over the world. Weekdays are typically quieter than weekends, and holidays such as New Year's, Memorial Day, and the Fourth of July will pack Big Bear to capacity. The winter and summer months have the heaviest volume, and April, late August, and October are generally when the locals come out of their hiding places. Because of festivals and competitions in May, September, and February, certain weeks are more crowded than others. If you plan to visit in an "off" month, you might want to check to make sure that you haven't picked the weekend of Oktoberfest or the Trout Fishing Classic.
Big Bear's climate supports year-round outdoor activities, and its convenient location makes it popular for local tourists who want to escape from the desert life. Even though downtown can be overrun by tourists, and the lake can seem crowded with boats and jet skis, those who venture into the woods on foot, bike, or horseback will likely find solitude. So, go when the weather suits you, and if you encounter too many crowds, just make sure to take a little time away from the lake to recharge and enjoy the peace and quiet cherished by the year-round residents.