Lakeside, CA in December: Weather, Daylight and What’s in Season

What December is like in Lakeside

Lakeside sits inland in East County San Diego, and December brings a real swing between warm afternoons and cold nights. The nearest long-term NOAA climate station is in El Cajon, next door, and its 1991-2020 normals give a clear picture of the month:

• Average high: 68.5°F. Most afternoons are T-shirt or light-sweater weather in the sun.
• Average low: 41.7°F. Mornings and evenings are cold.
• Nights at or below 40°F: about 14 in an average December.
• Nights at or below freezing: about one in an average December, so frost is possible but rare.
• Rain: 1.83 inches in an average December, with about four days of a tenth of an inch or more.

Short days: sunrise and sunset in December

December has the shortest days of the year, and that shapes everything from hikes to holiday evenings. U.S. Naval Observatory figures for Lakeside in 2026:

• December 1: sunrise 6:32 am, sunset 4:41 pm.
• December 12: sunrise 6:41 am, sunset 4:42 pm.
• December 21, the winter solstice week: sunrise 6:46 am, sunset 4:45 pm.
• December 31: sunrise 6:50 am, sunset 4:52 pm.

Planning around the light

Sunset barely moves through the first half of December, staying around 4:41 pm, while sunrise keeps getting later. Civil twilight ends roughly 27 minutes after sunset, so it is properly dark by about 5:10 pm. Plan to be off the trail by mid-afternoon, and expect the temperature to drop quickly once the sun goes behind the hills.

County parks run on that clock too. El Monte County Park opens to vehicles at 9:30 am and closes at sunset, and El Capitan County Preserve opens at 8 am and closes at sunset, so a 4:40 pm sunset is a hard stop.

In season: trout fishing at Lake Jennings

Winter is trout season in Lakeside. Lake Jennings says its trout stocking season begins around November and runs through early April, with trout caught into June in typical years. That makes December one of the best months to bring a rod.

Before you go, get a California state fishing license, which the lake does not sell, and buy a Lake Jennings fishing permit at the campground check-in station. Day use and shore fishing are open 8 am to 5 pm daily. Fishing and boating hours run 6 am to midnight on Fridays and Saturdays, with the entrance gate closing at 10 pm, and 6 am to 7 pm on Sundays.

In season: cool-weather hiking

The hikes that are punishing in summer are at their best in December. El Capitan County Preserve, at 13775 Blue Sky Ranch Road, has about 11 miles of trail along a granite ridgeline with views of three reservoirs, the ocean and the mountains. The county calls the full hike strenuous, says it can take up to six hours, and warns there is very little shade. It closes every August for heat, which tells you why winter is the time to do it. Start at the 8 am opening so you finish well before sunset.

For something gentler, the Historic Flume Trail at El Monte County Park climbs the hillside to the route of the San Diego Flume, with interpretive panels along the way, and the Helix Flume Trail about a mile west adds valley views. Day-use parking at El Monte is $5.

In season: winter birding at Lindo Lake

Lindo Lake County Park, in the middle of town at 12660 Lindo Lane, is one of San Diego’s few natural lakes, and winter is a good time for waterbirds. Palomar Audubon Society’s walk there on December 5, 2015, logged 66 species, including Bufflehead, Green-winged Teal, Ruddy Duck, Wood Duck and Greater White-fronted Goose. The society’s New Year walk on January 4, 2026, rescheduled after the December outing was rained out, found 65 species, among them a Black-throated Green Warbler, which it called a rare winter visitor.

The park is open sunrise to sunset and has 1.5 miles of ADA-friendly trails. The county expects construction on the lake’s west basin to begin in fall 2026 and finish by winter 2027, so check the county parks website for any closed areas before you bring binoculars.

A rainy-day option: the Lakeside Library

If a storm rolls through, the San Diego County Library’s Lakeside branch at 12428 Woodside Avenue is an easy indoor stop. It is open Monday 10 am to 6 pm, Tuesday noon to 7 pm, Wednesday and Thursday 10 am to 6 pm, and Friday and Saturday 10 am to 5 pm, and closed Sundays. Its December 2026 calendar includes a Kamishibai storytime on December 3 and a Sugar Plum Fairy Ballerina Storytime on December 10, both at 10:30 am.

What to wear in Lakeside in December

• Layers: a T-shirt or light top for a 68°F afternoon, plus a warm jacket for the 40s after dark.
• A hat and gloves if you will be out after sunset or early in the morning.
• Sun protection for midday hikes; El Capitan has little shade even in winter.
• Closed shoes or boots that can handle damp grass and muddy trails after rain.
• A packable rain shell. Rain is not frequent, but a December storm is always possible.

Holiday happenings and closures

Lakeside’s own holiday celebration is the Lakeside Chamber of Commerce’s free Spirit of Christmas on Saturday, December 5, 2026, from 3 to 7:30 pm on Maine Avenue, with a community tree lighting at 5 pm. The same weekend, and again on December 12-13, El Monte County Park hosts the Yuletide Medieval Festival, a ticketed living-history event set in England in 1420.

On Christmas Day, El Monte County Park and El Capitan County Preserve have no public vehicle access or restrooms. The county parks website also carries storm-recovery notices with current closures, so check it before any trip that depends on a trail.

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