Weather and trail update 19th January 2021

[UPDATE 20th January: wild Santa Ana winds over the past 24 hours have been accompanied by light precipitation. Based on our hike this morning, snow settled above 7000ft (0.5 inch) with about 1-2 inches above 8000ft. Drifting may be extreme in places due to the very strong winds. Trail condition information below may no longer be strictly accurate. Carrying spikes is recommended everywhere above 7000ft at least. The next storm systems, bringing much more snow, are forecast for Saturday and Monday.]

A remarkable sequence of weather conditions so far in January 2021 is forecast to get even more unusual in the next few days. Details are below – see Weather – but cold Santa Ana (north-east) winds tomorrow will briefly bring critical fire weather conditions, but may also draw up light precipitation from the south. The following 7-10 days will be cold and very unsettled, with precipitation possible on multiple days, more conventionally from the west. In contrast, the overnight low temperature in Idyllwild a couple of days ago was 30 degrees above seasonal.

My ascent of San Jacinto Peak yesterday morning was almost as fast as a typical summer hike, on a largely clear trail with only a few extended sections of firm ice and icy snow, up and down the east side trails via Devil’s Slide (with no spikes required ascending, but useful in a couple of spots for descending). Melting of the snow that fell on Monday 28th December was rapid in the past week, on sun-exposed slopes at all elevations, and more widely below about 8500ft, as described in detail below.

The Bonita Fire on 15th January was successfully held at about 715 acres. May Valley Road and the western section of Bonita Vista Road are closed (as are all associated side trails). As I watched multiple ‘planes drop retardant near May Valley Road with a snow-covered Thomas Mountain as a backdrop, it was abundantly clear to me that regrettably we no longer have a “fire season”. The accelerating and dramatic changes to our mountain climate in the past decade, with associated (and long-term) declines in forest health, can produce critical fire conditions year-round, even in mid-January. Also, when conditions get bad enough, the supposed “fire break” effects of past fires simply no longer exist. Some of what burned in the Bonita Fire had also burned in the Cranston Fire just 30 months earlier, and almost everything else had previously burned in the 2013 Mountain Fire (with some meadows burning in all three fires!). Sobering indeed.

Major trails have largely been traveled since the last snowfall in late December, and conditions are discussed below for specific trails where known. Melting has been rapid in the past week. In addition to those, there are posthole tracks around the Tahquitz area meadows on Willow Creek and Caramba trails, to Chinquapin Flat and to Tahquitz Peak. Snow depths measured today are listed at the foot of this posting.

Spikes remain recommended for some sections of all trails above about 8000ft (see trail-specific details below), especially for descending, as established trails are now generally well consolidated by hiker traffic and freeze-thaw cycles. Spikes may be useful locally at lower elevations also. Snowshoes are useful only for extended off-trail travel above about 10,000ft on sheltered slopes (that may change depending on snowfall over the next week or so).

With unsettled weather forecast for the remainder of January, hikers should be prepared for temperatures below freezing in the high country, and potentially far below freezing when considering wind chill effects (see below for temperatures recorded recently at San Jacinto Peak).

All developed and yellow post camping is closed in the San Jacinto Ranger District of the San Bernardino National Forest. This was initially due to exceptional fire risk, but more recently due to the coronavirus crisis. All camping is prohibited in Mount San Jacinto State Park, where the four wilderness camping areas in the State Park remain closed (camping is not permitted elsewhere in the State Park). Wilderness camping appears to now be permitted in the National Forest. See the State Park or Forest Service websites for further information.

Due to the coronavirus crisis Mount San Jacinto State Park is encouraging visitation to be confined to local residents only. The Idyllwild ranger station of the State Park has again closed (the U.S. Forest Service ranger station in Idyllwild has not reopened since March 2020). Day use permits are nevertheless required for the San Jacinto wilderness, and should be available at the self-serve kiosks outside either ranger station.

The USFS gate at Humber Park is closed. There is legal parking for nine vehicles just below the gate. On recent weekends (and some weekdays) the uppermost 0.1 mile of Fern Valley Road has also been closed at its junction with Forest Drive. Although parking is normally legal along Forest Drive, CHP has towed vehicles that were parked along that street at weekends. Use discretion when parking in this area on weekends/holidays. The gate on South Ridge Road is also closed.

Palm Springs Aerial Tramway closed again starting 12th December 2020 due to the coronavirus crisis, with no tentative reopening date at this time.

WEATHER After temperatures far above seasonal last week, with rapid snowmelt at all elevations, the remainder of January will be cold, unsettled, and with possibilities for precipitation. Very strong Santa Ana winds are forecast on 19th-20th. These will be associated with cold air (unlike the Santa Anas involved with the Bonita Fire last Friday). Light to moderate storm systems are forecast off-and-on for the remainder of the month, with snow currently possible on several of the next 14 days in the San Jacinto high country. Currently significant snowfalls are forecast centred around Saturday 23rd, Monday 25th, and Friday 29th January.

An excellent video discussion of the complex weather situation for the next few days was released this afternoon by NWS San Diego.

At San Jacinto Peak (10,810ft/3295m) on Monday 18th January 2021 at 0835 the air temperature was 30.1°F (-1°C), with a windchill temperature of 20.4°F (-6°C), 41% relative humidity, and a brisk NNE wind sustained at 7 mph gusting to 8.9 mph.

At the Peak on Monday 11th January 2021 at 0855 the air temperature was 24.6°F (-4°C), with a windchill temperature of 4.4°F (-16°C), 46% relative humidity, and a bitter NNE wind sustained at 25 mph gusting to 30.1 mph.


Almost all trails are now only partially snow-covered. Most areas below about 8600ft have only patchy snow, with most trails below 7500ft clear or largely clear. Sun-exposed slopes in particular, even at the highest peaks, are largely clear of snow. Reliable tracks are now in place for most major trails including: Devil’s Slide, Deer Springs, Marion Mountain, Peak, Wellman, South Ridge, Tahquitz Peak, and the Tahquitz area meadows. Conditions may well change soon with dustings or light snowfalls possible on several days in the next week. Cold conditions for the foreseeable future will result in firm ice and icy snow on trails, which becomes more hazardous if it is covered with a thin layer of fresh snow.

Tahquitz Peak trail from Chinquapin Flat/PCT Mile 178 has steps to follow through the angled icy snow. These icy slopes are treacherous. Spikes are strongly recommended. Snowshoes are not advised due to the angle of the icy snow, even if there is a light covering of fresh snow in coming days.

Devil’s Slide Trail is largely clear of snow to 7600′ with a few extended icy snow patches. Snow is patchy but more continuous above that elevation, becoming almost continuous near Saddle Junction. The trail is hard and icy and spikes can be useful for descending. The major new treefall hazard just past the seventh and eighth switchbacks was being cut today by our great volunteer USFS trail crew.

Deer Springs Trail is basically clear of snow up to Strawberry Junction at 8100ft (spikes not required to this point). From Strawberry Junction to about 8600′, 0.2 mile before the Marion Mountain Trail junction, snow cover is very patchy. Snow is more continuous from there to San Jacinto Peak, but with significant cleared sections on sun-exposed slopes. Above Little Round Valley the posthole track through the snow does not follow the trail route to San Jacinto Peak, and is steep and direct, but is adequate. Spikes are very useful, especially for descending, as snow is icy and compacted.

Marion Mountain Trail has very limited patchy snow to 7500′ (no spikes required for ascending). There some extended patches of snow from there to the PCT/Deer Springs Trail junction. Spikes are useful, especially for descending.

Fuller Ridge Trail has not be traveled since the last snow (late December) and there are no tracks to follow.

Seven Pines Trail has had no hiker traffic since the most recent snowfall, with no tracks or trail to follow. Indeed this trail has been hiked very little since November 2018. Extremely cautious navigation is recommended for those who are not very familiar with hiking this trail. The Forest Service closure of Dark Canyon Road continues, and there is no vehicular access to Seven Pines trailhead.

The Wellman and Peak trails have less than 50% snow cover, and there is a well-defined and (largely) accurate track to follow through the sections of icy snow.

The Ernie Maxwell Trail is basically clear of snow.

South Ridge Trail is largely clear to Old Lookout Flat at 7600′. Snow cover is significant on the traverse from there to the start of the switchbacks (at about 7900ft), The 18 switchbacks to Tahquitz Peak are largely clear except where they are north-facing and receive little direct sun. Spikes are useful, especially for descending. South Ridge Road (closed) is largely clear of ice, with a few small patches remaining.

SNOW DEPTHS measured on 18th January 2021 as follows (with comparison to 29th December 2020 where known). Note that average depth is given; depths are very variable now due to differential melting in exposed areas, and to strong winds that caused extensive drifting. Altitudes are approximate.

San Jacinto Peak (10810′): 6 inches (17 inches on 29th December 2020)

Wellman Divide (9700′): 3 inches (15 inches on 29th December 2020)

Annie’s Junction/approx. PCT Mile 181.8 (9070′): 6 inches (15 inches on 29th December 2020)

Strawberry Junction (8100′): <1 inch

Saddle Junction/approx. PCT Mile 179.9 (8070′): <1 inch (16 inches on 29th December 2020)

Devil’s Slide Trail at Humber Park (6550′): <1 inch (14 inches on 29th December 2020)

The Peak Trail at 9800ft just above Wellman Divide on 18th January 2021 (above) and the same view on 31st December 2020 (below).

San Jacinto Trail Report: available for everyone, funded by readers. While all labor and time is volunteered, this Report completely depends on small private donations to cover its costs. In an especially challenging year, and with a busy winter already well underway, every contribution is invaluable. If you have found this Report useful, please consider visiting the Donate page. Thank you.

3 thoughts on “Weather and trail update 19th January 2021

    1. Thanks Dan. On either a ‘phone or laptop as you start to scroll down the home page, a small pop up should appear in the lower right that says Follow. From this prompt you can sign up to receive email updates whenever I post them.


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