After delightful and distinctly autumnal cooling for a few days in late August – including a sub-freezing windchill recorded at San Jacinto Peak on Sunday 25th – temperatures are now forecast to rise and be well above seasonal in the first week of September (i.e. including the holiday weekend).
Thankfully temperatures in the high country have largely stabilized around seasonal averages since mid August, with air temperatures typically 50-55°F (10-13°C). Such temperatures feel pleasantly cool in contrast to the heat lower down the mountain, but they will actually be well above seasonal for the high elevations in the first week of September.
Hikers should continue to be prepared for hot weather on the trail system into the first week of September. Please give considerable extra thought to start times, route choice (considering sun exposure, forest cover, and water availability), appropriate clothing, sun protection, and hydration requirements.
Monsoon conditions can occur in late summer/early autumn, currently forecast as most likely on 7th-8th September, and hikers should always be prepared for the possibility of rapidly changing weather conditions in the high country. Thunderstorms with lightning, intense precipitation, and rapid temperature drops can occur, usually in the afternoon, even when such storms may not be forecast for lower elevations.
Survey hikes by the Trail Report every day year-round in the San Jacinto mountains include varied and often circuitous routes to San Jacinto Peak multiple times per week (55 days since 1st July), plus other trails on intervening days.
With a failed monsoon season (so far) and largely hot conditions for the past two months, fire risk is severe everywhere. A comprehensive fire ban is in place on Forest Service lands throughout the San Jacinto Ranger District (link to USFS order here) and in all Idyllwild campgrounds. Campfires are of course always prohibited throughout both the State Park and National Forest wilderness areas.
Fires are not a problem solely confined to our area of course. An article (linked here) published last weekend highlights the challenges faced by PCT hikers by the sheer number of fire closures along the entire trail route. Sadly it is debatable whether any PCT hiker has been truly able to complete the entire trail along its originally intended route in the past 10-15 years due to fire closures.
Major springs, creeks, and pipes continue to flow adequately at this time (example photos below). However flow rates are dropping steadily at all elevations and ephemeral water sources are now dry. The Round Valley faucet continued to flow well as of 30th August. In the Tahquitz area meadows, the minor creek in Skunk Cabbage Meadow continues to flow, but the ephemeral creek in Tahquitz Valley is now dry. Tahquitz Creek is flowing steadily at the northern end of Little Tahquitz Meadow, and near its source where it crosses the PCT at Mile 177. The creek at Strawberry Cienega is now functionally dry. Hidden Lake remained c.50% full in late August (by surface area, not volume).
Be rattlesnake aware. Above about 5000 ft elevation, the venom of Southern Pacific Rattlesnakes (Crotalus [oreganus] helleri) in the San Jacinto mountains is predominantly neurotoxic, almost always fatal for dogs and sometimes for humans (see my detailed 2020 article linked here for further information). Devil’s Slide Trail, lower Deer Springs and lower Marion Mountain trails, Suicide Rock, near Strawberry Cienega, and trails around Tahquitz Peak are frequent locations for sightings, but rattlesnakes have been recorded everywhere to 9350 ft.
Be bear aware. Although rarely reported in recent years, up to three Black Bears have been in the San Jacinto mountains since 2017. I have seen at least one annually for the past six years, most recently on upper Marion Mountain Trail on 14th September 2023. I also found fresh prints in snow on 12th February this year at 9000 ft near PCT Mile 180.5 (photo here). Brief videos from Devil’s Slide Trail in September 2021 (available here) and at home in Idyllwild in 2018 (linked here) show two different individuals. There have been no reports of negative interactions with humans at or near campsites.
The Palm Springs Aerial Tramway closes on Monday 9th September 2024 for annual maintenance, with a tentative reopening date of Monday 7th October.
WEATHER
Details of the many local records broken in an exceptionally warm July are given in a prior Report (linked here). So far this season there has been no significant monsoon rainfall, with precipitation in Idyllwild currently only 10% of average for the summer months.
A strong cold front brought early autumnal temperatures to the mountains on 23rd-26th August (the southern fringe of the same system that dusted extremely early snow on parts of the Sierra Nevada this past weekend). While August has averaged cooler than July, and despite a few pleasantly cool days recently, almost the entire month of August has had temperatures at or above seasonal. As is increasingly the case with a steadily heating climate in the San Jacinto mountains, overnight low temperatures in particular were well above seasonal throughout July and almost all of August.
Temperatures rose steadily on 26th-30th August to above seasonal yet again, and are now forecast to be far above seasonal for the first week of September at all elevations (although this will be most striking at mid elevations, e.g., Idyllwild area).
At San Jacinto Peak (3295m/10,810ft) on Friday 30th August 2024 at 0805 the air temperature was 54.3°F (12°C), with a windchill temperature of 47.1°F (8°C), 39% relative humidity, and a warm ESE wind sustained at 8 mph gusting to 14.4 mph.
At the Peak on Thursday 29th August 2024 at 0815 the air temperature was 50.8°F (10°C), with a windchill temperature of 41.5°F (5°C), 56% relative humidity, and a brisk SSE wind sustained at 10 mph gusting to 20.5 mph.
At the Peak on Sunday 25th August 2024 at 0740 the air temperature was 40.8°F (5°C), with a windchill temperature of 30.0°F (-1°C), 75% relative humidity, and a moderate WSW wind sustained at 8 mph gusting to 14.9 mph.
TRAIL CONDITIONS
Snow was completely gone from the high country trails by mid June.
The State Park announced closure of the uppermost section of Skyline Trail – which forms the lower part of the C2C (Cactus-to-clouds route) – in their jurisdiction, i.e. above about 5600 ft, on 12th July due to “dangerously high temperatures impacting the Palm Springs region”. The trail “will continue to be closed until further notice”.
Treefall hazards remain a major problem along parts of the Pacific Crest Trail, most notably between Antsell Rock and Red Tahquitz, with 132 recorded in my recent 2024 surveys between Miles 170.5-175.5. The disinterest of Forest Service and PCTA in maintaining this section of a world-famous trail for the past five years is unconscionable and embarrassing. Concentrations of large downed trees make for especially slow-going around Miles 170.5-172 (east side of Antsell Rock) and Miles 174-175 (south and east sides of Red Tahquitz). A further 15 smaller trees are down from Miles 168.5-170.5 (Spitler Peak Trail to Zen Center Trail).
About 12 treefall hazards on Deer Springs Trail include 8-9 in the upper trail that have been down and reported repeatedly for years but with no action from the State Park. All but one of the treefall hazards down between Strawberry Junction and the top of Marion Mountain Trail (roughly PCT Miles 183-185) were removed by the Trail Report in late June (example photos in an earlier Report linked here).
On Willow Creek Trail all treefall hazards on the Forest Service section were finally cut by 13th August. Whitethorn along the trail is starting to grow back rapidly, and is becoming a problem on both the Forest Service and State Park sections (photo in previous Report linked here). Forest Service made some progress on trail trimming on 26th-27th August. Treefall hazards currently on the State Park side include two large ones remaining from last year, plus three small new ones, but none pose major problems for hikers, and some may be removed in September.
The 34 treefall hazards that came down across Spitler Peak Trail during ice storms in February 2024 were almost all cleared by the Trail Report on 14th June. The couple of minor stepover branches that remain pose no problem for hikers. This work brings to 120+ the total number of trees removed by the Report from this trail in the past three years. Note that currently the upper trail in particular is heavily overgrown with lush seasonal vegetation.
The Caramba Trail from near Reeds Meadow through Laws Camp and on to Caramba, and the Cedar Trail from Willow Creek Trail to Laws, are euphemistically described by the Forest Service as “not maintained”. In reality both trails have been abandoned and functionally no longer exist. They are so heavily overgrown with dense whitethorn, which obscures dozens of downed trees, that I strongly advise hikers do not attempt to follow them (regardless of how much you may trust an app). An informal use trail to Laws is much more direct, maintained, and avoids the challenging bushwhacking of the unmaintained trails (local Idyllwild hikers dubbed it the “King Trail” when I established the route in 2019). It leaves Willow Creek Trail exactly 1.0 mile from Saddle Junction, 0.46 mile from the Skunk Cabbage turning (trailhead at N 33.7796, W 116.6590). The route descends largely following established deer trails for 1.2 miles, meeting Willow Creek about 0.2 mile upstream from the site of the historic Laws Camp (the remains of which were destroyed by the 2013 Mountain Fire and subsequent flood and treefall damage). Eleven trees down on the King Trail were removed in June-July 2023. The tread of the trail received some damage from Tropical Storm Hilary last year. From Laws east to Caramba the route of the original Caramba Trail has been well-cairned by myself and others and can largely be followed with very careful route-finding. My 2023 survey counted about 110 trees down on this 2.1 miles of trail. It is especially obscure for the first 0.3 mile east of the Willow Creek crossing, becoming more obvious (but still subtle) as it descends towards Caramba. Very cautious navigation is advised throughout the area.
The Trail Report “adopted” Seven Pines Trail as a priority for maintenance work as the trail had a disproportionate number of lost hiker rescues in the past decade, and both State Park and Forest Service have shown no interest in maintaining the route for years. Since 2020 we have removed 75 downed trees and the trail is thoroughly trimmed and cleared multiple times annually. As of July 2024 the trail is largely clear of treefall hazards, with three down across the trail in its upper section, all easily passable for hikers. A further half-a-dozen downed trees close to the PCT junction would need to be removed to fully restore the original route of the trail. Although the condition of the trail is hugely improved, Seven Pines remains a genuine wilderness trail unlike the wider, bare, obvious routes of, for example, Devil’s Slide or Marion Mountain trails. Cautious navigation remains essential for those without considerable experience of hiking this trail. Be aware in particular that Seven Pines Trail becomes most obscure in the mile closest to its junction with Deer Springs Trail/PCT.
The Zen Center Trail continues its deterioration that started following the 2013 Mountain Fire, with a combination of vigorous regrowth and treefall hazards further obscuring the route with each passing season. The lower and upper parts of this trail are partially cairned and not too bad for those who are very familiar with the former route, but even the experienced find navigating the central section tricky. Long trousers, scrambling gloves, and an enjoyment of bush-whacking are all strongly recommended.
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San Jacinto Trail Report 
appreciate your clear photos of water flow Jon, thank you.
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