Sunrise / Sunset / UV 2000
Date Sunrise Sunset Length of Daylight High UV times January 1 6:58 4:54 9:56 -- -- January 15 6:58 5:06 10:08 -- -- February 1 6:50 5:23 10:33 -- -- February 15 6:37 5:37 11:00 -- -- March 1 6:21 5:49 11:28 -- -- March 15 6:03 6:00 11:57 10:30 1:30 April 1 5:40 6:14 12:34 10:00 2:00 April 2 6:38 7:14 12:36 11:00 3:00 April 15 6:21 7:24 13:03 10:30 3:15 May 1 6:03 7:37 13:34 10:15 3:30 May 15 5:51 7:48 13:57 10:00 3:40 June 1 5:42 7:59 14:17 10:00 3:45 June 15 5:40 8:06 14:26 10:00 3:50 July 1 5:45 8:08 14:23 10:00 3:50 July 15 5:52 8:05 14:13 10:00 3:50 August 1 6:04 7:53 13:49 10:10 3:45 August 15 6:14 7:39 13:25 10:30 3:30 September 1 6:26 7:18 12:52 10:40 3:05 September 15 6:36 6:59 12:23 11:00 2:30 October 1 6:47 6:36 11:49 11:30 1:50 October 15 6:58 6:18 11:20 -- -- October 28 7:09 6:03 10:54 -- -- October 29 6:10 5:02 10:52 -- -- November 15 6:26 4:49 10:23 -- -- December 1 6:40 4:43 10:03 -- -- December 15 6:51 4:45 9:54 -- --
December - March This is one of the most delightful times of the year to hike the lower elevations, as long as a winter storm is not in progress. Temperatures are usually pleasant and the bugs are gone.
It's the rainy season. The peak rainfall months are January - March, followed by December. Check the forecast for rain and snow predictions. Current total rainfall and the rainfall for the last four years for Fallbrook is highly correlated with the rainfall in Pasadena. Higher elevations receive higher rainfall.
The water level in canyons can rise much faster than you realize, and people have died from floods while hiking. Don't hike if it might rain unless you know how to evaluate the safety of the area you are hiking in for flooding. Many people have had to be rescued because they couldn't cross creeks that suddenly became swollen and dangerous.
Snow may fall at elevations above 3000 - 8000' during any given storm, and quickly make your trail disappear, which could be followed by your own permanent disappearance unless you know how to handle such conditions. See snow level vs. time for previous years. Chains are often required on most roads above 5000' during storms. Patches of snow can survive in shaded locations to lower altitudes.
Hiking season in the high country is over until May or June unless you love low temperatures, ice and snow. Angeles Crest Highway between Islip Saddle and Vincent Gap is closed for the season, so you cannot drive to trailheads within the closed section such as at Buckhorn Campground. If you do hike in the high country from other trailheads, be prepared for cold temperatures. Average temperatures have now reached their minimum values, and will stay in the same low range until April or May. Note the large variability in maximum temperatures at higher altitudes - the high at Mt. Wilson can be anywhere from 30 to 70°, and temperatures can plummet quickly when a front comes through.
Watch for problems on trails due to the latest storms, such as slides on the trail, slippery footing, etc.
Bugs are finally gone, but ticks have emerged.
Roads near recent burn areas are often closed due to mudslides, such as SR39 being closed on 2/21/00 at the entrance to San Gabriel Canyon, with another mudslide at the East Fork Road.
March - April It's getting close to the end of the rainy season, but significant rain is still expected in March with lighter rain in April.
Bugs usually aren't bad until June, but in 1997 they were bad starting in March.
April is the usual start of the smog season, so check the smog forecast before hiking in mid-day.
Roads near recent burn areas are often closed due to mudslides, such as SR39 being closed on 2/21/00 at the entrance to San Gabriel Canyon, with another mudslide at the East Fork Road.
May The rainy season is essentially over now, so no significant rain is expected until late Fall. The record latest snowfall at Mt. Wilson is 1.5 inches on June 16, 1995. Check the forecast for rain and snow predictions if we get a late storm.
Hiking season in the high country has begun again, and you can revisit early spring at lower elevations by going there. However, Angeles Crest Highway between Islip Saddle and Wrightwood is still closed, so you cannot drive to those trailheads. Check current conditions to see when the road has been reopened.
Average mountain temperatures are now warming up. Until ~June 1, the maximum temperatures at higher altitudes still show large variability - the high at Mt. Wilson can be anywhere from 40 to 80°, and temperatures can plummet quickly when a front comes through. After ~June 1, the maximum temperatures at Mt. Wilson are reliably in the 70s and 80s, with high temperatures at 9000' in the 60s and 70s.
Bugs usually aren't bad until June, but in 1997 they were bad starting in March.
It's the smog season, so check the smog forecast before hiking in mid-day.
Same as May except SR2 is now open.
June Most of the snow and ice was gone by 5/28/01 except in a few protected places, and even most of that was gone by 6/15/01.
Bugs have started to make hiking miserable in many places, unless you keep moving at all times.
It's the smog season, so check the smog forecast before hiking in mid-day.
July - August The rainy season is over now, so no significant rain is expected until late Fall. However, when the monsoons reach the San Gabriels in July or August, localized thunderstorms are possible. In addition, an average of one day of rain from hurricane remnants occurs sometime in August or September.
Snow is completely gone.
Lower elevation trails below ~6000', such as the Condor Peak Trail, have become "foxtail heaven", as Roy Randall puts it, and either wear protection such as gaiters for your socks or be prepared to spend a lot of time picking out foxtails. Higher elevation trails above ~6000', generally are free from annual grasses.
Hiking season in the high country is in full swing, with plants in bloom there now that long ago finished at lower elevations. Jane Strong and Dave Anderberg report that Angeles Crest Highway between Islip Saddle and Wrightwood is open.
Unfortunately, July and August are among the worst times to hike the San Gabriels for three reasons:
- Bugs are in full force, with mosquitoes, black flies and biting snipe flies making it impossible to stop in many locations;
- Temperatures are often high at nearly all altitudes. Thanks to the inversion layer and the absence of ocean influence, temperatures at 5000 - 8000' can be nearly identical to temperatures in Pasadena. The monsoons can make it humid as well.
- It's smog season, and the mountains can be just as smoggy as the basin. Worse, even air qualities of 50 for ozone, at the boundary between good and moderate quality air, can affect people doing extended strenuous exercise, such as hiking. If you breathe deeply after a hike, and then have to cough, you've been smogged and have temporarily lost significant lung capacity. Check the smog forecast before hiking in mid-day.
September - October A thunderstorm from a monsoon or rainfall from hurricane remnants can occur in September, and the rainy season starts in October, so storms may occur at any time now. An average of one day of rain from hurricane remnants occurs sometime in August or September. However, these are still very light rainfall months, so few rainy days are expected. However, check the forecast for rain and snow predictions.
The water level in canyons can rise much faster than you realize, and people have died from floods while hiking. Don't hike if it might rain unless you know how to evaluate the safety of the area you are hiking in for flooding. Many people have had to be rescued because they couldn't cross suddenly-swollen and dangerous creeks.
Snow may fall at elevations above 3000 - 8000' during any given storm, and quickly make your trail disappear, which could be followed by your own permanent disappearance unless you know how to handle such conditions.
Last winter's light rainy season has not caused essentially any new problems for the trails, so they remain in pretty good condition overall. Ted Finamore reports that only a single fallen tree that was easily negotiated mars the entire Gabrielino Trail.
Lower elevation trails (below ~6,000'), such as the Condor Peak Trail, are probably still "foxtail heaven", as Roy Randall puts it, and either wear protection such as gaiters for your socks or be prepared to spend a lot of time picking out foxtails. Higher elevation trails (above ~6,000') generally are free from annual grasses.
Hiking season in the high country is about to finish, with temperatures falling rapidly. The Angeles Crest Highway closes between Islip Saddle and Vincent Gap (sometimes farther east) with the first snowfall, usually sometime in October through December, eliminating access to a number of trailheads.
However, Santa Ana wind conditions, accompanied by extreme heat and high fire danger, often occur in September and October. So these are months to pay attention to the weather before starting on a hike.
Bugs are still present in places, although usually much-reduced from their number earlier.
It's still the smog season through October, so check the smog forecast before hiking in mid-day. Remember, the mountains can be just as smoggy as the basin. Worse, even air qualities of 50 for ozone, at the boundary between good and moderate quality air, can affect people doing extended strenuous exercise, such as hiking. If you breathe deeply after a hike, and then have to cough, you've been smogged and have temporarily lost significant lung capacity.
November This is one of the most delightful times of the year to hike the San Gabriels at any elevation, as long as a winter storm is not in progress. Temperatures are usually pleasant and the bugs are mostly gone.
The rainy season will begin soon. Check the forecast for rain and snow predictions. Current total rainfall and the rainfall for the last four years for Fallbrook is highly correlated with the rainfall in Pasadena. Higher elevations receive higher rainfall.
The water level in canyons can rise much faster than you realize, and people have died from floods while hiking. Don't hike if it might rain unless you know how to evaluate the safety of the area you are hiking in for flooding. Many people have had to be rescued because they couldn't cross creeks that suddenly became swollen and dangerous.
Snow may fall at elevations above 3000 - 8000' during any given storm, and quickly make your trail disappear, which could be followed by your own permanent disappearance unless you know how to handle such conditions. See snow level vs. time for previous years. Chains are often required on most roads above 5000' during storms. Patches of snow can survive in shaded locations to lower altitudes.
Hiking season in the high country will end in a month or two until May or June unless you love low temperatures, ice and snow. Angeles Crest Highway between Islip Saddle and Wrightwood will be closed for the season when the snow starts falling. Average temperatures are close to their minimum values, and will stay in the same low range until April or May. Note the large variability in maximum temperatures at higher altitudes - the high at Mt. Wilson can be anywhere from 45 to 70°, and temperatures can plummet quickly when a front comes through.
Watch for problems on trails due to the latest storms, such as slides on the trail, slippery footing, etc.
Roads near recent burn areas are often closed due to mudslides, such as SR39 being closed on 2/21/00 at the entrance to San Gabriel Canyon, with another mudslide at the East Fork Road.
Go to:
Copyright © 1997-2003 by Tom Chester.
Permission is freely granted to reproduce any or all of this page as long as credit is given to me at this source:
http://tchester.org/sgm/conditions/trails_by_month.html
Comments and feedback: Tom Chester
Last update: 7 January 2003.