Mammoth Mountain Weather
Updated Monday, December 29th, at 7 AM
Next Update around 3 PM on Tuesday
Expect clear skies today, and then on Tuesday, a few high clouds with continued light winds in the area.
Temps will be in the mid-30s at Main Lodge, then rise into the low 40s Tuesday into Wednesday. Overnight lows will be in the teens tonight and the lower thirties on Tuesday night.
Main Lodge winds today will be NE at 5 to 10 mph with gusts to 20 MPH. On Tuesday, the wind is from the NE 5 to 10 mph.
Winds over the higher elevations today will be NE at 15 mph, with gusts up to 25-35 mph. On Tuesday, more NE winds at 10 to 15 mph with gusts to 25 mph at times.
Starting on Wednesday, the next series of storm systems will begin moving into the Mammoth and Eastern Sierra regions with very light rain and snow likely.
The first system in this series will be a warm Baja Cut of Low that is moving northeastward with subtropical moisture.
This low appears to have only light moisture on Wednesday, with snow levels at 9,000 to 9,500 feet.
Satelight View
Radar View
Mammoth WX Discussion
12-29-25 @ 8 AM – Here is the full story on this Monday Morning: a transient ridge of high pressure is building into the area and will peak overhead on Tuesday. At the same time, a piece of energy from the Christmas system has pinched off, forming a cut-off, or what we now call a Baja Low to our SW.
Over the next few days, the ridge will continue to slide east while the Baja Low begins to lift northward as the next low drops in from the north.
By Wednesday, the cut-off low slowly starts to move northwest into Central California. As this happens, the low will push some subtropical moisture toward us, increasing the chance of light rain and snow showers by sunrise on Wednesday and continuing through New Year’s Day.
This initial wave of moisture will bring high snow levels on Wednesday, rising from around 9,000 to 9,500 feet, possibly higher for a time, Wednesday afternoon into the overnight hours.
Precipitation on Wednesday will be light, with less than a quarter inch of water expected to move through the area. By New Year’s Day, the upper half of the hill could have 1-2 inches of new wet snow.
On New Year’s Day, snow levels are expected to drop to around 8,300 to 8,800 feet. With 3-6 inches of fresh snow from the Main Lodge to the Top by late Thursday night.
By late Friday, the northern low will be moving in with colder air, and snow levels will drop to 6,000 to 6,500 feet. Moisture increases during this period, and there is potential for more productive snowfall late Friday night into Saturday afternoon with light snow showers into Saturday night.
The Friday Night/Saturday storm looks like a solid foot in the Powder Fields of Mammoth Mountain, so that one would be an excellent refresher for the snow surface after the warm system comes through mid-week.
Here is today’s GIF showing you what I’m looking at this morning.
After the weekend system, there is a break, with the next low out at day 8, and then again in the ultra-long range around Jan 10th.
Here is the QPF this morning out 10 days: perfect amounts for great skiing without massive shutdowns for days.
Now that we have the base, all we need are some nice, cold refresher storms for freshies and packed powder.
I will keep you updated on what to expect…
Ski Ya Later,
Snowman
❓ Top Mammoth Weather Questions (from the Snowman)
When does Mammoth usually get its first snowfall?
Light snow can fall in late September, but consistent snowfall usually begins in late October or early November. Opening Day typically lands between November 10 and Thanksgiving, depending on storm activity and snowmaking.
How does the ENSO pattern affect Mammoth’s late fall and winter weather?
ENSO (El Niño/La Niña) plays a big role in Sierra storm patterns. El Niño winters often bring warmer, wetter storms. La Niña typically favors colder, backloaded seasons with more snow from February through April. Neutral years are the wildcards with high variability.
What is 500mb height and why does it matter?
500mb height maps show atmospheric pressure around 18,000 feet — a critical layer for tracking storm tracks, ridging, and jet stream placement. Watching 500mb patterns helps forecast Mammoth’s incoming storms and long-range trends.
What are the PNA and PDO, and how do they affect Mammoth weather?
The PNA (Pacific-North American Pattern) influences western U.S. ridging and troughing. A negative PNA favors cold, stormy setups. The PDO (Pacific Decadal Oscillation) affects sea surface temperatures in the North Pacific — a negative PDO often aligns with enhanced storm delivery into California during winter.
👉 Want more answers? Check out the full Mammoth Weather FAQ – 50 Expert Answers to learn more about storms, snow, winds, and long-range patterns from a trusted local source.
Author Bio: Steve Taylor, The Mammoth Snowman. Over the last 40+ years, Steve has spent countless hours studying and learning about Mammoth Mountain Weather and Snow Conditions.
Dr. George, Don Marcelin, Howard Sheckter, and Ted Schlaepfer were his weather mentors at that time. Steve used to hang out with Howard in the Weather War room in the early ’90s, getting first-hand knowledge of Mammoth Weather from the (The Dweeb) himself.
Steve has spent countless hours reading, studying, and watching weather discussions from the NWS and multiple Private Weather Forecasters. He is a long-time member of WeatherBell, Weather West, and AccuWeather Pro. Disclaimer: Steve is a hobbyist forecaster with over 35 years of experience reporting recreational weather and travel reports for the Mammoth Lakes area.