Mammoth Mountain Weather & Discussion
Almost Daily Weather for Mammoth Mountain and the Southern Eastern Sierra
Saturday, August 1st, 2026 @ 5 PM – Mostly clear skies with very warm Summer days continue in the Eastern Sierra on this gorgeous Saturday evening.
Currently at the Main Lodge, the temp is 76 degrees; at the Summit of Mammoth Mountain, you will find a cool 67 degrees with a WSW wind at 16 mph gusting to 28 mph.
In Mammoth Lakes, the temp is 83 with light winds; down in Bishop, the temp is 103 in town and 106 at the Airport, also with light winds at this time.
Weather Summary: A strong ridge of high pressure will continue to bring warm temps to the high country and hot conditions in the lower elevations. The ridge does weaken a bit on Monday and then slowly rebuilds to very strong by the end of next week.
Over the next 6 -10 days, expect a daily repeat with the warm temps and less-than-cool nights. There could be a return to isolated buildups by next weekend. No signs of a juicy return to a Summer monsoon cycle yet.
Confidence Level is high that we will see ridging in the area through the next 10 days.
3-5 Day Forecast:
Main Lodge / Mammoth Lakes Basin: Clear Skies Sunday into Tuesday with upper 70s to the lower 80s. Overnight lows in the upper 50s. SW Winds 5-10 mph with gusts to 20 mph.
Mammoth Lakes: Clear Skies Sunday into Tuesday with mid 80s. Overnight lows in the upper 50s to lower 60s. SW Winds 5-10 mph with gusts to 20 mph.
Bishop: Clear Skies Sunday into Tuesday with temps in the low to mid 100s. Lows before sunrise in the mid to upper 60s.
Fantasy Forecast Period 10-14 Day Outlook: By August 10th, we start the trend toward cooling and the death of the SW ridge.
The ridge will weaken and set up towards the 4 corners area. That pattern would bring temps in the 70s back to Mammoth Mountain with upper 70s in Mammoth Lakes, and mid-90s down in Bishop. Overnight lows will also recover much better for better sleeping weather.
I would expect some isolated buildups during this time frame, but no major monsoon pattern is showing up just yet. That can change quickly during August, especially when the high is near the 4 Corners area.
Weather Data: The gif below shows the weather trend out the next 16 days. Near the end of the run, you can see the ridge that is creating the hot days in California will be gone.
Fantasy Forecast Period Outlook Weeks 3 & 4: Looking way out into mid-August, I continue to see much lower heights in the area compared to where we are today.
Temps do look to remain a bit above average with more isolated T-storms in the forecast.
Confidence in the details this time frame will always be low, but the overall trend of lower heights looks good as of today.
El Niño continues to build and is forecast to enter into record territory on all the forecast models. This one is easterly based and is already in super El Niño territory with Niño 3.4 already at 2.3 degrees above average. That is ahead of the very productive 97-98 super El Niño that pounded California.
How all this affects our upcoming winter is what’s in question. Besides the El Niño, there are a multitude of other factors that will come into play that will determine next winter’s snowfall.
If I were to make my call for the upcoming winter based on the data I have now, the call would be well above average precipitation expected, with high snow levels, lots of base snow, with some rain mixed in at times.
❓ 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.