Mammoth Mountain & Eastern Sierra Weather Forecast

Mammoth Mountain & Eastern Sierra Weather Forecast

Footloose Sports Bike Shop - 760-934-2400
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Mammoth Lakes and Eastern Sierra Weather for Monday, August 23rd, 2021 @ 10:53 AM

Good morning, we have thick haze and dissipated smoke with us this morning.

Air Quality levels are in the stage 1 range right now. Expect air quality to improve once the PM winds come into the lower elevations. Only to decrease again during the late-night and early morning hours.

Here is the link you can use to monitor the air quality in the Eastern Sierra. When the pointer is in the green or yellow range you’re good to go out and play. When it hits orange and red I would avoid being outside for extended periods of time.

Synopsis… Close to average highs with dry conditions will continue into mid-week and then we will see a warming trend with highs peaking on Friday and Saturday.

Temperatures: Highs will be in the mid-60s on Mammoth Mountain and up in the Mammoth Lakes Basin at the 9000-foot level.

Mammoth Lakes will be in the mid-70s with Bishop into the upper 80s to low 90s. Expect highs to come up about 3-6 degrees by Friday into Saturday.

Night-time lows have cooled now into the mid-40s for the high country and into the mid-50s for Bishop and Round Valleys.

Winds: Expect afternoon winds in the 10-15 MPH range in the lower elevations with upper elevations seeing gusts in the 20-35+ MPH range at times.

Here are the links to the local NWS Forecasts for Main Lodge & the Mammoth Lakes Basin, Mammoth Lakes, June Lake, Crowley Lake, and Bishop.

Extended Outlook: Next week a trough of low pressure will lower heights in the area and highs will drop down to average to below average for the week.

Looking out towards the early Fall season we can expect to start to see insider sliders show up by mid to late September into early October. Many a year there will also be the first dusting of snow later in the month of September.

It’s any ones guess what to expect during October into November. Over the last 20 years or so it seems that time period is more dry than wet anymore. Hopefully, we can get an early-season AR into the area during early to mid-November to lay some base down.

For the upcoming winter, most of the extended models have us in a neutral ENSO state, with several showing a weak La Nina. As of now, I expect the chances of an average snowfall winter are much greater than the 3rd year of exponential drought.

I posted the latest outlook from the ECMWF for October – December down the page a bit. 

Images Updated Monday – Wednesday & Friday by 1 PM

Current Update Monday, August 23th @ 12:38 PM

HRRR Temperature Forecast

HRRR Precipitation Forecast

HRRR Current Dew Point

HRRR Current Humidity Levels

Precipitable Water

ECMWF Accumulated Precipitation


ECMWF EPS Ensemble going out 10 days / 240 hour

Temperature Anomaly EPS

Long Range Outlooks from the ECMWF

Mammoth Mountain and Eastern Sierra Weather Posts

Who Are We?

Steve Taylor – Mammoth Snowman Over the last 30+ years, Snowman has spent countless hours studying and learning about Mammoth Mountain Weather and Snow Conditions first hand. He has been skiing around the hill with marked ski poles since March of 1991 so he can measure the fresh snowfall amounts out on the hill. 

Snowman started blogging this information back in 1990 on the old Mammoth BBS system, then the RSN Forums and then on to in 2004 with Video & Photo Blog report. (No YouTube back then). Facebook got added to the fold back in 2008 and then the Facebook Group in 2016. 

Reports, videos, and photos from the website have been featured on both local TV Stations here in Mammoth, along with AP, Fox, ABC, CBS, and NBC News.

Ted Schlaepfer – Mammoth WeatherGuy – The Powder Forecast – Posted Tuesday and Fridays at 5 PM November into Mid May. These forecasts are now responsible for many people getting multiple powder days on Mammoth Mountain over the years.  

Ted’s Bio: Ted has been a full-time Meteorologist (CCM) for the past 25+ years. He has always been fascinated with the weather,” skiing was just a natural extension of my love for snow and rain. I started skiing at age 5,  first discovered Mammoth in 1979 as a youth, and have been a regular visitor since the late ’80s.”.

Here is the link to The WeatherGuys Powder Forecast Page. 

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