Mammoth Mountain & Eastern Sierra Weather Forecast

Mammoth Mountain & Eastern Sierra Weather Forecast

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Mammoth Lakes and Eastern Sierra Weather for Friday, August 13th, 2021 @ 1:28 PM

Weather Synopsis: The weather story will be warm temperatures, isolated thunderstorms and very hazy skies as a ridge of high pressure will dominate our weather into Monday. By the middle of next week, there will be some cooler temperatures on the way for the area.

Temperatures: Highs through Monday will be in the mid-70s on Mammoth Mountain and up in the Mammoth Lakes Basin at the 9000-foot level. Mammoth Lakes will be in the low 80s with Bishop into the low 100s.

Smoke and Haze: AQI levels in the hazy skies are in the 50-80 range with some higher levels at times. For those with lung and heart issues now is not the time to be outside recreating in the Eastern Sierra. 

More than likely the Eastern Sierra is going to see waves of haze and smoke at times until at least mid Fall. It’s going to take the first snow and rains of the upcoming wet season to get rid of all the hazy skies.

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: Expect much cooler highs and lows by the middle of next week. Let’s hope that allows the fires to have less smoke output.

Looking out towards Fall and into the Winter months, it’s looking dry and warm to start. Models have moved from a neutral winter to forecasting a la Nina to set up again.

Kind of early to jump on how strong it could be. Mammoth and the central Sierra have done good with weak La Nina’s, not so bad with moderate ones but if it’s strong again expect a drier year.

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


Updated Friday August13th @ 1 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

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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