Mammoth Mountain Weather Forecast and Long Range Outlook

9-8-2022 @ 7:50 AM – Good morning today’s window cast shows clear skies over Mammoth Mountain and over all areas of the Eastern Sierra.

On Wednesday the heat continued and there were also some build-ups in the area with some light rain from Mammoth Mountain down to Bishop. I did see a couple of large rain columns off in the distance during the evening hours.

For today expect a 20%-30% chance of T Storms in the area again with some thunder, lighting, and light rain possible.
By Saturday the chance of rain is up to 50% and then 60% on Sunday.

All this is being caused by a change in the pattern that is pulling in the remnants of hurricane Kay into Southern California and then the eastern Sierra. Over the next few days expect temperatures to come down 10-15 degrees. 

For those of you heading outside for an Adventure, Resort level highs at 8900 feet at Main Lodge and up in the Mammoth Lakes basin will be in the mid-70s today and then into the mid-60s over the weekend with lows dropping into the 40s at night.

Winds will be light at 5-15 MPH except in areas where T Storms develop, outflow winds could gust in the 20-30+ MPH range. Due beware that any storms that develop especially by the weekend will be very wet.

Be prepared, get out early for your adventures and go inside or take cover when thunder roars.

Here are the links to the specific highs, lows, and wind speeds for many of the major recreation points in the Eastern Sierra: Mammoth Mountain Main Lodge, Top of Mammoth Mountain, Mammoth Lakes, June Lake, Crowley Lake, Toms Place, Rock Creek Lake, Bishop & Mill Pond, South Lake. 

Please Note: Fire Restrictions are in place on all National Forest Service and BLM Lands in the Eastern Sierra.

Current Satellite View

Mammoth Mountain Weather View

Mammoth Mountain 10 Day Weather Outlook and Discussion

9-8-2022 @ 11:15 AM There is some interesting weather developing for Mammoth Mountain and the Eastern Sierra over the next several days.

First up the large dome of high pressure that has been bringing all the above-normal temperatures will be moving off to our east as the pattern starts to change.

Hurricane Kay to our south is expected to be reduced to a tropical storm and then dissipate with the remnants being drawn north into Southern California and then possibly into the Eastern Sierra.

With that said weather models struggle with this rare pattern, I have seen us get abundant rain to just a sprinkle to nothing. This time around models has been consistent with the moisture actually making its way to the Eastern Sierra.

Over the next couple of days look for an increased chance of T Storms with the chance for locally heavy rain under any storms that form by Saturday and again on Sunday.

By early next week, storms will become isolated and completely gone by mid-week as a low-pressure system tries to move in from the west. That low will bring average highs with SW winds and dry conditions.


Both the EPS and the GEFS are very close with the pattern over the next 10 days. The EPS is a bit weaker with the low of the coast at day 8 onward.

14-km EPS Global North America 500 hPa Height Anom

The EPS seems a bit weak on the QPF forecasted for the area. The thought is as of now that it will be much wetter then what the model is showing below.


After a 10 day heat wave it’s nice to the the Temperature Anomaly going into the blue range for Mammoth Lakes and down into the Bishop area.

14-km EPS Global United States 2-m Temperature Anom

November into March Mammoth Weather Trends

9-7-22 @ 9:12 AM – A weak La Nina will be gaining some strength into late Fall and then is forecast to start to weaken and then go neutral sometime by late December into early February.

How this all plays out for winter is still up in the air.  The good news from what we are seeing right now is the longest-range models are not a day in and day out dry like we were seeing at this time last year.

An updated run of the EPS Seasonal is now out and posted below. The Mammoth Mountain area on these updates would be in for an average year if what we see below came to fruition.

Again long range data is not a forecast just an outlook, I personally like to look at all the data and see what the trends are. 


ENSO - La Nina & El Nino

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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