Väder i Mammoth Lakes (Mammoth Mountain) i september
Mammoth Lakes i september: skönt, torrt, med ren luft — inte den bästa tiden att besöka.
Uppdaterad september 2026 · klimatnormaler från ERA5-reanalysen
Plats 9 av 12 månader i Mammoth Lakes · plats 1388 av 1413 resmål att besöka i september · komfort 19/100 (nivå F)
- Dagar
- 22°C
- Nätter
- 3°C
- Regndagar
- 4
- Sol
- 11.4 h
- Luftfuktighet
- 47%
- Dagsljus
- 12 h

Resenärernas anteckningar om Mammoth Lakes i september
Mammoth Lakes-forum threads on a late-September visit describe afternoon highs as typically running around the mid-seventies Fahrenheit, posters calling nights considerably chillier, dropping into the mid-forties. Regulars call this genuinely one of the better stretches for hiking, biking, boating and even a last swim, the lakes about as warm as they get all year by this point. Posters recommend Hot Creek, the Earthquake Fault and the Twin Lakes waterfall as easy local drives, June Lake Loop, Mono Lake and Bodie all reasonable if venturing further. Regulars call heading into the high country, Rock Creek to the south or Tuolumne Meadows to the north, a real chance at early fall color. Posters describe local events like an art festival over Labor Day weekend as worth timing a visit around. Regulars recommend real layers for the evening chill despite the pleasant daytime warmth. The record: 22.3C days feeling like 20C, 3.2C nights, 12.5mm across nearly 4 days and 47 percent humidity.
Andra månader i Mammoth Lakes
Mammoth Lakes-forum threads on an October visit describe peak fall color as genuinely running mid-September through early October, posters warning color at higher elevations has typically passed by the twentieth. Regulars call June Lake Loop, Lundy Canyon and Rock Creek Canyon real standard viewing spots, several posters naming the Tom's Place turnoff as the way into Rock Creek's aspens. Posters call Convict Lake's aspen grove a real highlight, several regulars naming its roughly three-mile loop as an easy way to see color without a long hike. Regulars call timing genuinely shifting year to year with weather, several threads recommending checking weekly updates at the Welcome Center before planning around peak color. Posters recommend lower-elevation spots once higher color has passed, several regulars calling this standard given how the show moves downhill as October progresses. The record: 17.3C days, -1.5C nights, 21.3mm across nearly 3 days and 48 percent humidity.
Mammoth Lakes-forum threads on April skiing are consistently enthusiastic, posters calling this among the strongest months of the season thanks to a deep base built from heavy earlier-season storms. Regulars describe spring snow here as genuinely excellent once it softens, smooth corduroy in the morning turning forgiving rather than icy by afternoon. Posters call the mountain noticeably less crowded than winter break, some describing it as nearly empty by mid-to-late April. Regulars are direct year-to-year variability is real, some Aprils bringing fresh storms and a foot or two of new snow, others closer to a bare, sunny stretch. Posters recommend checking current conditions before committing to a specific week. Regulars call the full mountain typically open through the third weekend of April most years. The record: 10.9C days feeling like 9C, -3.2C nights, a notably high 21.6cm of fresh accumulation and 68 percent humidity.
Mammoth Lakes-forum threads comparing seasons call July genuine peak summer, wildflowers out at the high elevations and conditions noticeably milder for hiking than the intense heat of late August. Posters name Devils Postpile, Rainbow Falls and Red's Meadow as standout July destinations, along with the Mono Lake and June Lake Loop area just north for swimming, hiking and horseback riding. Convict Lake, a short drive south, is repeatedly recommended as an easy add-on for anyone with a spare afternoon. Regulars call the days noticeably longer and the evenings still comfortable compared to how quickly things cool once late August arrives. Layers for a genuinely large day-to-night swing at this elevation are standing advice regardless of how warm the afternoon runs. The record: 26.8C days feeling like 25C, 7.3C nights, a low 42 percent humidity and 14.5 hours of daylight.
Mammoth Lakes-forum threads on January conditions confirm this and February are historically the snowiest months, though posters are candid the mountain can be genuinely finicky year to year about when and how much actually falls. When a storm cycle hits, conditions can turn severe fast - high winds and blizzard conditions that drop the mountain down to running just one or two lifts, and posters recommend real first-layer thermal gear rather than assuming standard ski clothing will be enough. The main highway in and out is an all-weather route, but chain control during storms is standard and can add real time to any drive. Regulars call a base layer and a flexible schedule the two most important things to bring, since a powder day can arrive with very little warning either way. The record: 5C days feeling like 1C, -9.4C nights, an extraordinarily high 103.7cm of fresh snowfall and 67 percent humidity.
Lägg till din egen anteckning från Mammoth Lakess kort på kartan.
Klimatnormaler för Mammoth Lakes — september
Månadsmedelvärden från ERA5-reanalysen. AQI är månadens medelvärde för det amerikanska luftkvalitetsindexet.
Trängsel i Mammoth Lakes i september
Hur mycket folk det är på själva platsen — skollov och storhelger, månaderna en redaktör har märkt upp, och hur eftertraktade vädret gör dem. Aldrig en del av komfortpoängen.
Mest folkAspen colour, Summer break i United States(uppskattat)
Mest folkMycket folkMellansäsongLugnt
Bästa månaderna för vädret i Mammoth Lakes
Rankat efter resmålets egen klimatkomfortpoäng över året — något helt annat än hur trångt det blir (se Trängsel ovan).
Hyfsat väderVädret i Mammoth Lakes toppar januari–mars, bäst kring februari.
Bäst väderHyfsat väderTuffast väder
På gång i Mammoth Lakes i september
Återkommande säsongsevenemang, naturskådespel, stängningar och helger — utvalda och källhänvisade.
- Öppning
Tioga Pass road season
20 maj – 5 nov · vanligtvisLedsäsongStängningarHighway 120 over Tioga Pass is the short way into Yosemite, and it is shut by snow for half the year. Ploughing starts around 15 April and takes one to two months, so the opening date is never announced far ahead. Källa ↗
- Öppning
Reds Meadow road opens
10 jun – 15 okt · vanligtvisSommarsäsongen öppnarThe narrow road down to Devils Postpile and Rainbow Falls opens once the snow clears — typically June, but in a heavy-snow or reconstruction year it can slip into July — and a mandatory shuttle runs while it does. Before that the valley is a long walk from Minaret Vista. Källa ↗
- Natur
Aspen colour
15 sep – 20 okt · vanligtvisHöstfärgerTrångtAspen stands in the June Lake Loop and the Lakes Basin turn from mid-September, working down from the high canyons through October. Weekend parking at the popular pull-outs goes early. Källa ↗
I närheten, och något är på gång
Inom 300 km från Mammoth Lakes — en dagstur eller ett kort hopp — med något på gång den här månaden. Aldrig en del av komfortpoängen.
Var ligger Mammoth Lakes?
Mammoth Lakes i september — vanliga frågor
- Är september en bra tid att besöka Mammoth Lakes?
- Mammoth Lakes i september: skönt, torrt, med ren luft — inte den bästa tiden att besöka. Månaden ligger på plats 9 av 12 för Mammoth Lakes enligt SeasonMaps komfortpoäng (19/100).
- Hur är vädret i Mammoth Lakes i september?
- I september har Mammoth Lakes i snitt 22.3 °C som dagshögsta och 3.2 °C som nattlägsta, med ungefär 12.5 mm regn fördelat på cirka 3.7 regndagar.
- Hur är luftkvaliteten i Mammoth Lakes i september?
- Mammoth Lakes har ett genomsnittligt amerikanskt luftkvalitetsindex (AQI) på ungefär 42 i september.
Inom 300 km: Yosemite National Parks Tioga and Glacier Point roads open, runt 10 maj – 10 nov och Sequoia National Parks Crystal Cave tours, runt 20 maj – 10 sep.