Mammoth Lakes
California, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Mammoth Lakes, CA

The ever-scenic and perfect water reflections in the clear water of trees, rocks, and distant mountains in Mammoth Lakes, California
The ever-scenic and perfect water reflections in the clear water of trees, rocks, and distant mountains in Mammoth Lakes, California
The first month of the autumn, September, is also an agreeable month in Mammoth Lakes, California, with average temperature ranging between min 37.6°F (3.1°C) and max 69.4°F (20.8°C).

Temperature

In September, the average high-temperature slightly decreases, from a moderately hot 76.8°F (24.9°C) in August, to an agreeable 69.4°F (20.8°C). In Mammoth Lakes, California, the average low-temperature is 37.6°F (3.1°C).

Rainfall

In Mammoth Lakes, it is raining for 2 days, with typically 0.4" (9.4mm) of accumulated precipitation. In Mammoth Lakes, during the entire year, the rain falls for 63 days and collects up to 23" (583.3mm) of precipitation.

Snowfall

In Mammoth Lakes, it doesn't snow. In October, it regularly snows. Throughout the year, 206.1" (5235mm) of snow is accumulated.

Daylight

In September, the average length of the day in Mammoth Lakes is 12.4h.

Sunshine

In September, the average sunshine is 10h.

UV index

The average daily maximum UV index in September is 8. A UV Index reading of 8 to 10 represents a very high health risk from the exposure to the Sun's UV rays for average individuals.
In September, the average maximum UV index of 8 translate into the following recommendations:
Take extra precautions. Protection against sun damage is required. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.

What is the temperature in September in Mammoth Lakes?

The average high-temperature, in September, is 69.4°F (20.8°C), while the average low-temperature is 37.6°F (3.1°C).

How many days does it rain in September in Mammoth Lakes?

In Mammoth Lakes, California, during September, the rain falls for 2 days and regularly aggregates up to 0.4" (9.4mm) of precipitation.

Does it snow in Mammoth Lakes in September?

In Mammoth Lakes, California, in September, it doesn't snow. In October, it regularly snows.

How many hours of daylight does Mammoth Lakes have in September?

In Mammoth Lakes, California, the average length of the day in September is 12.4h.

How many hours of sunshine does Mammoth Lakes have in September?

In September, the average sunshine in Mammoth Lakes, California, is 10h.

What is the UV index reading in September in Mammoth Lakes?

In September, the average daily maximum UV index in Mammoth Lakes, California, is 8. A UV Index estimate of 8 to 10 represents a very high health threat from unsafe exposure to the Sun's UV rays.
Average temperature in September - Mammoth Lakes, CA
  • Average high temperature in September: 69.5°F

The warmest month (with the highest average high temperature) is July (77.7°F).
The month with the lowest average high temperature is January (40.1°F).

  • Average low temperature in September: 37.5°F

The month with the highest average low temperature is July (45.3°F).
The coldest month (with the lowest average low temperature) is January (14.8°F).

Average rainfall in September - Mammoth Lakes, CA
  • Average rainfall in September: 0.4"

The wettest month (with the highest rainfall) is January (4.6").
The driest month (with the lowest rainfall) is August (0.3").

Average rainfall days in September - Mammoth Lakes, CA
  • Average rainfall days in September: 2 days

Months with the highest number of rainy days are January and February (9 days).
Months with the lowest number of rainy days are August and September (2 days).

Average snowfall in September - Mammoth Lakes, CA
  • Average snowfall in September: 0"

The month with the highest snowfall is December (45.3").
Months with the lowest snowfall are July, August and September (0").

Average daylight in September / Average sunshine in September - Mammoth Lakes, CA
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.7h).
The month with shortest days is December (Average daylight: 9.6h).

  • Average sunshine in September: 10h

The month with most sunshine is July (Average sunshine: 12h).
The month with least sunshine is December (Average sunshine: 6h).

Average UV index in September - Mammoth Lakes, CA
  • Average UV index in September: 8

Months with the highest UV index are June and July (UV index 11).
The month with the lowest UV index is December (UV index 2).