September weather forecast
Martinez, CA

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A cow grazing in the vast Martinez Hills
A cow grazing in the vast Martinez Hills' fields near Martinez Town, California

Weather in September

September, the first month of the autumn in Martinez, is still a warm month, with an average temperature varying between 57.6°F (14.2°C) and 82.8°F (28.2°C).

Temperature

September reports an average high-temperature of a still moderately hot 82.8°F (28.2°C), slightly varied from August's 83.8°F (28.8°C). Martinez registers a significant drop in temperature in September, with average nighttime lows of 57.6°F (14.2°C).

Heat index

The heat index for September is estimated at 84.2°F (29°C). Enduring exposure and ongoing activity could cause a sense of fatigue and subsequent heat cramps.
Metrics for the heat index primarily focus on shaded spots and light wind conditions. If directly exposed to the sun, the heat index could rise by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', combines both the air temperature and the humidity level to give a perceived human temperature. Elements such as metabolic variations, pregnancy, and physical exertion can influence one's weather perception. Under direct sun rays, the felt temperature might be heightened, with the heat index increasing by 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it's vital to remain hydrated, particularly during prolonged physical activities.

Humidity

September and October, with an average relative humidity of 56%, are the least humid months.

Rainfall

In Martinez, California, during September, the rain falls for 2 days and regularly aggregates up to 0.08" (2mm) of precipitation. Throughout the year, in Martinez, there are 48.9 rainfall days, and 4.96" (126mm) of precipitation is accumulated.

Daylight

In Martinez, the average length of the day in September is 12h and 25min.
On the first day of September in Martinez, sunrise is at 6:39 am and sunset at 7:37 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:52 pm PDT.

Sunshine

In September, the average sunshine in Martinez is 11.1h.

UV index

In September, the average daily maximum UV index in Martinez is 5. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the average person.
Note: In September, the maximum UV index of 5 transforms into these recommendations:
Make use of precautions - Suggestions to resist sunburn are communicated. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Enhance your sun protection with tightly woven, yet airy clothing.
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Frequently asked questions

Is it hot in Martinez during September?

The average high-temperature and low-temperature in Martinez during September are 82.8°F (28.2°C) and 57.6°F (14.2°C) respectively. The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which combines air temperature and relative humidity, in September is estimated at 84.2°F (29°C).

What are the least humid months in Martinez?

The months with the lowest humidity in Martinez are September and October, with an average relative humidity of 56%.

What is the average humidity in September in Martinez?

In Martinez, California, the average relative humidity in September is 56%.

How much does it rain in Martinez in September?

In Martinez, in September, it is raining for 2 days, with typically 0.08" (2mm) of accumulated precipitation.

What is the average length of the day in September in Martinez?

In Martinez, the average day length in September is 12h and 25min.

What time are sunrise and sunset in September in Martinez?

In September, on the first day of the month, sunrise is at 6:39 am and sunset at 7:37 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:52 pm PDT.

How many hours of sunshine does Martinez have in September?

In September, the average sunshine duration in Martinez, California, is 11.1h.

How high is the UV index in September in Martinez?

In Martinez, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate health threat from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Martinez, CA

Average temperature in September - Martinez, CA
  • Average high temperature in September: 82.8°F

The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is December (55.4°F).

  • Average low temperature in September: 57.6°F

The month with the highest average low temperature is September (57.6°F).
The coldest months (with the lowest average low temperature) are January and December (42.3°F).

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Average pressure in September
Martinez, CA

Average pressure in September - Martinez, CA
  • Average pressure in September: 29.92"Hg

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

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Average wind speed in September
Martinez, CA

Average wind speed in September - Martinez, CA
  • Average wind speed in September: 5.8mph

The windiest month (with the highest average wind speed) is May (7.4mph).
The calmest month (with the lowest average wind speed) is November (4.5mph).

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Average humidity in September
Martinez, CA

Average humidity in September - Martinez, CA
  • Average humidity in September: 56%

The month with the highest relative humidity is March (74%).
The months with the lowest relative humidity are September and October (56%).

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Average rainfall in September
Martinez, CA

Average rainfall in September - Martinez, CA
  • Average rainfall in September: 0.08"

The wettest month (with the highest rainfall) is February (0.98").
The driest months (with the least rainfall) are July and August (0.04").

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Average rainfall days in September
Martinez, CA

Average rainfall days in September - Martinez, CA
  • Average rainfall days in September: 2 days

The month with the highest number of rainy days is March (8.3 days).
The month with the least rainy days is August (1 days).

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Average daylight in September /
Average sunshine in September
Martinez, CA

Average daylight in September / Average sunshine in September - Martinez, CA
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).

  • Average sunshine in September: 11h and 1min

The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).

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Average sunshine days in September
Martinez, CA

Average sunshine days in September - Martinez, CA
  • Average sunshine days in September: 27.6 days

The month with the most sunshine days is July (29 days).
The months with the least sunshine days are February and March (22.1 days).

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Average UV index in September
Martinez, CA

Average UV index in September - Martinez, CA
  • Average UV index in September: 5

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).

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Average cloud cover in September
Martinez, CA

Average cloud cover in September - Martinez, CA
  • Average cloud cover in September: 10

The months with the most cloud cover are March and December (Cloud cover 36).
The month with the least cloud cover is July (Cloud cover 7).

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Average visibility in September
Martinez, CA

Average visibility in September - Martinez, CA
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

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Martinez, California, USA

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