September weather forecast
Monterey, CA

englishespañol中文
Share
The rugged mountainous coast of Big Sur in Monterey, California
The rugged mountainous coast of Big Sur in Monterey, California

Weather in September

Shifting into September, Monterey is graced with the year's highest temperature, peaking at 72.5°F (22.5°C). Meanwhile, rainfall maintains its consistency from August, with only 0.12" (3mm). However, daylight hours begin to shrink noticeably to 12.4 hours, signifying the onset of Fall. The wind, similarly, softens, averaging out at 5.7mph (9.2km/h). Therefore, September is significant for being the hottest month in Monterey yet signals the changing of the seasons with its dwindling daylight and gentler winds.

Temperature

Monterey's warmest month, September, registers temperatures that range from a high of 72.5°F (22.5°C) to a low of 55.2°F (12.9°C).

Humidity

The average relative humidity in September in Monterey, California, is 72%.

Rainfall

In Monterey, in September, during 2.4 rainfall days, 0.12" (3mm) of precipitation is typically accumulated. Throughout the year, in Monterey, there are 73.6 rainfall days, and 11.77" (299mm) of precipitation is accumulated.

Ocean temperature

The months with the warmest seawater in Monterey, California, are August and September, with an average ocean temperature of 58.1°F (14.5°C).
Note: Dipping into 58.1°F (14.5°C) below 50°F (10°C) is possible with the right protection; absent that, anticipate cold shock and hampered breathing. Swimming momentarily at 55.4°F (13°C) can be jarring.

Daylight

In Monterey, the average length of the day in September is 12h and 24min.
On the first day of September in Monterey, sunrise is at 6:39 am and sunset at 7:35 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:51 pm PDT.

Sunshine

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

UV index

June through September, with an average maximum UV index of 5, are months with the highest UV index in Monterey. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the average person.
Note: The average daily UV index of 5 in September transforms into the following instructions:
Take precautions - Protection against sun damage is advised. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.
[Resources]

Frequently asked questions

What time of the year is the hottest in Monterey?

The highest temperatures in Monterey, California, are recorded in September, with averages reaching a high of 72.5°F (22.5°C) and a low of 55.2°F (12.9°C).

What are the temperatures in Monterey in September?

The high-temperature, in September, in Monterey, is 72.5°F (22.5°C), while the low-temperature averages to 55.2°F (12.9°C).

What is the average humidity in September in Monterey?

The average relative humidity in September in Monterey, California, is 72%.

How much does it rain in Monterey in September?

In Monterey, California, in September, during 2.4 rainfall days, 0.12" (3mm) of precipitation is typically accumulated.

When is the ocean warmest in Monterey?

The months with the warmest seawater in Monterey, California, are August and September, with an average ocean temperature of 58.1°F (14.5°C).

How cold is the water in September in Monterey?

In September, the average ocean temperature in Monterey is 58.1°F (14.5°C). Swimming in 58.1°F (14.5°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

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

In September, the average day length in Monterey, California, is 12h and 24min.

What time are sunrise and sunset in September in Monterey?

On the first day of September in Monterey, sunrise is at 6:39 am and sunset at 7:35 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:51 pm PDT.

How long on average sun shines in September in Monterey?

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

What is the month with the highest UV index in Monterey?

June through September, with an average maximum UV index of 5, are months with the highest UV index.

What is the UV index reading in September in Monterey?

In Monterey, California, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate vulnerability 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
Monterey, CA

Average temperature in September - Monterey, CA
  • Average high temperature in September: 72.5°F

The warmest month (with the highest average high temperature) is September (72.5°F).
The month with the lowest average high temperature is December (57.2°F).

  • Average low temperature in September: 55.2°F

The months with the highest average low temperature are August and September (55.2°F).
The coldest month (with the lowest average low temperature) is February (46°F).

[Resources]

Average pressure in September
Monterey, CA

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

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is September (29.92"Hg).

[Resources]

Average wind speed in September
Monterey, CA

Average wind speed in September - Monterey, CA
  • Average wind speed in September: 5.7mph

The windiest months (with the highest average wind speed) are April and May (7.5mph).
The calmest month (with the lowest average wind speed) is August (5.6mph).

[Resources]

Average humidity in September
Monterey, CA

Average humidity in September - Monterey, CA
  • Average humidity in September: 72%

The months with the highest relative humidity are March and May (76%).
The month with the lowest relative humidity is November (68%).

[Resources]

Average rainfall in September
Monterey, CA

Average rainfall in September - Monterey, CA
  • Average rainfall in September: 0.12"

The wettest month (with the highest rainfall) is December (2.4").
The driest months (with the least rainfall) are July and August (0.08").

[Resources]

Average rainfall days in September
Monterey, CA

Average rainfall days in September - Monterey, CA
  • Average rainfall days in September: 2.4 days

The month with the highest number of rainy days is March (12.5 days).
The month with the least rainy days is August (1.1 days).

[Resources]

Average sea temperature in September
Monterey, CA

Average sea temperature in September - Monterey, CA
  • Average sea temperature in September: 58.1°F

The best months for swimming (with the highest average sea temperature) are August and September (58.1°F).
The coldest month (with the lowest average sea temperature) is April (53.8°F).

[Resources]

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

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

The month with the longest days is June (Average daylight: 14h and 36min).
The month with the shortest days is December (Average daylight: 9h and 42min).

  • 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: 6h and 0min).

[Resources]

Average sunshine days in September
Monterey, CA

Average sunshine days in September - Monterey, CA
  • Average sunshine days in September: 25.9 days

The month with the most sunshine days is July (27.3 days).
The month with the least sunshine days is March (16.8 days).

[Resources]

Average UV index in September
Monterey, CA

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

The months with the highest UV index are June, July, August and September (UV index 5).
The month with the lowest UV index is December (UV index 3).

[Resources]

Average cloud cover in September
Monterey, CA

Average cloud cover in September - Monterey, CA
  • Average cloud cover in September: 12

The month with the most cloud cover is March (Cloud cover 34).
The month with the least cloud cover is July (Cloud cover 9).

[Resources]

Average visibility in September
Monterey, CA

Average visibility in September - Monterey, 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).

[Resources]

Monterey, California, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location