September weather forecast
Hopland, CA

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Hopland, California, with an average temperature varying between 51.4°F (10.8°C) and 80.8°F (27.1°C).

Temperature

Hopland's average high-temperature in September is a still warm 80.8°F (27.1°C), marking an insignificant difference from the 84.7°F (29.3°C) of August. A stark contrast in day to night temperatures can be seen in September, with an average low-temperature of 51.4°F (10.8°C).

Heat index

September's heat index is appraised at 82.4°F (28°C). Remaining active during long-lasting exposure could cause fatigue, leading to heat cramps.
It is noted that heat index values are ascertained for locations in the shade and with gentle breezes. The heat index could see an increase by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. Factors such as metabolic variation, pregnancy, and physical activity play a role in one's impression of weather. Direct sun exposure is noteworthy in its ability to escalate the felt temperature, potentially adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are essentially critical for children. Kids frequently fail to realize the necessity for resting and hydrating. Thirst is an advanced indication of dehydration - hence, maintaining hydration, especially during extended physical activities, becomes essential.

Humidity

The months with the lowest humidity are July and September, with an average relative humidity of 58%.

Rainfall

In Hopland, during September, the rain falls for 2.5 days and regularly aggregates up to 0.2" (5mm) of precipitation. In Hopland, during the entire year, the rain falls for 83.3 days and collects up to 17.72" (450mm) of precipitation.

Snowfall

In Hopland, snow does not fall in January, March through December.

Daylight

In Hopland, the average length of the day in September is 12h and 25min.
On the first day of September, sunrise is at 6:42 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 6:56 pm PDT.

Sunshine

The average sunshine in September is 10.9h.

UV index

The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: The maximum UV index of 4 during September leads to these instructions:
Make use of precautions - It is urged to ward off sun damage. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat.

Frequently asked questions

What is the average September temperature?

In September, the average high-temperature and low-temperature are 80.8°F (27.1°C) and 51.4°F (10.8°C) respectively. The average heat index (a.k.a. 'real feel', 'feels like'), which combines relative humidity and air temperature, in September is appraised at 82.4°F (28°C).

What is the least humid month?

The months with the lowest humidity are July and September, with an average relative humidity of 58%.

What is the average humidity in September?

In Hopland, the average relative humidity in September is 58%.

How much does it rain in September?

In Hopland, in September, during 2.5 rainfall days, 0.2" (5mm) of precipitation is typically accumulated.

When it does not snow in Hopland?

January, March through December are months without snowfall.

How many hours of daylight does Hopland have in September?

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

When are sunrise and sunset in September in Hopland?

On the first day of September, sunrise is at 6:42 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 6:56 pm PDT.

How long on average sun shines in September?

The average sunshine duration in September is 10.9h.

How high is the UV index in September?

The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health risk from exposure to Sun's UV rays.
Average max. wind speed
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Hopland, CA

Average temperature in September - Hopland, CA
  • Average high temperature in September: 80.8°F

The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is December (53.6°F).

  • Average low temperature in September: 51.4°F

The month with the highest average low temperature is July (53.6°F).
The coldest month (with the lowest average low temperature) is December (37.4°F).

Average pressure in September
Hopland, CA

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

The month with the highest atmospheric pressure is January (30.13"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).

Average wind speed in September
Hopland, CA

Average wind speed in September - Hopland, CA
  • Average wind speed in September: 4.4mph

The windiest months (with the highest average wind speed) are April, May and June (5.5mph).
The calmest month (with the lowest average wind speed) is November (4.2mph).

Average humidity in September
Hopland, CA

Average humidity in September - Hopland, CA
  • Average humidity in September: 58%

The month with the highest relative humidity is March (79%).
The months with the lowest relative humidity are July and September (58%).

Average rainfall in September
Hopland, CA

Average rainfall in September - Hopland, CA
  • Average rainfall in September: 0.2"

The wettest months (with the highest rainfall) are February and December (3.11").
The driest months (with the least rainfall) are July and August (0.08").

Average rainfall days in September
Hopland, CA

Average rainfall days in September - Hopland, CA
  • Average rainfall days in September: 2.5 days

The month with the highest number of rainy days is March (14.3 days).
The month with the least rainy days is August (1.3 days).

Average snowfall in September
Hopland, CA

Average snowfall in September - Hopland, CA
  • Average snowfall in September: 0"

The month with the highest snowfall is February (0.04").
The months with the least snowfall are January, March, April, May, June, July, August, September, October, November and December (0").

Average snowfall days in September
Hopland, CA

Average snowfall days in September - Hopland, CA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (0.3 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).

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

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

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in September: 10h and 5min

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 18min).

Average sunshine days in September
Hopland, CA

Average sunshine days in September - Hopland, CA
  • Average sunshine days in September: 26.9 days

The month with the most sunshine days is July (28.5 days).
The month with the least sunshine days is March (15.9 days).

Average UV index in September
Hopland, CA

Average UV index in September - Hopland, CA
  • Average UV index in September: 4

The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are February and November (UV index 2).

Average cloud cover in September
Hopland, CA

Average cloud cover in September - Hopland, CA
  • Average cloud cover in September: 11

The month with the most cloud cover is March (Cloud cover 45).
The month with the least cloud cover is August (Cloud cover 6).

Average visibility in September
Hopland, CA

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

The months with the highest visibility are February, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January, March and December (5mi).

Hopland, California, USA

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