Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
With the onset of September, the average high-temperature stands at a still pleasant 70.3°F (21.3°C), closely aligned with August's 71.6°F (22°C). September witnesses an average nighttime temperature of 52.2°F (11.2°C).Humidity
The months with the lowest humidity are September and October, with an average relative humidity of 75%.Rainfall
In September, the rain falls for 4.4 days. Throughout September, 0.55" (14mm) of precipitation is accumulated. In Fortuna, during the entire year, the rain falls for 110.4 days and collects up to 28.07" (713mm) of precipitation.Snowfall
January, March through December are months without snowfall in Fortuna.Daylight
In September, the average length of the day is 12h and 26min.On the first day of September, sunrise is at 6:44 am and sunset at 7:48 pm. On the last day of the month, sunrise is at 7:12 am and sunset at 6:59 pm PDT.
Sunshine
The average sunshine in September is 10.3h.UV index
In September, the average daily maximum UV index in Fortuna is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum UV index, 4 during September, leads to the following recommendations:
Undertake protective steps - Preventing sun damage is advised. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Fortuna in September?
What is the least humid month in Fortuna?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
What is the average length of the day in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Fortuna have in September?
What is the UV index reading in September?
Average temperature in September
Fortuna, CA
- Average high temperature in September: 70.3°F
The warmest month (with the highest average high temperature) is August (71.6°F).
The months with the lowest average high temperature are February and December (53.1°F).
- Average low temperature in September: 52.2°F
The month with the highest average low temperature is August (53.2°F).
The coldest month (with the lowest average low temperature) is February (41.7°F).
Average pressure in September
Fortuna, CA
- Average pressure in September: 29.97"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is August (29.96"Hg).
Average wind speed in September
Fortuna, CA
- Average wind speed in September: 6.4mph
The windiest months (with the highest average wind speed) are March and June (8.3mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity in September
Fortuna, CA
- Average humidity in September: 75%
The months with the highest relative humidity are February and March (82%).
The months with the lowest relative humidity are September and October (75%).
Average rainfall in September
Fortuna, CA
- Average rainfall in September: 0.55"
The wettest month (with the highest rainfall) is December (5.16").
The driest months (with the least rainfall) are July and August (0.12").
Average rainfall days in September
Fortuna, CA
- Average rainfall days in September: 4.4 days
The month with the highest number of rainy days is March (16.8 days).
The month with the least rainy days is August (1.8 days).
Average snowfall in September
Fortuna, CA
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.31").
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
Fortuna, 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 and November (0 days).
Average daylight in September /
Average sunshine in September
Fortuna, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 10h and 2min
The months with the most sunshine are July and August (Average sunshine: 11h and 36min).
The month with the least sunshine is December (Average sunshine: 5h and 6min).
Average sunshine days in September
Fortuna, CA
- Average sunshine days in September: 25.4 days
The month with the most sunshine days is July (28.1 days).
The month with the least sunshine days is March (12.3 days).
Average UV index in September
Fortuna, CA
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, March, November and December (UV index 3).
Average cloud cover in September
Fortuna, CA
- Average cloud cover in September: 18
The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is August (Cloud cover 15).
Average visibility in September
Fortuna, CA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, September, October, November and December (6mi).
The month with the lowest visibility is August (5mi).
Fortuna, California, USA
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