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 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 in Norwalk stands at a still warm 82.2°F (27.9°C), closely aligned with August's 83.1°F (28.4°C). In the month of September, Norwalk experiences an average low-temperature of 64.9°F (18.3°C).Heat index
The heat index value for September is calculated to be 84.2°F (29°C). Persisting in activity during exposure could lead to weariness and subsequently to heat cramps.Regarding the heat index, one should be aware it's determined by shaded settings and mild winds. The direct sunshine could escalate the heat index values by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is an estimation of the warmth sensation when considering humidity levels. Elements such as metabolic variations, pregnancy, and physical exertion can shape one's weather perception. In the direct sunlight, the weather's impact can be amplified, possibly boosting the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly meaningful for babies and toddlers. Kids are usually more vulnerable than adults, given their lesser sweating ability. Along with their larger skin surface relative to their small stature and the excess heat due to their activity, their risk is amplified.
Humidity
In Norwalk, the average relative humidity in September is 58%.Rainfall
In Norwalk, in September, it is raining for 3 days, with typically 0.16" (4mm) of accumulated precipitation. In Norwalk, during the entire year, the rain falls for 49.5 days and collects up to 7.05" (179mm) of precipitation.Daylight
In Norwalk, the average length of the day in September is 12h and 22min.On the first day of September in Norwalk, California, sunrise is at 6:26 am and sunset at 7:17 pm. On the last day of the month, sunrise is at 6:46 am and sunset at 6:37 pm PDT.
Sunshine
In Norwalk, California, the average sunshine in September is 10.6h.UV index
June through September, with an average maximum UV index of 6, are months with the highest UV index in Norwalk. A UV Index estimate of 6 to 7 represents a high health hazard from unprotected exposure to Sun's UV rays for the average person.Note: The maximum UV index, 6 during September, leads to the following recommendations:
Conform to measures and uphold sun safety traditions. Warding off skin and eye harm is necessary. UV radiation from the Sun is most intense between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. Employ a wide-brim hat for potent defense against up to 50% of UV rays.
Frequently asked questions
What is the usual temperature for Norwalk in September?
What is the average humidity in September in Norwalk?
How many days does it rain in September in Norwalk?
What is the average length of the day in September in Norwalk?
What time are sunrise and sunset in September in Norwalk?
How many hours of sunshine does Norwalk have in September?
What are the months with the highest UV index in Norwalk?
What is the UV index reading in September in Norwalk?
Average temperature in September
Norwalk, CA
- Average high temperature in September: 82.2°F
The warmest month (with the highest average high temperature) is August (83.1°F).
The month with the lowest average high temperature is December (64.6°F).
- Average low temperature in September: 64.9°F
The month with the highest average low temperature is August (65.7°F).
The coldest month (with the lowest average low temperature) is February (50.5°F).
Average pressure in September
Norwalk, CA
- Average pressure in September: 29.89"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are June and September (29.89"Hg).
Average wind speed in September
Norwalk, CA
- Average wind speed in September: 4.8mph
The windiest month (with the highest average wind speed) is April (6.1mph).
The calmest month (with the lowest average wind speed) is October (4.7mph).
Average humidity in September
Norwalk, CA
- Average humidity in September: 58%
The month with the highest relative humidity is June (66%).
The month with the lowest relative humidity is November (51%).
Average rainfall in September
Norwalk, CA
- Average rainfall in September: 0.16"
The wettest month (with the highest rainfall) is December (1.46").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Norwalk, CA
- Average rainfall days in September: 3 days
The month with the highest number of rainy days is March (7.1 days).
The month with the least rainy days is June (1.2 days).
Average daylight in September /
Average sunshine in September
Norwalk, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 10h and 4min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).
Average sunshine days in September
Norwalk, CA
- Average sunshine days in September: 23.5 days
The months with the most sunshine days are January and August (25.6 days).
The month with the least sunshine days is February (21.1 days).
Average UV index in September
Norwalk, CA
- Average UV index in September: 6
The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are February, November and December (UV index 4).
Average cloud cover in September
Norwalk, CA
- Average cloud cover in September: 9
The months with the most cloud cover are March and December (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 6).
Average visibility in September
Norwalk, 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).
Norwalk, California, USA
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