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 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
Winnetka observes an average high-temperature of a still moderately hot 83.1°F (28.4°C) in September, barely different from 85.6°F (29.8°C) in August. In September, the average low-temperature in Winnetka, California, records at an enjoyable 63°F (17.2°C) during the nights.Heat index
The heat index value for September is estimated at 84.2°F (29°C). If one persists in activity during exposure, it could induce weariness and subsequently, heat cramps.Take note of the fact that heat index values are based on shaded circumstances with light airflows. The presence of direct sunlight can raise the heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'felt air temperature', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. The effect of weather is individual, with a variety of people experiencing it differently due to distinctions in body mass, height, and level of activity. One's exposure to direct sunlight has the potential to intensify the heat sensation, increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Kids are generally in more danger than adults because they perspire less. Their large skin surface area compared to their small bodies and the excessive heat due to their actions raises their risk.
Humidity
The average relative humidity in September is 52%.Rainfall
In Winnetka, California, in September, it is raining for 2.6 days, with typically 0.16" (4mm) of accumulated precipitation. Throughout the year, in Winnetka, there are 42.7 rainfall days, and 6.46" (164mm) of precipitation is accumulated.Snowfall
In Winnetka, snow does not fall in January through November.Daylight
In Winnetka, California, the average length of the day in September is 12h and 22min.On the first day of the month, sunrise is at 6:28 am and sunset at 7:19 pm. On the last day of September, sunrise is at 6:48 am and sunset at 6:39 pm PDT.
Sunshine
In September, the average sunshine in Winnetka is 10.8h.UV index
The months with the highest UV index in Winnetka are June through September, with an average maximum UV index of 6. A UV Index estimate of 6 to 7 represents a high health risk from unsafe exposure to UV radiation for average individuals.Note: The maximum UV index of 6 during September translates into these guidelines:
Use measures and accept sun safety conventions. Guarding against skin and eye trauma is of high priority. Avoid direct Sun exposure and seek shade between 10 a.m. and 4 p.m., when UV radiation is at its peak, but keep in mind that not all shade structures provide complete protection. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Frequently asked questions
How hot is September in Winnetka?
What is the average humidity in September in Winnetka?
How many days does it rain in September in Winnetka?
When it does not snow in Winnetka?
What is the average length of the day in September in Winnetka?
When is the sunrise / sunset in September in Winnetka?
How long on average sun shines in September in Winnetka?
When is the highest UV index in Winnetka?
What is the UV index intensity in September in Winnetka?
Average temperature in September
Winnetka, CA
- Average high temperature in September: 83.1°F
The warmest month (with the highest average high temperature) is August (85.6°F).
The month with the lowest average high temperature is December (61.9°F).
- Average low temperature in September: 63°F
The month with the highest average low temperature is August (64.8°F).
The coldest month (with the lowest average low temperature) is December (46.9°F).
Average pressure in September
Winnetka, CA
- Average pressure in September: 29.9"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in September
Winnetka, CA
- Average wind speed in September: 4.5mph
The windiest months (with the highest average wind speed) are January and December (6.1mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).
Average humidity in September
Winnetka, CA
- Average humidity in September: 52%
The month with the highest relative humidity is June (59%).
The month with the lowest relative humidity is November (47%).
Average rainfall in September
Winnetka, CA
- Average rainfall in September: 0.16"
The wettest month (with the highest rainfall) is February (1.22").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Winnetka, CA
- Average rainfall days in September: 2.6 days
The month with the highest number of rainy days is March (6.5 days).
The month with the least rainy days is June (1.4 days).
Average snowfall days in September
Winnetka, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (0.1 days).
The months with the least snowfall days are January, February, March, April, May, June, July, August, September, October and November (0 days).
Average daylight in September /
Average sunshine in September
Winnetka, 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 5min
The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The months with the least sunshine are January, February and December (Average sunshine: 6h and 48min).
Average sunshine days in September
Winnetka, CA
- Average sunshine days in September: 25.5 days
The months with the most sunshine days are August and October (27.3 days).
The month with the least sunshine days is February (22 days).
Average UV index in September
Winnetka, CA
- Average UV index in September: 6
The months with the highest UV index are June, July, August and September (UV index 6).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in September
Winnetka, CA
- Average cloud cover in September: 7
The month with the most cloud cover is March (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 4).
Average visibility in September
Winnetka, 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).
Winnetka, California, USA
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