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
September's climate shows a minor adjustment in average high-temperatures to a still warm 83.3°F (28.5°C) from August's 85.1°F (29.5°C). Nightly readings in September display a noticeable downturn from daily highs, with the average low-temperature registering a cool 54.1°F (12.3°C).Heat index
For most parts of September, the heat index is computed to be a tropical 86°F (30°C). One might feel worn out with persistent exposure and activity, resulting in heat cramps.Always consider that heat index estimations are for light winds and places in the shade. Direct sunlight might lead to a heat index increase by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', determines the feeling of heat when you account for the relative humidity. This impact is subjective, influenced by the person's physical activity and individual heat perception, affected by factors including wind, attire, and metabolic differences. Direct sun rays can make one feel hotter, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. Young individuals usually face greater risks than adults as their sweat production is less. Also, their larger skin surface relative to their small bodies and the high heat generation due to their activity contributes to their vulnerability.
Humidity
With an average relative humidity of 57%, September is the least humid month.Rainfall
January through May, September through December are months with rainfall in Gilroy. September is the first month it rains in Gilroy, California. Throughout September, in the average 1.7 rainfall days, it receives 0.04" (1mm) of precipitation. In Gilroy, during the entire year, the rain falls for 43.4 days and collects up to 3.66" (93mm) of precipitation.Daylight
In September, the average length of the day in Gilroy is 12h and 24min.On the first day of September, sunrise is at 6:37 am and sunset at 7:34 pm. On the last day of the month, sunrise is at 7:01 am and sunset at 6:50 pm PDT.
Sunshine
In Gilroy, the average sunshine in September is 11.3h.UV index
The average daily maximum UV index in September in Gilroy is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: In September, the maximum UV index of 5 translates into these guidelines:
Take necessary precautions - Defending against sun damage is advocated. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
Frequently asked questions
Is it hot in Gilroy during September?
What is the least humid month in Gilroy?
What is the average humidity in September in Gilroy?
When does it start raining in Gilroy?
What is the average length of the day in September in Gilroy?
When are sunrise and sunset in September in Gilroy?
How long on average sun shines in September in Gilroy?
What is the UV index intensity in September in Gilroy?
Average temperature in September
Gilroy, CA
- Average high temperature in September: 83.3°F
The warmest month (with the highest average high temperature) is August (85.1°F).
The month with the lowest average high temperature is December (57.6°F).
- Average low temperature in September: 54.1°F
The months with the highest average low temperature are August and September (54.1°F).
The coldest months (with the lowest average low temperature) are February and March (40.6°F).
Average pressure in September
Gilroy, CA
- Average pressure in September: 29.92"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.92"Hg).
Average wind speed in September
Gilroy, CA
- Average wind speed in September: 4.2mph
The windiest month (with the highest average wind speed) is May (5.3mph).
The calmest month (with the lowest average wind speed) is November (3.9mph).
Average humidity in September
Gilroy, CA
- Average humidity in September: 57%
The month with the highest relative humidity is March (74%).
The month with the lowest relative humidity is September (57%).
Average rainfall in September
Gilroy, CA
- Average rainfall in September: 0.04"
The wettest month (with the highest rainfall) is December (0.83").
The driest months (with the least rainfall) are June, July and August (0").
Average rainfall days in September
Gilroy, CA
- Average rainfall days in September: 1.7 days
The month with the highest number of rainy days is March (8.3 days).
The month with the least rainy days is August (0.6 days).
Average daylight in September /
Average sunshine in September
Gilroy, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in September: 11h and 2min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 0min).
Average sunshine days in September
Gilroy, CA
- Average sunshine days in September: 27.7 days
The month with the most sunshine days is July (29.9 days).
The month with the least sunshine days is March (21.4 days).
Average UV index in September
Gilroy, CA
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 3).
Average cloud cover in September
Gilroy, CA
- Average cloud cover in September: 9
The month with the most cloud cover is March (Cloud cover 35).
The month with the least cloud cover is July (Cloud cover 7).
Average visibility in September
Gilroy, 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).
Gilroy, California, USA
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