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 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
Transitioning into September, Julian records an average high-temperature of a moderately hot 84.2°F (29°C), almost identical to August's 87.3°F (30.7°C). During September, Julian experiences a consistent low-temperature average of 62.8°F (17.1°C).Heat index
September's average heat index is calculated to be a tropical 86°F (30°C). If one sustains activity during exposure, it could lead to a sense of fatigue, with a chance of heat cramps.Note that heat index values are valued for light wind and location in the shade. 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 'real feel', embodies the combination of air temperature and moisture content to illustrate perceived heat. The individual's impression of temperature can be affected by numerous factors such as metabolic variations, physical exertion, and attire. Direct sun rays can make one feel hotter, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for babies and toddlers. Young children are more at risk than adults since they tend to sweat less. Moreover, their large skin surface in proportion to their small bodies and the high heat production due to their activities contribute to their vulnerability.
Humidity
In Julian, the average relative humidity in September is 53%.Rainfall
In Julian, California, during September, the rain falls for 5.5 days and regularly aggregates up to 0.51" (13mm) of precipitation. Throughout the year, there are 62 rainfall days, and 6.38" (162mm) of precipitation is accumulated.Snowfall
June through October are months without snowfall in Julian.Daylight
The average length of the day in September in Julian is 12h and 22min.On the first day of September in Julian, sunrise is at 6:21 am and sunset at 7:10 pm. On the last day of the month, sunrise is at 6:40 am and sunset at 6:31 pm PDT.
Sunshine
In September, the average sunshine in Julian, California, is 10.4h.UV index
June through September, with an average maximum UV index of 6, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high health vulnerability from unprotected exposure to Sun's UV rays for the average person.Note: In September, the UV index of 6 transforms into the following advice:
Continue precautions and advocate sun safety advice. Deterrence of sunburn is indispensable. Stay in the shade and limit direct sun exposure between 10 a.m. and 4 p.m., when UV radiation is at its strongest. Remember, however, that not all shade structures provide full sun protection. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.
Frequently asked questions
How hot is September in Julian?
What is the average humidity in September in Julian?
How many days does it rain in September in Julian?
When it does not snow in Julian?
What is the average length of the day in September in Julian?
When is the sunrise / sunset in September in Julian?
How long on average sun shines in September in Julian?
When is the highest UV index in Julian?
How high is the UV index in September in Julian?
Average temperature in September
Julian, CA
- Average high temperature in September: 84.2°F
The warmest month (with the highest average high temperature) is August (87.3°F).
The month with the lowest average high temperature is December (61.3°F).
- Average low temperature in September: 62.8°F
The month with the highest average low temperature is August (64.9°F).
The coldest month (with the lowest average low temperature) is February (44.2°F).
Average pressure in September
Julian, CA
- Average pressure in September: 29.86"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Julian, CA
- Average wind speed in September: 4.1mph
The windiest month (with the highest average wind speed) is May (5.7mph).
The calmest month (with the lowest average wind speed) is September (4.1mph).
Average humidity in September
Julian, CA
- Average humidity in September: 53%
The month with the highest relative humidity is May (62%).
The month with the lowest relative humidity is November (51%).
Average rainfall in September
Julian, CA
- Average rainfall in September: 0.51"
The wettest month (with the highest rainfall) is February (0.94").
The driest month (with the least rainfall) is June (0.08").
Average rainfall days in September
Julian, CA
- Average rainfall days in September: 5.5 days
The month with the highest number of rainy days is March (7.6 days).
The month with the least rainy days is June (1.5 days).
Average snowfall in September
Julian, CA
- Average snowfall in September: 0"
The month with the highest snowfall is March (6.7").
The months with the least snowfall are June, July, August, September and October (0").
Average daylight in September /
Average sunshine in September
Julian, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in September: 10h and 2min
The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 6h and 42min).
Average sunshine days in September
Julian, CA
- Average sunshine days in September: 21.8 days
The month with the most sunshine days is June (27.5 days).
The month with the least sunshine days is July (19.4 days).
Average UV index in September
Julian, 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 November and December (UV index 3).
Average cloud cover in September
Julian, CA
- Average cloud cover in September: 8
The months with the most cloud cover are March and December (Cloud cover 23).
The month with the least cloud cover is August (Cloud cover 6).
Average visibility in September
Julian, 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).
Julian, California, USA
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