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
A mild drop in Princeton's average high-temperature is observed in September, transitioning from a torrid 97°F (36.1°C) in August to a tropical 90.7°F (32.6°C). Princeton's nighttime temperatures in September reflect a stark contrast to the day's highs, falling to an average low of 61°F (16.1°C).Humidity
With an average relative humidity of 36%, September is the least humid month.Rainfall
In September, the rain falls for 1.7 days. Throughout September, 0.08" (2mm) of precipitation is accumulated. In Princeton, during the entire year, the rain falls for 58.9 days and collects up to 6.89" (175mm) of precipitation.Daylight
In Princeton, the average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:37 am and sunset at 7:38 pm. On the last day of September, in Princeton, sunrise is at 7:03 am and sunset at 6:51 pm PDT.
Sunshine
In Princeton, the average sunshine in September is 11.2h.UV index
In Princeton, the average daily maximum UV index in September is 6. A UV Index value of 6 to 7 symbolizes a high threat to health from unprotected exposure to Sun's UV rays for the average person.Note: The maximum daily UV index of 6 in September converts into the following recommendations:
Persist in precautions and follow sun safety policies. Keeping sunburn at bay is imperative. The hours from 10 a.m. to 4 p.m. have the most intense UV radiation. As much as possible, limit direct sun exposure during this period. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear.
Frequently asked questions
How hot does it get in Princeton in September?
What is the least humid month in Princeton?
What is the average humidity in September in Princeton?
How much does it rain in Princeton in September?
What is the average length of the day in September in Princeton?
When is the sunrise / sunset in September in Princeton?
How long on average sun shines in September in Princeton?
What is the UV index intensity in September in Princeton?
Average temperature in September
Princeton, CA
- Average high temperature in September: 90.7°F
The warmest month (with the highest average high temperature) is July (98.8°F).
The month with the lowest average high temperature is December (54.5°F).
- Average low temperature in September: 61°F
The month with the highest average low temperature is July (61.5°F).
The coldest month (with the lowest average low temperature) is December (42.1°F).
Average pressure in September
Princeton, CA
- Average pressure in September: 29.91"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Princeton, CA
- Average wind speed in September: 5.1mph
The windiest month (with the highest average wind speed) is March (6.6mph).
The calmest month (with the lowest average wind speed) is August (5mph).
Average humidity in September
Princeton, CA
- Average humidity in September: 36%
The month with the highest relative humidity is March (71%).
The month with the lowest relative humidity is September (36%).
Average rainfall in September
Princeton, CA
- Average rainfall in September: 0.08"
The wettest months (with the highest rainfall) are February and December (1.3").
The driest months (with the least rainfall) are July and August (0.04").
Average rainfall days in September
Princeton, CA
- Average rainfall days in September: 1.7 days
The month with the highest number of rainy days is March (10.4 days).
The month with the least rainy days is July (1 days).
Average daylight in September /
Average sunshine in September
Princeton, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 11h and 1min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 48min).
Average sunshine days in September
Princeton, CA
- Average sunshine days in September: 28 days
The month with the most sunshine days is July (29.8 days).
The month with the least sunshine days is March (19.7 days).
Average UV index in September
Princeton, CA
- Average UV index in September: 6
The months with the highest UV index are June, July and August (UV index 7).
The months with the lowest UV index are February, November and December (UV index 3).
Average cloud cover in September
Princeton, CA
- Average cloud cover in September: 8
The months with the most cloud cover are March and December (Cloud cover 36).
The month with the least cloud cover is July (Cloud cover 4).
Average visibility in September
Princeton, 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).
Princeton, California, USA
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