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 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
Palo Alto's September weather features a light decline in high-temperatures, reducing from a warm 79°F (26.1°C) in August to an agreeable 73°F (22.8°C). The average low-temperature, in September, is a fresh 53.6°F (12°C).Humidity
In September, the average relative humidity is 80%.Rainfall
September is the month with the least rainfall. Rain falls for 12.7 days and accumulates 2.09" (53mm) of precipitation.Snowfall
In Palo Alto, snow does not fall in June through September.Daylight
In Palo Alto, the average length of the day in September is 12h and 27min.On the first day of September in Palo Alto, sunrise is at 6:32 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:00 am and sunset at 6:47 pm EDT.
Sunshine
The average sunshine in September is 8.8h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: A daily high UV index of 4 in September leads to these guidelines:
Take heed. Individuals of lighter complexion can be burned in less than half an hour. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September?
What is the driest month?
How many days does it rain in September?
When it does not snow?
Does it snow in September?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Palo Alto have in September?
How high is the UV index in September?
Average temperature in September
Palo Alto, PA
- Average high temperature in September: 73°F
The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (32.5°F).
- Average low temperature in September: 53.6°F
The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (20.5°F).
Average pressure in September
Palo Alto, PA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Palo Alto, PA
- Average wind speed in September: 5.5mph
The windiest month (with the highest average wind speed) is March (8.4mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in September
Palo Alto, PA
- Average humidity in September: 80%
The month with the highest relative humidity is February (83%).
The month with the lowest relative humidity is April (77%).
Average rainfall in September
Palo Alto, PA
- Average rainfall in September: 2.09"
The wettest month (with the highest rainfall) is May (3.39").
The driest month (with the least rainfall) is September (2.09").
Average rainfall days in September
Palo Alto, PA
- Average rainfall days in September: 12.7 days
The month with the highest number of rainy days is May (18.7 days).
The months with the least rainy days are January and November (10.8 days).
Average snowfall in September
Palo Alto, PA
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.47").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Palo Alto, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Palo Alto, PA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The months with the least sunshine are January, February and December (Average sunshine: 4h and 24min).
Average sunshine days in September
Palo Alto, PA
- Average sunshine days in September: 14.9 days
The month with the most sunshine days is November (16.3 days).
The month with the least sunshine days is May (9.6 days).
Average UV index in September
Palo Alto, PA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Palo Alto, PA
- Average cloud cover in September: 38
The months with the most cloud cover are February and December (Cloud cover 53).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in September
Palo Alto, PA
- Average visibility in September: 5mi
The month with the highest visibility is April (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October, November and December (5mi).
Palo Alto, Pennsylvania, USA
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