September weather forecastPalo Alto, PA

September

Weather in September

The first month of the autumn, September, is also an agreeable month in Palo Alto, Pennsylvania, with an average temperature varying between 53.6°F (12°C) and 73°F (22.8°C).

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.

Frequently asked questions

In Palo Alto, in September, the average high-temperature is 73°F (22.8°C), and the average low-temperature is 53.6°F (12°C). In July, the average heat index (a.k.a. 'real feel', 'apparent temperature'), which combines air temperature and relative humidity, is estimated at 87.8°F (31°C).

In September, the average relative humidity in Palo Alto is 80%.

The month with the least rainfall is September, when the rain falls for 12.7 days and typically collects 2.09" (53mm) of precipitation.

In Palo Alto, in September, during 12.7 rainfall days, 2.09" (53mm) of precipitation is typically accumulated.

June through September are months without snowfall.

In Palo Alto, in September, it doesn't snow. In October, it regularly snows.

The average day length in September is 12h and 27min.

On the first day of September, 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.

In Palo Alto, the average sunshine duration in September is 8.8h.

In Palo Alto, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health risk from exposure to Sun's UV rays.
Average high temperature
Average low temperature
Average pressure
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
Average rainfall days
Average snowfall
Average snowfall days
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

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 30min

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 48min

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).