January weather forecastPhiladelphia, PA
January
Weather in January
In the heart of winter, Philadelphia, Pennsylvania, experiences cooler temperatures and occasional snowfall. The average high hovers around 37.4°F (3°C) with lows typically reaching 25.5°F (-3.6°C). A precipitation level of 0.83" (21mm) ushers in nearly half of the month under a cloud cover. Residents can expect seven days of rainfall and about four days of snowfall. With just fewer than ten hours of daylight, January holds the shortest days of the year in Philadelphia.Temperature
With its high average temperature of 37.4°F (3°C) and a low of 25.5°F (-3.6°C), January is regarded as the coldest month.Humidity
In January, the average relative humidity is 74%.Rainfall
January and February are months with the least rain when the rain falls for 7.3 days and typically aggregates up to 0.83" (21mm) of rain.Snowfall
Months with snowfall are January through May, November and December. In Philadelphia, Pennsylvania, in January, during 3.8 snowfall days, 0.87" (22mm) of snow is typically accumulated. Throughout the year, there are 11.4 snowfall days, and 2.87" (73mm) of snow is accumulated.Ocean temperature
In Philadelphia, in January, the average water temperature is 41.9°F (5.5°C).Note: Swimming in 41.9°F (5.5°C) can be lethal. Merely spending a few minutes in 55.4°F (13°C) waters feels harsh, and venturing below 50°F (10°C) might disrupt breathing control and bring about cold shock, contingent on individual resilience.
Daylight
The average length of the day in January is 9h and 43min.On the first day of the month, sunrise is at 7:22 am and sunset at 4:45 pm. On the last day of January, sunrise is at 7:10 am and sunset at 5:18 pm EST.
Sunshine
The average sunshine in January is 5h.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a low threat to health from unprotected exposure to Sun's UV rays for the average person.Note: A maximum daily UV index of 2 during January morphs into the following directions:
Apart from children, who require continuous protection, most can endure sun exposure for up to an hour without experiencing burns. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in January
Philadelphia, PA
- Average high temperature in January: 37.4°F
The warmest month (with the highest average high temperature) is July (86.4°F).
The month with the lowest average high temperature is January (37.4°F).
- Average low temperature in January: 25.5°F
The month with the highest average low temperature is July (69.3°F).
The coldest month (with the lowest average low temperature) is January (25.5°F).
Average pressure in January
Philadelphia, PA
- Average pressure in January: 30.08"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in January
Philadelphia, PA
- Average wind speed in January: 8.2mph
The windiest months (with the highest average wind speed) are March and April (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.6mph).
Average humidity in January
Philadelphia, PA
- Average humidity in January: 74%
The month with the highest relative humidity is October (77%).
The months with the lowest relative humidity are April and August (71%).
Average rainfall in January
Philadelphia, PA
- Average rainfall in January: 0.83"
The wettest month (with the highest rainfall) is August (1.65").
The driest months (with the least rainfall) are January and February (0.83").
Average rainfall days in January
Philadelphia, PA
- Average rainfall days in January: 7.3 days
The month with the highest number of rainy days is July (14.8 days).
The month with the least rainy days is February (7.2 days).
Average snowfall in January
Philadelphia, PA
- Average snowfall in January: 0.87"
The month with the highest snowfall is February (0.98").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in January
Philadelphia, PA
- Average snowfall days in January: 3.8 days
The month with the highest number of snowfall days is January (3.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average sea temperature in January
Philadelphia, PA
- Average sea temperature in January: 41.8°F
The best month for swimming (with the highest average sea temperature) is August (75.9°F).
The coldest month (with the lowest average sea temperature) is February (39.9°F).
Average daylight in January /
Average sunshine in January
Philadelphia, PA
- Average daylight in January: 9h and 42min
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 24min).
- Average sunshine in January: 5h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in January
Philadelphia, PA
- Average sunshine days in January: 20.4 days
The month with the most sunshine days is December (20.9 days).
The month with the least sunshine days is May (13.3 days).
Average UV index in January
Philadelphia, PA
- Average UV index in January: 2
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in January
Philadelphia, PA
- Average cloud cover in January: 45
The months with the most cloud cover are February and March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in January
Philadelphia, PA
- Average visibility in January: 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).
