Contents
- Weather in May
- Frequently asked questions
- Average temperature in May
- Average pressure in May
- Average wind speed in May
- Average humidity in May
- Average rainfall in May
- Average rainfall days in May
- Average snowfall in May
- Average snowfall days in May
- Average daylight in May
- Average sunshine in May
- Average sunshine days in May
- Average UV index in May
- Average cloud cover in May
- Average visibility in May
Weather in May
Temperature
With the onset of May, Norristown experiences a temperature shift, with the average high-temperature moving from a refreshing 60.8°F (16°C) in April to a pleasant 71.4°F (21.9°C). In Norristown, May nights cool down to an average of 53.4°F (11.9°C).Humidity
In May, the average relative humidity is 76%.Rainfall
In May, in Norristown, the rain falls for 16 days. Throughout May, 1.77" (45mm) of precipitation is accumulated. In Norristown, during the entire year, the rain falls for 138.2 days and collects up to 15.59" (396mm) of precipitation.Snowfall
January through March, May and December are months with snowfall. May is the first month it typically snows in Norristown. Throughout May, in the average 0.1 snowfall days, it receives 0.16" (4mm) of snow. Throughout the year, there are 15.8 snowfall days, and 2.13" (54mm) of snow is accumulated.Daylight
The average length of the day in May in Norristown is 14h and 25min.On the first day of the month, sunrise is at 6:00 am and sunset at 7:56 pm. On the last day of May, sunrise is at 5:34 am and sunset at 8:24 pm EDT.
Sunshine
In Norristown, the average sunshine in May is 8.5h.UV index
The months with the highest UV index are May through August, with an average maximum UV index of 6. A UV Index estimate of 6 to 7 represents a high threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: A maximum daily UV index of 6 during May morphs into the following directions:
Avoid overexposure. Fair-skinned individuals can burn in under 20 minutes. Attempt to stay under shade and limit exposure to the Sun between 10 a.m. and 4 p.m., when UV radiation is at its peak. Remember, devices such as parasols or canopies might not provide complete sun protection. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Alert! The snow's reflection can amplify the UV radiation of the Sun nearly twice.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Norristown in May?
What is the average humidity in May?
How much does it rain in May?
When does it start to snow?
What is the average length of the day in May?
What time are sunrise and sunset in May?
How many hours of sunshine does Norristown have in May?
What is the month with the highest UV index?
How high is the UV index in May?
Average temperature in May
Norristown, PA
- Average high temperature in May: 71.4°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (36.7°F).
- Average low temperature in May: 53.4°F
The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in May
Norristown, PA
- Average pressure in May: 30.01"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 May
Norristown, PA
- Average wind speed in May: 6.6mph
The windiest month (with the highest average wind speed) is March (8.3mph).
The calmest months (with the lowest average wind speed) are July and August (5.3mph).
Average humidity in May
Norristown, PA
- Average humidity in May: 76%
The months with the highest relative humidity are February and October (79%).
The months with the lowest relative humidity are April and July (72%).
Average rainfall in May
Norristown, PA
- Average rainfall in May: 1.77"
The wettest month (with the highest rainfall) is July (1.89").
The driest month (with the least rainfall) is February (0.91").
Average rainfall days in May
Norristown, PA
- Average rainfall days in May: 16 days
The month with the highest number of rainy days is May (16 days).
The month with the least rainy days is November (7.4 days).
Average snowfall in May
Norristown, PA
- Average snowfall in May: 0.16"
The months with the highest snowfall are February and March (0.55").
The months with the least snowfall are April, June, July, August, September, October and November (0").
Average snowfall days in May
Norristown, PA
- Average snowfall days in May: 0.1 days
The month with the highest number of snowfall days is January (5.2 days).
The months with the least snowfall days are April, June, July, August, September and October (0 days).
Average daylight in May /
Average sunshine in May
Norristown, PA
- Average daylight in May: 14h and 2min
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 May: 8h and 3min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days in May
Norristown, PA
- Average sunshine days in May: 12.8 days
The month with the most sunshine days is November (20.5 days).
The months with the least sunshine days are May and June (12.8 days).
Average UV index in May
Norristown, PA
- Average UV index in May: 6
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, March, November and December (UV index 2).
Average cloud cover in May
Norristown, PA
- Average cloud cover in May: 47
The month with the most cloud cover is February (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in May
Norristown, PA
- Average visibility in May: 5mi
The months with the highest visibility are January, February, March, April, June, July, August, October, November and December (6mi).
The months with the lowest visibility are May and September (5mi).
Norristown, Pennsylvania, USA
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