May weather forecastMercersburg, PA
May
Weather in May
May, the last month of the spring in Mercersburg, is an agreeable month, with an average temperature varying between 51.4°F (10.8°C) and 71.2°F (21.8°C).Temperature
The arrival of May brings a change in Mercersburg's weather, with average high-temperatures moving from April's enjoyable 61.2°F (16.2°C) to a pleasant 71.2°F (21.8°C). Mercersburg records a consistent low-temperature of 51.4°F (10.8°C) during May nights.Humidity
The months with the highest humidity are February, May, October and December, with an average relative humidity of 79%.Rainfall
May is the month with the most rainfall. Rain falls for 18.8 days and accumulates 3.19" (81mm) of precipitation.Snowfall
In Mercersburg, snow does not fall in May through September.Daylight
In Mercersburg, Pennsylvania, the average length of the day in May is 14h and 23min.On the first day of May, sunrise is at 6:10 am and sunset at 8:06 pm. On the last day of the month, sunrise is at 5:45 am and sunset at 8:33 pm EDT.
Sunshine
In Mercersburg, the average sunshine in May is 8.7h.UV index
The months with the highest UV index are May through July, with an average maximum UV index of 6. A UV Index of 6 to 7 symbolizes a high health risk from unprotected exposure to Sun's UV rays for the average person.Note: A maximum high UV index of 6 in May translates into the following recommendations:
Dodge overexposure. Fair-skinned people can get singed in less than 20 minutes. Avoid direct exposure to the Sun between 10 a.m. and 4 p.m., the peak period for UV radiation, noting that objects like parasols or canopies might not offer complete sun protection. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Mercersburg, PA
- Average high temperature in May: 71.2°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is January (35.2°F).
- Average low temperature in May: 51.4°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (22.1°F).
Average pressure in May
Mercersburg, PA
- Average pressure in May: 30.01"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in May
Mercersburg, PA
- Average wind speed in May: 5.7mph
The windiest month (with the highest average wind speed) is January (7.5mph).
The calmest month (with the lowest average wind speed) is August (4.3mph).
Average humidity in May
Mercersburg, PA
- Average humidity in May: 79%
The months with the highest relative humidity are February, May, October and December (79%).
The months with the lowest relative humidity are April and July (75%).
Average rainfall in May
Mercersburg, PA
- Average rainfall in May: 3.19"
The wettest month (with the highest rainfall) is May (3.19").
The driest month (with the least rainfall) is September (2.05").
Average rainfall days in May
Mercersburg, PA
- Average rainfall days in May: 18.8 days
The month with the highest number of rainy days is May (18.8 days).
The month with the least rainy days is November (9.9 days).
Average snowfall in May
Mercersburg, PA
- Average snowfall in May: 0"
The month with the highest snowfall is January (5.2").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in May
Mercersburg, PA
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is January (9.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in May /
Average sunshine in May
Mercersburg, PA
- Average daylight in May: 14h and 24min
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 May: 8h and 42min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 36min).
Average sunshine days in May
Mercersburg, PA
- Average sunshine days in May: 10.3 days
The month with the most sunshine days is November (18 days).
The month with the least sunshine days is May (10.3 days).
Average UV index in May
Mercersburg, PA
- Average UV index in May: 6
The months with the highest UV index are May, June and 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 May
Mercersburg, PA
- Average cloud cover in May: 45
The months with the most cloud cover are January, February and December (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in May
Mercersburg, PA
- Average visibility in May: 5mi
The months with the highest visibility are April, June, July and November (6mi).
The months with the lowest visibility are January, February, March, May, August, September, October and December (5mi).
