Climate and monthly weather forecastMercersburg, PA
Climate and monthly weather forecast
Weather in January
January, the same as December, is another cold winter month in Mercersburg, Pennsylvania, with an average temperature varying between 22.1°F (-5.5°C) and 35.2°F (1.8°C). In Mercersburg, the lowest average temperatures are observed in January, with a high of 35.2°F (1.8°C) and a low of 22.1°F (-5.5°C). Weather in January »Weather in February
February, the last month of the winter in Mercersburg, is also a wintry month, with an average temperature ranging between min 24.3°F (-4.3°C) and max 39.7°F (4.3°C). Mercersburg commences February with an average high-temperature of a still icy 39.7°F (4.3°C), maintaining a close resemblance to the previous month. Weather in February »Weather in March
March, the first month of the spring in Mercersburg, is a frosty month, with temperature in the range of an average high of 48.6°F (9.2°C) and an average low of 31.8°F (-0.1°C). In Mercersburg, stepping into March brings a gentle temperature nudge, moving slightly up from February's cold 39.7°F (4.3°C) to a chilly 48.6°F (9.2°C). Weather in March »Weather in April
April in Mercersburg, Pennsylvania, is a comfortable spring month, with an average temperature fluctuating between 41.5°F (5.3°C) and 61.2°F (16.2°C). Noticing a change, the average high-temperature during April moves from March's frosty 48.6°F (9.2°C) to a comfortable 61.2°F (16.2°C). Weather in April »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). 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). Weather in May »Weather in June
June, the first month of the summer in Mercersburg, is a moderately hot month, with an average temperature ranging between max 79.5°F (26.4°C) and min 57.9°F (14.4°C). Mercersburg's transition into June is marked by a minor temperature shift, moving from an agreeable 71.2°F (21.8°C) in May to a moderately hot 79.5°F (26.4°C). Weather in June »Weather in July
July, like June, in Mercersburg, Pennsylvania, is another warm summer month, with an average temperature fluctuating between 84.7°F (29.3°C) and 62.6°F (17°C). With an average high-temperature of 84.7°F (29.3°C) and an average low-temperature of 62.6°F (17°C), July is the warmest month. July's mean heat index is estimated at a hot 93.2°F (34°C). Weather in July »Weather in August
August, the last month of the summer in Mercersburg, is also a moderately hot month, with temperature in the range of an average low of 61.3°F (16.3°C) and an average high of 82°F (27.8°C). With August's arrival, Mercersburg notes an average high-temperature of a still moderately hot 82°F (27.8°C), closely following the trend of the preceding month. Weather in August »Weather in September
The first month of the autumn, September, is still a warm month in Mercersburg, Pennsylvania, with an average temperature fluctuating between 55.4°F (13°C) and 75°F (23.9°C). The average high-temperature shows a slight dip in September, from August's 82°F (27.8°C) to a still moderately hot 75°F (23.9°C). Weather in September »Weather in October
October, like September, in Mercersburg, Pennsylvania, is another enjoyable autumn month, with an average temperature ranging between max 63.3°F (17.4°C) and min 45.5°F (7.5°C). A decrease in the average high-temperature is observed during October, shifting from a moderately hot 75°F (23.9°C) in September to a comfortable 63.3°F (17.4°C). Weather in October »Weather in November
The last month of the autumn, November, is also a fresh month in Mercersburg, Pennsylvania, with an average temperature fluctuating between 50.4°F (10.2°C) and 34.5°F (1.4°C). In Mercersburg, the average high-temperature in November decreases from a comfortable 63.3°F (17.4°C) in October to a cool 50.4°F (10.2°C). Weather in November »Weather in December
December, the first month of the winter in Mercersburg, is also an icy month, with an average temperature ranging between max 40.8°F (4.9°C) and min 28.9°F (-1.7°C). The commencement of December involves a temperature shift, with the average high-temperature dropping from a fresh 50.4°F (10.2°C) in November to a wintry 40.8°F (4.9°C). Weather in December »Updated: Jul 28, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
In Mercersburg, January records the average lowest temperatures, peaking at 35.2°F (1.8°C) and reaching a low of 22.1°F (-5.5°C).
In Mercersburg, during the entire year, the rain falls for 170.5 days and collects up to 31.02" (788mm) of precipitation.
January through April, October through December are months with snowfall.
January is the month with the most snowfall. Snow falls for 9.9 days and accumulates 5.2" (132mm) of snow.
Throughout the year, there are 33.6 snowfall days, and 17.91" (455mm) of snow is accumulated.
With an average of 4.6h of sunshine, January has the least sunshine of the year in Mercersburg.
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index.
February, May, October and December, with an average relative humidity of 79%, are most humid months in Mercersburg.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from EST to EDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from EDT to EST.
April and July, with an average relative humidity of 75%, are the least humid months.
May is the month with the most rainfall. Rain falls for 18.8 days and accumulates 3.19" (81mm) of precipitation.
In Mercersburg, snow does not fall in May through September.
May through July, with an average maximum UV index of 6, are months with the highest UV index.
The month with the longest days is June, with an average of 14h and 54min of daylight.
Mercersburg's warmest month, July, registers temperatures that range from a high of 84.7°F (29.3°C) to a low of 62.6°F (17°C).
With an average of 10.5h of sunshine, July has the most sunshine of the year.
September is the month with the least rainfall. Rain falls for 14 days and accumulates 2.05" (52mm) of precipitation.
The month with the shortest days is December, with an average of 9h and 24min of daylight.
Average temperature
Mercersburg, PA
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).
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
Mercersburg, PA
- Average pressure in January:
30.11"Hg - Average pressure in February:
30.07"Hg - Average pressure in March:
30.08"Hg - Average pressure in April:
29.98"Hg - Average pressure in May:
30.01"Hg - Average pressure in June:
29.95"Hg
- Average pressure in July:
29.98"Hg - Average pressure in August:
30"Hg - Average pressure in September:
30.06"Hg - Average pressure in October:
30.04"Hg - Average pressure in November:
30.14"Hg - Average pressure in December:
30.11"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
Mercersburg, PA
- Average wind speed in January:
7.5mph - Average wind speed in February:
7.4mph - Average wind speed in March:
7.3mph - Average wind speed in April:
7.3mph - Average wind speed in May:
5.7mph - Average wind speed in June:
5.3mph
- Average wind speed in July:
4.4mph - Average wind speed in August:
4.3mph - Average wind speed in September:
4.8mph - Average wind speed in October:
6mph - Average wind speed in November:
6.4mph - Average wind speed in December:
6.8mph
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
Mercersburg, PA
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
Mercersburg, PA
- Average rainfall in January:
2.2" - Average rainfall in February:
2.2" - Average rainfall in March:
2.32" - Average rainfall in April:
2.99" - Average rainfall in May:
3.19" - Average rainfall in June:
2.6"
- Average rainfall in July:
3.03" - Average rainfall in August:
2.83" - Average rainfall in September:
2.05" - Average rainfall in October:
2.87" - Average rainfall in November:
2.2" - Average rainfall in December:
2.52"
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
Mercersburg, PA
- Average rainfall days in January:
10.3 days - Average rainfall days in February:
10.8 days - Average rainfall days in March:
14.3 days - Average rainfall days in April:
16.7 days - Average rainfall days in May:
18.8 days - Average rainfall days in June:
16.5 days
- Average rainfall days in July:
17.8 days - Average rainfall days in August:
16.8 days - Average rainfall days in September:
14 days - Average rainfall days in October:
13.5 days - Average rainfall days in November:
9.9 days - Average rainfall days in December:
11.1 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
Mercersburg, PA
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
Mercersburg, PA
- Average snowfall days in January:
9.9 days - Average snowfall days in February:
9.1 days - Average snowfall days in March:
5.8 days - Average snowfall days in April:
1.3 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0.2 days - Average snowfall days in November:
1.4 days - Average snowfall days in December:
5.9 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 / Average sunshine
Mercersburg, PA
- Average daylight in January:
9h and 42min - Average daylight in February:
10h and 42min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 18min - Average daylight in May:
14h and 24min - Average daylight in June:
14h and 54min
- Average daylight in July:
14h and 42min - Average daylight in August:
13h and 42min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 6min - Average daylight in November:
10h and 0min - Average daylight in December:
9h 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 January:
4h and 36min - Average sunshine in February:
4h and 42min - Average sunshine in March:
6h and 24min - Average sunshine in April:
8h and 24min - Average sunshine in May:
8h and 42min - Average sunshine in June:
10h and 0min
- Average sunshine in July:
10h and 30min - Average sunshine in August:
10h and 12min - Average sunshine in September:
8h and 36min - Average sunshine in October:
5h and 30min - Average sunshine in November:
5h and 36min - Average sunshine in December:
4h 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
Mercersburg, PA
- Average sunshine days in January:
14.4 days - Average sunshine days in February:
12.3 days - Average sunshine days in March:
12.4 days - Average sunshine days in April:
11 days - Average sunshine days in May:
10.3 days - Average sunshine days in June:
11.3 days
- Average sunshine days in July:
11.5 days - Average sunshine days in August:
11.9 days - Average sunshine days in September:
14.2 days - Average sunshine days in October:
15.4 days - Average sunshine days in November:
18 days - Average sunshine days in December:
15.1 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
Mercersburg, PA
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
Mercersburg, PA
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
Mercersburg, PA
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).
