May weather forecastGreencastle, PA

May

Weather in May

May, the last month of the spring in Greencastle, is a pleasant month, with an average temperature fluctuating between 71.2°F (21.8°C) and 51.6°F (10.9°C).

Temperature

The commencement of May sees a shift in the average high-temperature, moving from an enjoyable 61.3°F (16.3°C) in April to a pleasant 71.2°F (21.8°C). Greencastle experiences an average temperature drop to a fresh 51.6°F (10.9°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 3.15" (80mm) of precipitation.

Snowfall

In Greencastle, snow does not fall in May through September.

Daylight

In May, the average length of the day is 14h and 23min.
On the first day of May, sunrise is at 6:10 am and sunset at 8:05 pm. On the last day of the month, sunrise is at 5:44 am and sunset at 8:32 pm EDT.

Sunshine

In Greencastle, the average sunshine in May is 8.6h.

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 hazard from unsafe exposure to UV radiation for the ordinary person.
Note: In May, the average maximum UV index of 6 translates into the following recommendations:
Follow precautions and abide by sun safety rules. Deterrence of sunburn is imperative. Stay out of direct sunlight between 10 a.m. and 4 p.m., when UV radiation is most intense, and remember that not all shade structures provide complete protection. Employ a wide-brim hat for potent defense against up to 50% of UV rays.
Updated: Aug 30, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

The average high-temperature and low-temperature in Greencastle during May are 71.2°F (21.8°C) and 51.6°F (10.9°C) respectively.

February, May, October and December, with an average relative humidity of 79%, are most humid months.

In Greencastle, the average relative humidity in May is 79%.

May is the month with the most rainfall. Rain falls for 18.8 days and accumulates 3.15" (80mm) of precipitation.

In May, the rain falls for 18.8 days. Throughout May, 3.15" (80mm) of precipitation is accumulated.

May through September are months without snowfall.

In May, it doesn't snow. April is the latest month when it typically snows.

In Greencastle, the average day length in May is 14h and 23min.

In May, on the first day of the month, sunrise is at 6:10 am and sunset at 8:05 pm. On the last day of the month, sunrise is at 5:44 am and sunset at 8:32 pm EDT.

The average sunshine duration in May is 8.6h.

May through July, with an average maximum UV index of 6, are months with the highest UV index.

In Greencastle, the average daily maximum UV index in May is 6. A UV Index reading of 6 to 7 represents a high health vulnerability from unprotected exposure to UV radiation.
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 May
Greencastle, PA

  • Average high temperature in May: 71.2°F

The warmest month (with the highest average high temperature) is July (84.4°F).
The month with the lowest average high temperature is January (35.4°F).

  • Average low temperature in May: 51.6°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 (22.5°F).

Average pressure in May
Greencastle, 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
Greencastle, PA

  • Average wind speed in May: 5.8mph

The windiest month (with the highest average wind speed) is January (7.7mph).
The calmest months (with the lowest average wind speed) are July and August (4.5mph).

Average humidity in May
Greencastle, 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
Greencastle, PA

  • Average rainfall in May: 3.15"

The wettest month (with the highest rainfall) is May (3.15").
The driest month (with the least rainfall) is January (1.85").

Average rainfall days in May
Greencastle, 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 days).

Average snowfall in May
Greencastle, PA

  • Average snowfall in May: 0"

The month with the highest snowfall is January (4.53").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in May
Greencastle, PA

  • Average snowfall days in May: 0 days

The month with the highest number of snowfall days is January (8.1 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
Greencastle, 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 36min

The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).

Average sunshine days in May
Greencastle, PA

  • Average sunshine days in May: 10.4 days

The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is May (10.4 days).

Average UV index in May
Greencastle, 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, November and December (UV index 2).

Average cloud cover in May
Greencastle, PA

  • Average cloud cover in May: 46

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 32).

Average visibility in May
Greencastle, PA

  • Average visibility in May: 5mi

The months with the highest visibility are April, June, July, August and November (6mi).
The months with the lowest visibility are January, February, March, May, September, October and December (5mi).