May weather forecast
Lancaster, PA

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The city of Lancaster, Pennsylvania, in a stunning early morning panorama
The city of Lancaster, Pennsylvania, in a stunning early morning panorama

Weather in May

May marks the official beginning of the warm season in Lancaster, Pennsylvania. Displaying substantial heat compared to the preceding months, temperatures climb to an average high of about 21.3°C (70.3°F). The extended daylight hours and persistent rainfall provide optimal growth conditions for plant life. An increase in relative humidity augments the general sense of warmth. As the temperatures rise steadily, it is an ideal time to engage in various outdoor activities, adorning summer wear.

Temperature

The arrival of May signals an increase in the average high-temperature, moving from a moderate 15.7°C (60.3°F) in April to a pleasant 21.3°C (70.3°F). Nighttime temperatures hover around an average low of 11.4°C (52.5°F) in May.

Humidity

With an average relative humidity of 81%, May is the most humid month.

Rainfall

In Lancaster, in May, during 17.8 rainfall days, 71mm (2.8") of precipitation is typically accumulated. In Lancaster, during the entire year, the rain falls for 153.4 days and collects up to 718mm (28.27") of precipitation.

Snowfall

In Lancaster, snow does not fall in May through October.

Daylight

In Lancaster, the average length of the day in May is 14h and 25min.
On the first day of May, sunrise is at 6:04 am and sunset at 8:00 pm. On the last day of the month, sunrise is at 5:38 am and sunset at 8:27 pm EDT.

Sunshine

In May, the average sunshine in Lancaster is 8.2h.

UV index

The months with the highest UV index are May through July, with an average maximum UV index of 6. A UV Index value of 6 to 7 symbolizes a high threat to health from exposure to the Sun's UV rays for average individuals.
Note: The maximum UV index, 6 during May, leads to the following recommendations:
Implement precautions and maintain sun safety methods. Avoidance of sunburn is demanded. Stay in the shade and limit sun exposure from 10 a.m. to 4 p.m., when UV radiation is most potent. Keep in mind that shade structures like parasols or canopies do not offer full protection. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.

Frequently asked questions

What is the usual temperature for Lancaster in May?

The high-temperature, in May, in Lancaster, records 21.3°C (70.3°F), while the low-temperature is 11.4°C (52.5°F).

What is the most humid month?

The most humid month is May, with an average relative humidity of 81%.

What is the average humidity in May?

In May, the average relative humidity is 81%.

How much does it rain in May?

In May, the rain falls for 17.8 days. Throughout May, 71mm (2.8") of precipitation is accumulated.

When it does not snow?

In Lancaster, snow does not fall in May through October.

Does it snow in May?

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

How many hours of daylight does Lancaster have in May?

The average day length in May is 14h and 25min.

What time are sunrise and sunset in May?

On the first day of May, sunrise is at 6:04 am and sunset at 8:00 pm. On the last day of the month, sunrise is at 5:38 am and sunset at 8:27 pm EDT.

How many hours of sunshine does Lancaster have in May?

In May, the average sunshine duration is 8.2h.

What is the month with the highest UV index?

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

What is the UV index reading in May?

The average daily maximum UV index in May is 6. A UV Index value of 6 to 7 symbolizes a high health vulnerability from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in May
Lancaster, PA

Average temperature in May - Lancaster, PA
  • Average high temperature in May: 21.3°C

The warmest month (with the highest average high temperature) is July (28.3°C).
The month with the lowest average high temperature is January (1.9°C).

  • Average low temperature in May: 11.4°C

The month with the highest average low temperature is July (18.2°C).
The coldest month (with the lowest average low temperature) is January (-4.9°C).

Average pressure in May
Lancaster, PA

Average pressure in May - Lancaster, PA
  • Average pressure in May: 1016.4mbar

The month with the highest atmospheric pressure is November (1020.4mbar).
The month with the lowest atmospheric pressure is June (1014mbar).

Average wind speed in May
Lancaster, PA

Average wind speed in May - Lancaster, PA
  • Average wind speed in May: 10.9km/h

The windiest month (with the highest average wind speed) is March (14.5km/h).
The calmest month (with the lowest average wind speed) is August (8.2km/h).

Average humidity in May
Lancaster, PA

Average humidity in May - Lancaster, PA
  • Average humidity in May: 81%

The month with the highest relative humidity is May (81%).
The month with the lowest relative humidity is April (76%).

Average rainfall in May
Lancaster, PA

Average rainfall in May - Lancaster, PA
  • Average rainfall in May: 71mm

The wettest month (with the highest rainfall) is August (85mm).
The driest months (with the least rainfall) are February and September (48mm).

Average rainfall days in May
Lancaster, PA

Average rainfall days in May - Lancaster, PA
  • Average rainfall days in May: 17.8 days

The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is February (8 days).

Average snowfall in May
Lancaster, PA

Average snowfall in May - Lancaster, PA
  • Average snowfall in May: 0mm

The month with the highest snowfall is March (93mm).
The months with the least snowfall are May, June, July, August, September and October (0mm).

Average snowfall days in May
Lancaster, PA

Average snowfall days in May - Lancaster, PA
  • Average snowfall days in May: 0 days

The month with the highest number of snowfall days is January (6.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight in May /
Average sunshine in May
Lancaster, PA

Average daylight in May / Average sunshine in May - Lancaster, 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 1min

The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).

Average sunshine days in May
Lancaster, PA

Average sunshine days in May - Lancaster, PA
  • Average sunshine days in May: 11.3 days

The month with the most sunshine days is November (19.4 days).
The month with the least sunshine days is May (11.3 days).

Average UV index in May
Lancaster, PA

Average UV index in May - Lancaster, 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
Lancaster, PA

Average cloud cover in May - Lancaster, PA
  • Average cloud cover in May: 48

The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 33).

Average visibility in May
Lancaster, PA

Average visibility in May - Lancaster, PA
  • Average visibility in May: 8km

The months with the highest visibility are January, February, March, April, June, July, October, November and December (9km).
The months with the lowest visibility are May, August and September (8km).

Lancaster, Pennsylvania, USA

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