Average Weather In May For Kirkwall, United Kingdom

Location

This report describes the typical weather at the Kirkwall Airport (Kirkwall, United Kingdom) weather station over the course of an average May. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.

Kirkwall has a mild humid temperate climate with warm summers and no dry season. The area within 25 mi of this station is covered by oceans and seas (82%) and grasslands (16%).

Temperature

The month of May is characterized by gradually rising daily high temperatures, with daily highs increasing from 50°F to 55°F over the course of the month, exceeding 60°F or dropping below 45°F only one day in ten.

Daily High and Low Temperature in May

The daily average low (blue) and high (red) temperature with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).
Daily low temperatures range from 41°F to 45°F, falling below 35°F or exceeding 49°F only one day in ten.

Fraction of Time Spent in Various Temperature Bands in May

The average fraction of time spent in various temperature bands: frigid (below 15°F), freezing (15°F to 32°F), cold (32°F to 50°F), cool (50°F to 65°F), comfortable (65°F to 75°F), warm (75°F to 85°F), hot (85°F to 100°F) and sweltering (above 100°F).

Sun

Over the course of May, the length of the day is very rapidly increasing. From the start to the end of the month, the length of the day increases by 2:05 hours, implying an average day-over-day increase of 4.0 minutes.

The shortest day of the month is May 1 with 15:52 hours of daylight; the longest day is May 31 with 17:57 hours of daylight.

Daily Hours of Daylight and Twilight in May

The number of hours during which the Sun is visible (black line), with various degrees of daylight, twilight, and night, indicated by the color bands. From bottom (most yellow) to top (most gray): full daylight, solar twilight (Sun is visible but less than 6° from the horizon), civil twilight (Sun is not visible but is less than 6° below the horizon), nautical twilight (Sun is between 6° and 12° below the horizon), astronomical twilight (Sun is between 12° and 18° below the horizon), and full night.

The earliest sunrise is at 4:12am on May 30; the latest sunset is at 10:09pm on May 31; the latest sunrise is at 5:13am on May 1; the earliest sunset is at 9:05pm on May 1.

Daylight saving time is observed in 2012 but it neither starts nor ends in May, so the entire month is in daylight time.

Daily Sunrise & Sunset with Twilight and Daylight Saving Time in May

The solar day over the course of the year 2012 . From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (solar, civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray. The transitions to and from daylight saving time are indicated by the "DST" labels.

Clouds

The median cloud cover is 83% (mostly cloudy) and does not vary substantially over the course of the month.

Median Cloud Cover in May

The median daily cloud cover (black line) with percentile bands (inner band from 40th to 60th percentile, outer band from 25th to 75th percentile).

On May 16, a representative day, the sky is clear or mostly clear 20% of the time, partly cloudy 24% of the time, and mostly cloudy or overcast 48% of the time.

Cloud Cover Types in May

The fraction of time spent in each of the five sky cover categories. From top (most blue) to bottom (most gray), the categories are clear, mostly clear, partly cloudy, mostly cloudy, and overcast. Pink indicates missing data. Outside of the United States clear skies are often reported ambiguously, leading them to be lumped in with the missing data.

Precipitation

The average probability that some form of precipitation will be observed in a given day is 74%, with little variation over the course of the month.

Probability of Precipitation at Some Point in the Day in May

The fraction of days in which various types of precipitation are observed. If more than one type of precipitation is reported in a given day, the more severe precipitation is counted. For example, if light rain is observed in the same day as a thunderstorm, that day counts towards the thunderstorm totals. The order of severity is from the top down in this graph, with the most severe at the bottom.

Throughout May, the most common forms of precipitation are moderate rain and light rain.

Moderate rain is the most severe precipitation observed during 66% of those days with precipitation. It is most likely around May 31, when it is observed during 50% of all days.

Light rain is the most severe precipitation observed during 16% of those days with precipitation. It is most likely around May 29, when it is observed during 13% of all days.

Types of Precipitation Throughout May

Relative frequency of various types of precipitation over the course of a typical May.

Snow

The likelihood of snow falling is highest around May 1, occurring in 10% of days.

Probability of Snow Fall Being Reported in a Given Day in May

Probability that snow will be reported at least once in a given day.

Either snow rarely accumulates at this location in May or snow depth measurements are unavailable or unreliable.

Humidity

The relative humidity typically ranges from 66% (mildly humid) to 96% (very humid) over the course of a typical May, rarely dropping below 52% (mildly humid) and reaching as high as 100% (very humid).

The air is driest around May 11, at which time the relative humidity drops below 74% (humid) three days out of four; it is most humid around May 30, rising above 94% (very humid) three days out of four.

Relative Humidity in May

The average daily high (blue) and low (brown) relative humidity with percentile bands (inner bands from 25th to 75th percentile, outer bands from 10th to 90th percentile).

Dew Point

Dew point is often a better measure of how comfortable a person will find the weather than relative humidity because it more directly relates to whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid.

Over the course of a typical May, the dew point typically varies from 36°F (dry) to 48°F (dry) and is rarely below 28°F (dry) or above 54°F (very comfortable).

Dew Point in May

The daily average low (blue) and high (red) dew point with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).

Wind

Over the course of May typical wind speeds vary from 5 mph to 21 mph (light breeze to fresh breeze), rarely exceeding 30 mph (strong breeze).

The highest average wind speed of 14 mph (moderate breeze) occurs around May 1, at which time the average daily maximum wind speed is 21 mph (fresh breeze).

The lowest average wind speed of 13 mph (moderate breeze) occurs around May 29, at which time the average daily maximum wind speed is 19 mph (fresh breeze).

Wind Speed in May

The average daily minimum (red), maximum (green), and average (black) wind speed with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).
The wind is most often out of the south (21% of the time), west (20% of the time), south west (13% of the time), south east (12% of the time), and north (10% of the time).

Wind Directions in May

The fraction of time spent with the wind blowing from the various directions over the entire year. Values do not sum to 100% because the wind direction is undefined when the wind speed is zero.

Fraction of Time Spent with Various Wind Directions in May

The fraction of time spent with the wind blowing from the various directions on a daily basis. Stacked values do not always sum to 100% because the wind direction is undefined when the wind speed is zero.