This report describes the typical weather at the Palmer Municipal Airport (Palmer, Alaska, United States) weather station over the course of an average May. It is based on the historical records from 1981 to 2012. Earlier records are either unavailable or unreliable.
Palmer, Alaska has a continental climate with short dry cool summers. The area within 25 mi of this station is covered by tundra (45%), forests (35%), shrublands (12%), oceans and seas (3%), and lakes and rivers (2%).
The month of May is characterized by rising daily high temperatures, with daily highs increasing from 53°F to 61°F over the course of the month, exceeding 69°F or dropping below 47°F only one day in ten.
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 2:32 hours, implying an average day-over-day increase of 4.9 minutes.
The shortest day of the month is May 1 with 16:21 hours of daylight; the longest day is May 31 with 18:54 hours of daylight.
The earliest sunrise is at 4:29am on May 31; the latest sunset is at 11:22pm on May 31; the latest sunrise is at 5:44am on May 1; the earliest sunset is at 10:05pm 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.
The median cloud cover ranges from 77% (partly cloudy) to 85% (mostly cloudy). The trend is for the sky to be becoming cloudier with the median cloud cover increasing by 8% from the start to the end of the month.
On May 16, a representative day, the sky is clear or mostly clear 19% of the time, partly cloudy 10% of the time, and mostly cloudy or overcast 44% of the time.
The probability that precipitation will be observed at this location varies throughout the month. Precipitation is most likely around May 31, occurring in 27% of days. Precipitation is least likely around May 1, occurring in 21% of days.
Throughout May, the most common forms of precipitation are light rain.
Light rain is the most severe precipitation observed during 76% of those days with precipitation. It is most likely around May 31, when it is observed during 22% of all days.
The likelihood of snow falling is highest around May 1, occurring in 7% of days.
Either snow rarely accumulates at this location in May or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 37% (comfortable) to 93% (very humid) over the course of a typical May, rarely dropping below 26% (dry) and reaching as high as 100% (very humid).
The air is driest around May 10, at which time the relative humidity drops below 43% (comfortable) three days out of four; it is most humid around May 31, rising above 87% (very humid) three days out of four.
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 25°F (dry) to 41°F (dry) and is rarely below 18°F (dry) or above 47°F (dry).
Over the course of May typical wind speeds vary from 0 mph to 15 mph (calm to moderate breeze), rarely exceeding 24 mph (strong breeze).
The highest average wind speed of 9 mph (gentle breeze) occurs around May 19, at which time the average daily maximum wind speed is 15 mph (moderate breeze).
The lowest average wind speed of 8 mph (gentle breeze) occurs around May 31, at which time the average daily maximum wind speed is 15 mph (moderate breeze).