This report describes the typical weather at the Juneau International Airport (Juneau, Alaska, United States) weather station over the course of an average June. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
Juneau, Alaska has a mild humid temperate climate with warm summers and no dry season. The area within 25 mi of this station is covered by tundra (37%), oceans and seas (34%), and forests (28%).
The month of June is characterized by gradually rising daily high temperatures, with daily highs increasing from 59°F to 63°F over the course of the month, exceeding 73°F or dropping below 51°F only one day in ten.
Over the course of June, the length of the day is essentially constant. The shortest day of the month is June 1 with 17:50 hours of daylight; the longest day is June 18 with 18:17 hours of daylight.
The earliest sunrise is at 3:50am on June 14; the latest sunset is at 10:10pm on June 26; the latest sunrise is at 4:02am on June 1; the earliest sunset is at 9:52pm on June 1.
Daylight saving time is observed in 2012 but it neither starts nor ends in June, so the entire month is in daylight time.
The median cloud cover is 100% (overcast) and does not vary substantially over the course of the month.
On June 15, a representative day, the sky is clear or mostly clear 15% of the time, partly cloudy 10% of the time, and mostly cloudy or overcast 75% of the time.
The average probability that some form of precipitation will be observed in a given day is 66%, with little variation over the course of the month.
Throughout June, the most common forms of precipitation are light rain and moderate rain.
Light rain is the most severe precipitation observed during 69% of those days with precipitation. It is most likely around June 14, when it is observed during 46% of all days.
Moderate rain is the most severe precipitation observed during 24% of those days with precipitation. It is most likely around June 27, when it is observed during 18% of all days.
Either snow is exceptionally unlikely to fall at this location in June or this station does not reliably report precipitation types.
The relative humidity typically ranges from 56% (mildly humid) to 94% (very humid) over the course of a typical June, rarely dropping below 34% (comfortable) and reaching as high as 100% (very humid).
The air is driest around June 1, at which time the relative humidity drops below 68% (mildly humid) three days out of four; it is most humid around June 1, rising above 91% (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 June, the dew point typically varies from 40°F (dry) to 52°F (very comfortable) and is rarely below 34°F (dry) or above 56°F (comfortable).
Over the course of June typical wind speeds vary from 0 mph to 13 mph (calm to moderate breeze), rarely exceeding 21 mph (fresh breeze).
The highest average wind speed of 7 mph (light breeze) occurs around June 3, at which time the average daily maximum wind speed is 13 mph (moderate breeze).
The lowest average wind speed of 7 mph (light breeze) occurs around June 29, at which time the average daily maximum wind speed is 12 mph (moderate breeze).