This report describes the typical weather at the Yellowstone Lake (Yellowstone National Park, Wyoming, United States) weather station over the course of an average August. It is based on the historical records from 2001 to 2012. Earlier records are either unavailable or unreliable.
Yellowstone National Park, Wyoming has a humid subarctic continental climate with cool summers and no dry season. The area within 25 mi of this station is covered by forests (90%) and lakes and rivers (7%).
The month of August is characterized by falling daily high temperatures, with daily highs decreasing from 71°F to 65°F over the course of the month, exceeding 77°F or dropping below 55°F only one day in ten.
Over the course of August, the length of the day is decreasing. From the start to the end of the month, the length of the day decreases by 1:22 hours, implying an average day-over-day decrease of 2.7 minutes.
The shortest day of the month is August 31 with 13:15 hours of daylight; the longest day is August 1 with 14:37 hours of daylight.
The earliest sunrise is at 6:09am on August 1; the latest sunset is at 8:47pm on August 1; the latest sunrise is at 6:44am on August 31; the earliest sunset is at 7:59pm on August 31.
Daylight saving time is observed in 2012 but it neither starts nor ends in August, so the entire month is in daylight time.
This weather station does not reliably report sky cover.
There is either very little precipitation at this location in August, or the weather station does not reliably report the conditions.
Either snow is exceptionally unlikely to fall at this location in August or this station does not reliably report precipitation types.
The relative humidity typically ranges from 26% (dry) to 89% (very humid) over the course of a typical August, rarely dropping below 14% (very dry) and reaching as high as 98% (very humid).
The air is driest around August 6, at which time the relative humidity drops below 30% (comfortable) three days out of four; it is most humid around August 1, rising above 85% (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 August, the dew point typically varies from 27°F (dry) to 46°F (dry) and is rarely below 19°F (dry) or above 52°F (very comfortable).
Over the course of August typical wind speeds vary from 0 mph to 10 mph (calm to gentle breeze), rarely exceeding 14 mph (moderate breeze).
The highest average wind speed of 4 mph (light breeze) occurs around August 6, at which time the average daily maximum wind speed is 10 mph (gentle breeze).
The lowest average wind speed of 3 mph (light breeze) occurs around August 29, at which time the average daily maximum wind speed is 9 mph (gentle breeze).