This report describes the typical weather at the Marine Corps Air Ground Combat Center Twentynine Palms (Twentynine Palms, California, United States) weather station over the course of an average year. It is based on the historical records from 1987 to 2012. Earlier records are either unavailable or unreliable.
Twentynine Palms, California has a hot desert climate. The area within 25 mi of this station is covered by shrublands (98%).
Over the course of a year, the temperature typically varies from 38°F to 103°F and is rarely below 32°F or above 109°F.
The warm season lasts from June 6 to September 18 with an average daily high temperature above 94°F. The hottest day of the year is July 22, with an average high of 103°F and low of 79°F.
The cold season lasts from November 20 to March 1 with an average daily high temperature below 68°F. The coldest day of the year is December 27, with an average low of 38°F and high of 59°F.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 9:51 hours of daylight; the longest day is June 20 with 14:26 hours of daylight.
The earliest sunrise is at 5:32am on June 13 and the latest sunset is at 8:01pm on June 28. The latest sunrise is at 7:07am on November 3 and the earliest sunset is at 4:34pm on December 6.
Daylight saving time (DST) is observed in this location during 2012, starting in the spring on March 11 and ending in the fall on November 4.
The median cloud cover ranges from 12% (mostly clear) to 41% (partly cloudy). The sky is cloudiest on February 1 and clearest on June 18. The clearer part of the year begins around April 27. The cloudier part of the year begins around November 22.
On June 18, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 66% of the time, and overcast or mostly cloudy 8% of the time.
On February 1, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 42% of the time, and clear or mostly clear 35% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around August 7, occurring in 14% of days. Precipitation is least likely around May 31, occurring in 3% of days.
Over the entire year, the most common forms of precipitation are light rain and thunderstorms.
Light rain is the most severe precipitation observed during 51% of those days with precipitation. It is most likely around February 1, when it is observed during 10% of all days.
Thunderstorms are the most severe precipitation observed during 36% of those days with precipitation. They are most likely around August 6, when it is observed during 11% of all days.
During the warm season, which lasts from June 6 to September 18, there is a 9% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of thunderstorms (76% of days with precipitation have at worst thunderstorms) and light rain (19%).
During the cold season, which lasts from November 20 to March 1, there is a 9% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of light rain (74% of days with precipitation have at worst light rain) and moderate rain (14%).
Either snow is exceptionally unlikely to fall at any time during the year at this location or this station does not reliably report precipitation types.
The relative humidity typically ranges from 16% (dry) to 81% (humid) over the course of the year, rarely dropping below 6% (very dry) and reaching as high as 100% (very humid).
The air is driest around June 22, at which time the relative humidity drops below 17% (dry) three days out of four; it is most humid around December 22, exceeding 64% (mildly 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 year, the dew point typically varies from 18°F (dry) to 56°F (comfortable) and is rarely below 4°F (dry) or above 68°F (muggy).
The time of the year between July 3 and September 11 is the most comfortable, with dew points that are neither too dry nor too muggy.
Over the course of the year typical wind speeds vary from 0 mph to 19 mph (calm to fresh breeze), rarely exceeding 31 mph (high wind).
The highest average wind speed of 11 mph (gentle breeze) occurs around May 28, at which time the average daily maximum wind speed is 18 mph (fresh breeze).
The lowest average wind speed of 6 mph (light breeze) occurs around November 26, at which time the average daily maximum wind speed is 11 mph (gentle breeze).