This report describes the typical weather at the Phoenix Deer Valley Airport (Phoenix, Arizona, United States) weather station over the course of an average October. It is based on the historical records from 1997 to 2012. Earlier records are either unavailable or unreliable.
Phoenix, Arizona has a hot desert climate. The area within 25 mi of this station is covered by shrublands (86%), grasslands (8%), built-up areas (3%), and croplands (2%).
The month of October is characterized by rapidly falling daily high temperatures, with daily highs decreasing from 92°F to 79°F over the course of the month, exceeding 98°F or dropping below 68°F only one day in ten.
Over the course of October, the length of the day is gradually decreasing. From the start to the end of the month, the length of the day decreases by 59 minutes, implying an average day-over-day decrease of 1.9 minutes.
The shortest day of the month is October 31 with 10:50 hours of daylight; the longest day is October 1 with 11:49 hours of daylight.
The earliest sunrise is at 6:23am on October 1; the latest sunset is at 6:12pm on October 1; the latest sunrise is at 6:47am on October 31; the earliest sunset is at 5:37pm on October 31.
Daylight savings time (DST) is not observed in 2012.
The median cloud cover is 0% (clear) and does not vary substantially over the course of the month.
On October 16, a representative day, the sky is clear or mostly clear 86% of the time, partly cloudy 3% of the time, and mostly cloudy or overcast 7% of the time.
The probability that precipitation will be observed at this location varies throughout the month. Precipitation is most likely around October 1, occurring in 15% of days. Precipitation is least likely around October 27, occurring in 10% of days.
Throughout October, the most common forms of precipitation are thunderstorms, light rain, and moderate rain.
Thunderstorms are the most severe precipitation observed during 40% of those days with precipitation. They are most likely around October 1, when it is observed during 7% of all days.
Light rain is the most severe precipitation observed during 37% of those days with precipitation. It is most likely around October 1, when it is observed during 5% of all days.
Moderate rain is the most severe precipitation observed during 14% of those days with precipitation. It is most likely around October 9, when it is observed during 2% of all days.
Either snow is exceptionally unlikely to fall at this location in October or this station does not reliably report precipitation types.
The relative humidity typically ranges from 17% (dry) to 49% (comfortable) over the course of a typical October, rarely dropping below 9% (very dry), or exceeding 84% (humid).
The air is driest around October 3, at which time the relative humidity drops below 20% (dry) three days out of four; it is most humid around October 31, rising above 31% (comfortable) 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 October, the dew point typically varies from 29°F (dry) to 48°F (dry) and is rarely below 16°F (dry) or above 60°F (comfortable).
Over the course of October typical wind speeds vary from 0 mph to 12 mph (calm to moderate breeze), rarely exceeding 19 mph (fresh breeze).
The highest average wind speed of 6 mph (light breeze) occurs around October 1, at which time the average daily maximum wind speed is 12 mph (moderate breeze).
The lowest average wind speed of 5 mph (light breeze) occurs around October 31, at which time the average daily maximum wind speed is 11 mph (gentle breeze).