CLIMATE OF PHOENIX, ARIZONA: An Abridged On-Line Version of NOAA Technical Memorandum NWS WR-177

by

Robert J. Schmidli

Weather Service Forecast Office
Phoenix, Arizona

First Printed April 1969 as WR-38
Revised and Reprinted as WR-177, March 1983 and
December 1986

May 1996 (Revised)
On-Line Version by R.S. Cerveny, Office of Climatology, ASU (December, 1996)



This publication has been reviewed and is approved for publication by Scientific Services Division, Western Region.

CONTENTS


Abstract
General Geographical and Climatological Summary
Climatological Summary by Month
History of Weather Observations
Elevations at National Weather Service Forecast Office

Temperature
Normal Maximum, Minimum and Mean by Months

  • Highest Mean and Lowest Mean by Months and Year of Occurrence
  • Highest and Lowest Mean Maximum and Highest and Lowest
  • Greatest # of Consecutive Months Above and Below Normal
  • Highest Maximum and Lowest Minimum by Months and Day and Year of Occurrence
  • Lowest Maximum and Highest Minimum by Months and Day and Year of Occurrence
  • Greatest and Least Monthly Temperature Range by Months and year of Occurrence
  • Hottest and Coolest Summers and Warmest and Coldest Winters
  • Hottest 3 and 2 Consecutive Months
  • Hottest Single Months
  • Warmest & Coldest Winters
  • Coldest 2 consecutive and Single Months Humidity

    Dew Point Temperature
    Highest Hourly Dew Points
  • Highest Daily Dew Points
  • Highest Monthly Dew Points
  • Lowest Hourly Dew Points
  • Lowest Daily Dew Points
  • Lowest Monthly Dew Points
  • Lowest Relative Humidities
    Heat Index (Apparent Temperature)
  • Air Temperature / Relative Humidity
  • The Myth of Increasing Moisture Levels in Phoenix
  • Average Temperature & Relative Humidity in Percent by Five-Year Periods

  • Temperature Records
  • Average Number of Days of 100 or Higher by Months, and Earliest and Latest Date of Occurrence
  • Average Number of Days of 110 or Higher by Months and Earliest and Latest Date of Occurrence
  • Probability in Percent of Observing 100 or Higher, 105 or Higher, and 110 or Higher
  • Greatest Number of Consecutive Days with 120 or Higher, 115 or Higher, 110 or Higher, 105 or Higher, 100 or Higher, and 99 or Higher
  • Greatest Number of Consecutive Days with Maximum 75 or Lower, 60 or Lower, 55 or Lower, 50 or Lower, 45 or Lower, and 42 or Lower
  • Greatest Number of Days in One Year with Maximum 90 or Higher, 100 or Higher, 105 or Higher, 110 or Higher, 115 or Higher, and 120 or Higher
  • Least Number of Days in One Year with Maximum 90 or Higher, 100 or Higher, 105 or Higher, and 110 or Higher
  • Greatest Number of Consecutive Days with Minimum 35 or Lower, 32 or Lower, 30 or Lower, 28 or Lower, 25 or Lower, and 20 or Lower
  • Greatest Number of Days in One Winter with Minimum 32 or Lower, 28 or Lower, 24 or Lower, and 20 or Lower
  • Least Number of Days in One Winter with Minimum 32 or Lower
  • Greatest Number of Consecutive Days with Minimum 85 or Higher and 80 or Higher
  • Greatest Number of Days in One Year with Minimum 85 or Higher and 80 or Higher71
  • Greatest Number of Consecutive Days with Mean 100 or Higher
  • Greatest Number of Days in One Year with Mean 100 or Higher
  • Highest and Lowest Daily Mean
  • Greatest and Least Daily Temperature Range
  • Normal and Highest and Lowest Heating Degree Days by Months and Year of Occurrence (Base 65 Degrees)
  • Normal and Highest and Lowest Cooling Degree Days by Months and Year of Occurrence (Base of 65 Degrees)
  • Average and Highest and Lowest Cooling Degree Days by Months and Year of Occurrence (Base 80 Degrees)
  • Freeze and Growing Season Data

    Precipitation
    Normal Total and Maximum and Minimum Total by Months and Year of Occurrence
  • Years in Which There Were 5 (the most) Calendar Months Without Measurable Precipitation
  • Years in Which All Twelve Calendar Months had Measurable Precipitation
  • Daily Normals of Precipitation
  • Greatest Number of Days with Trace or More and 0.01 Inches or More by Months and Year of Occurrence and Average Number of Days with 0.01 Inches or More by Months
  • Greatest Number of Days with 0.10 Inches or More, 0.50 Inches or More, and 1.00 Inch or More by Months and Year of Occurrence
  • Maximum Amounts for 5, 10, 15, and 30 Minutes; 1, 2, and 24 Hours by Months and Day and Year of Occurrence
  • Greatest Number of Consecutive Days with Trace or More, 0.01 Inches or More, 0.25 Inches or More, 0.50 Inches or More, and 1.00 Inch or More
  • Greatest Number of Consecutive Days without Trace or More and without 0.01 Inches or More
  • Amounts and Dates of All Snowfalls
  • Daily Frequency of Occurrence in Percent of Trace or More, 0.01 Inches or More, 0.10 Inches or More, 0.25 Inches or More, 0.50 Inches or More, and 1.00 Inch or More
  • Frequency of Occurrence of 0.01 Inches or More on Consecutive Days
  • Estimated Return Periods for Short-Duration Precipitation
  • Monthly and Annual Precipitation, Monthly and Annual Greatest 24-hour Precipitation

    Thunderstorms, Hail & Tornadoes
    Arizona Monsoon: Discussion
  • Monsoon Statistics (Average Dates of Start, End, etc.)
  • Monsoon Start & End Dates: 1948-1995
  • Wettest & Driest Monsoons
  • Average Number of Days with Thunderstorms by Months and Average Number of Days with Hail by Months
  • Greatest Number of Days with Thunderstorms and Greatest Number of Days with Hail by Months and Year of Occurrence - 1896-1990
  • Frequency of Thunderstorm Occurrence in Percent by Days

    Lightning Information

    Description of Known Tornadoes and Funnel Clouds in the Greater Phoenix Area - 1955-1990

    Sunshine, Cloudiness, and Fog
    Average and Highest and Lowest Percentage of Possible Sunshine by Months and Year of Occurrence
  • Average Annual Percentage of Possible Sunshine at Phoenix as Compared to other Major U. S. Cities
  • Average Number of Clear, Partly Cloudy, Cloudy, and Heavy Fog Days by Months
  • Greatest Number of Consecutive Days with 100 Percent Sunshine and 0 Percent Sunshine

    Wind
    Average Speed and Prevailing Direction by Months and Peak Gust by Months and Day and Year of Occurrence
  • Mean Frequency of Occurrence of Peak Gusts by Months
  • Estimated Return Periods of Peak Wind Gusts by Months

    Pressure
  • Average and Highest and Lowest Station Pressure by Months and Day and Year of Occurrence
  • Highest and Lowest Sea-Level Pressure by Months and Day and Year of Occurrence
  • Normal 6-Hourly Pressure Changes in Inches

    Flying Weather
    Percentage Frequencies of Ceiling-Visibility
  • Frequencies of Visibility-Restricting Phenomena by Months

    Holiday Weather Information
  • Average Maximum and Minimum Temperature, Highest Maximum and Lowest Minimum and Year of Occurrence, and Frequency of .01 Inches or More of Precipitation in Percent on Various Holidays

    Weather Extremes
  • Weather Extremes of Temperature, Precipitation, Snowfall, Pressure, and Wind for Phoenix as Compared to Those of Arizona and United States