Average Weather in Tucson Arizona, United States
In Tucson, the summers are sweltering, the winters are cool and dry, and it is mostly clear year round. Over the course of the year, the temperature typically varies from 42°F to 102°F and is rarely below 33°F or above 107°F.
The hot season lasts for 3.7 months, from May 25 to September 17, with an average daily high temperature above 94°F. The hottest day of the year is June 29, with an average high of 102°F and low of 75°F.
The cool season lasts for 3.2 months, from November 21 to February 28, with an average daily high temperature below 72°F. The coldest day of the year is January 4, with an average low of 42°F and high of 65°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
In Tucson, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in Tucson begins around March 15 and lasts for 3.7 months, ending around July 7. On June 13, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 85% of the time, and overcast or mostly cloudy 15% of the time.
The cloudier part of the year begins around July 7 and lasts for 8.3 months, ending around March 15. On July 30, the cloudiest day of the year, the sky is overcast or mostly cloudy 45% of the time, and clear, mostly clear, or partly cloudy 55% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Tucson varies significantly throughout the year.
The wetter season lasts 2.1 months, from July 5 to September 8, with a greater than 23% chance of a given day being a wet day. The chance of a wet day peaks at 42% on August 4.
The drier season lasts 9.9 months, from September 8 to July 5. The smallest chance of a wet day is 3% on May 20.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 42% on August 4.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Tucson experiences significant seasonal variation in monthly rainfall.
The rainy period of the year lasts for 9.4 months, from June 20 to April 1, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around July 31, with an average total accumulation of 2.2 inches.
The rainless period of the year lasts for 2.6 months, from April 1 to June 20. The least rain falls around May 28, with an average total accumulation of 0.1 inches.
Average Monthly Rainfall
The length of the day in Tucson varies significantly over the course of the year. In 2017, the shortest day is December 21, with 10 hours, 2 minutes of daylight; the longest day is June 20, with 14 hours, 16 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:16 AM on June 12, and the latest sunrise is 2 hours, 9 minutes later at 7:25 AM on January 8. The earliest sunset is at 5:18 PM on December 3, and the latest sunset is 2 hours, 16 minutes later at 7:34 PM on June 30.
Daylight saving time (DST) is not observed in Tucson during 2017.
Sunrise & Sunset with Twilight
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
Tucson experiences some seasonal variation in the perceived humidity.
The muggier period of the year lasts for 2.7 months, from June 29 to September 20, during which time the comfort level is muggy, oppressive, or miserable at least 5% of the time. The muggiest day of the year is August 5, with muggy conditions 21% of the time.
The least muggy day of the year is December 4, when muggy conditions are essentially unheard of.
Humidity Comfort Levels
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed in Tucson experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 9.4 months, from September 23 to July 3, with average wind speeds of more than 3.7 miles per hour. The windiest day of the year is April 22, with an average hourly wind speed of 4.7 miles per hour.
The calmer time of year lasts for 2.7 months, from July 3 to September 23. The calmest day of the year is August 8, with an average hourly wind speed of 2.9 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Tucson varies throughout the year.
The wind is most often from the west for 6.8 months, from February 18 to September 11, with a peak percentage of 56% on June 9. The wind is most often from the east for 5.2 months, from September 11 to February 18, with a peak percentage of 46% on January 1.
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.
The brighter period of the year lasts for 2.6 months, from April 16 to July 5, with an average daily incident shortwave energy per square meter above 7.5 kWh. The brightest day of the year is June 7, with an average of 8.6 kWh.
The darker period of the year lasts for 3.1 months, from November 5 to February 9, with an average daily incident shortwave energy per square meter below 4.4 kWh. The darkest day of the year is December 24, with an average of 3.4 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Tucson are 32.222 deg latitude, -110.926 deg longitude, and 2,470 ft elevation.
The topography within 2 miles of Tucson contains only modest variations in elevation, with a maximum elevation change of 141 feet and an average elevation above sea level of 2,476 feet. Within 10 miles contains only modest variations in elevation (4,081 feet). Within 50 miles also contains extreme variations in elevation (7,858 feet).
The area within 2 miles of Tucson is covered by artificial surfaces (83%) and shrubs (13%), within 10 miles by shrubs (72%) and artificial surfaces (27%), and within 50 miles by shrubs (87%).
This report illustrates the typical weather in Tucson, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Tucson.
For each station, the records are corrected for the elevation difference between that station and Tucson according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Tucson is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Tucson and a given station.
The stations contributing to this reconstruction are: Allied Airstrip (51%, 7 kilometers, southeast); Tucson International Airport (48%, 10 kilometers, south); and Casa Grande Municipal Airport (1.3%, 113 kilometers, northwest).
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for aiports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.