Average Weather in Southglenn Colorado, United States
In Southglenn, the summers are warm, the winters are very cold and dry, and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 22°F to 87°F and is rarely below 6°F or above 95°F.
Based on the tourism score, the best time of year to visit Southglenn for warm-weather activities is from mid June to early September.
The hot season lasts for 3.2 months, from June 7 to September 14, with an average daily high temperature above 78°F. The hottest day of the year is July 10, with an average high of 87°F and low of 61°F.
The cold season lasts for 3.5 months, from November 20 to March 3, with an average daily high temperature below 52°F. The coldest day of the year is December 30, with an average low of 22°F and high of 43°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 Southglenn, 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 Southglenn begins around June 4 and lasts for 5.0 months, ending around November 3. On September 16, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 75% of the time, and overcast or mostly cloudy 25% of the time.
The cloudier part of the year begins around November 3 and lasts for 7.0 months, ending around June 4. On May 7, the cloudiest day of the year, the sky is overcast or mostly cloudy 47% of the time, and clear, mostly clear, or partly cloudy 53% 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 Southglenn varies throughout the year.
The wetter season lasts 5.0 months, from April 5 to September 4, with a greater than 18% chance of a given day being a wet day. The chance of a wet day peaks at 32% on August 4.
The drier season lasts 7.0 months, from September 4 to April 5. The smallest chance of a wet day is 5% on December 19.
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 in Southglenn changes throughout the year.
Rain alone is the most common for 8.6 months, from February 27 to November 15. The highest chance of a day with rain alone is 32% on August 4.
Snow alone is the most common for 3.3 months, from November 19 to February 27. The highest chance of a day with snow alone is 4% on February 2.
Mixed snow and rain is the most common for 4.0 days, from November 15 to November 19. The highest chance of a day with mixed snow and rain is 6% on April 2.
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. Southglenn experiences some seasonal variation in monthly rainfall.
The rainy period of the year lasts for 7.3 months, from March 16 to October 25, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around May 16, with an average total accumulation of 1.8 inches.
The rainless period of the year lasts for 4.7 months, from October 25 to March 16. The least rain falls around December 29, with an average total accumulation of 0.0 inches.
Average Monthly Rainfall
We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.
As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Southglenn experiences some seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 6.7 months, from October 7 to April 29, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around March 24, with an average total liquid-equivalent accumulation of 0.3 inches.
The snowless period of the year lasts for 5.3 months, from April 29 to October 7. The least snow falls around July 20, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in Southglenn varies significantly over the course of the year. In 2018, the shortest day is December 21, with 9 hours, 22 minutes of daylight; the longest day is June 21, with 14 hours, 58 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:31 AM on June 14, and the latest sunrise is 1 hour, 59 minutes later at 7:30 AM on November 3. The earliest sunset is at 4:35 PM on December 7, and the latest sunset is 3 hours, 56 minutes later at 8:31 PM on June 27.
Daylight saving time (DST) is observed in Southglenn during 2018, starting in the spring on March 11, lasting 7.8 months, and ending in the fall on November 4.
Sunrise & Sunset with Twilight and Daylight Saving Time
The perceived humidity level in Southglenn, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.
Humidity Comfort Levels
The average hourly wind speed in Southglenn experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 5.8 months, from November 16 to May 9, with average wind speeds of more than 8.4 miles per hour. The windiest day of the year is April 1, with an average hourly wind speed of 9.7 miles per hour.
The calmer time of year lasts for 6.2 months, from May 9 to November 16. The calmest day of the year is August 19, with an average hourly wind speed of 7.1 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Southglenn is from the west throughout the year.
Best Time of Year to Visit
To characterize how pleasant the weather is in Southglenn throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Southglenn for general outdoor tourist activities is from mid June to early September, with a peak score in the first week of July.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Southglenn for hot-weather activities is from late June to early August, with a peak score in the second week of July.
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
The growing season in Southglenn typically lasts for 5.4 months (164 days), from around April 30 to around October 11, rarely starting before April 9 or after May 18, and rarely ending before September 20 or after November 1.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms in Southglenn should appear around March 27, only rarely appearing before March 10 or after April 15.
Growing Degree Days
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 2.8 months, from May 8 to August 3, with an average daily incident shortwave energy per square meter above 6.8 kWh. The brightest day of the year is June 21, with an average of 7.9 kWh.
The darker period of the year lasts for 3.2 months, from November 3 to February 10, with an average daily incident shortwave energy per square meter below 3.6 kWh. The darkest day of the year is December 21, with an average of 2.5 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Southglenn are 39.587 deg latitude, -104.953 deg longitude, and 5,594 ft elevation.
The topography within 2 miles of Southglenn contains only modest variations in elevation, with a maximum elevation change of 387 feet and an average elevation above sea level of 5,605 feet. Within 10 miles contains only modest variations in elevation (1,473 feet). Within 50 miles contains very significant variations in elevation (9,505 feet).
The area within 2 miles of Southglenn is covered by artificial surfaces (90%), within 10 miles by artificial surfaces (48%) and shrubs (29%), and within 50 miles by grassland (36%) and trees (28%).
This report illustrates the typical weather in Southglenn, 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 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Southglenn.
For each station, the records are corrected for the elevation difference between that station and Southglenn 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 Southglenn is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Southglenn and a given station.
The stations contributing to this reconstruction are: Arapahoe County Airport (68%, 9 kilometers, east); Denver / Stapleton International, Co. (30%, 20 kilometers, north); Wilkerson Pass (1.2%, 77 kilometers, southwest); and Copper Mountain, Red Cliff Pass (0.9%, 104 kilometers, west).
Time zones for aiports and weather stations are provided by AskGeo.com .