Denver Climatological Preview - July 2023

A Preview of Thornton's July Weather - A Hot and Stormy Month

Change is of course the one constant in Denver's weather but come July, things actually get pretty consistent.

The standard formula for a day in July is a sunning morning, clouds developing in the late morning and early afternoon. Come mid-afternoon, thunderstorms are rolling off of the foothills and into the metro area and the eastern plains. These storms do occasionally reach severe status containing hail, gusty winds and heavy downpours of rain.

In fact, the worst hail storm on record in Denver history hit western sections of the city on July 11th, 1990. Baseball and softball sized hail from this ferocious storm caused millions of dollars worth of property damage.

July is the most stormy month of the year in fact with thunderstorms occurring on average 11 days per month - or once every three days. These slow moving storms are one of the reasons July is Denver's second rainiest month with an average of 2.16 inches of rain (second only to May).

However, these storms are also often very localized and cause widely varying precipitation amounts across the metro area. It is not unusual for one area of down to be deluged while others remain entirely dry. With these severe storms, flash flooding remains a possibility.

Being our hottest month, the average monthly temperature for July is 74.2 degrees.Temperatures have ranged from a record high of 105 degrees on July 20, 2005 down to a record low temperature of 42 degrees on July 31, 1873.

July high temps average 89.4 degrees and this is the month when we typically see the most consecutive days above 90 degrees. 25 times streaks of 10 or more consecutive days above 90 degrees have been recorded entirely in July or at least partially starting in June or ending in August. Average highs range from 87 degrees on the first of the month and climb to 90 degrees by the end of the month.

Low temperatures during the month average 58.9 degrees. The month kicks off with an average low of 57 degrees and ends with a normal of 60 degrees.

Two record 90 degree heat streaks stand out, both 24 days in length. These two were the longest 90 degree streaks in Denver history and occurred July 11 to August 3, 2012 and July 13 to August 5, 2008.

The summer of 2012 was also notable for Denver having recorded a total of 73 days with temperatures at or above 90 degrees. This easily bested the previous record-holder of 61 90 degrees in 2000.

July Extremes

JULY: Dever's Top 5 Coldest (mean temperatures):

78.9 degrees 2012 *** Warmest month is Denver history 1872-2012
77.8 degrees 1934
77.7 degrees 2005
77.6 degrees 2008
77.3 degrees 1936

JULY: Dever's Top 5 Warmest (mean temperatures):

67.4 degrees 1895
68.2 degrees 1906
68.7 degrees 1915
68.8 degrees 1904
68.9 degrees 1891 & 1950

JULY: Denver's Wettest

6.41 inches 1965
5.92 inches 1998
5.60 inches 1997
5.24 inches 1919
4.75 inches 2001

JULY: Denver's Driest

0.01 inches 1901
0.08 inches 1939
0.24 inches 2008
0.27 inches 2005
0.31 inches 1917

Outlook for July 2023

The Climate Prediction Center 's long range forecast point to a possible continuation of the cool, wet weather of recent months. The agency's outlook gives northeastern Colorado an above normal chance of seeing temperatures below average and precipitation levels above average.

For More Information

Temperature Normals and Extremes for July

Monthly Temperature, Rainfall and Snowfall Extremes for July

JULY AVERAGE STATISTICS * Normals & Means, 1981 - 2010

TEMPERATURE
AVERAGE HIGH	89.4
AVERAGE LOW	58.9
MONTHLY MEAN	74.2
DAYS WITH HIGH 90 OR ABOVE	16
DAYS WITH HIGH 32 OR BELOW	0
DAYS WITH LOW 32 OR BELOW	0
DAYS WITH LOWS ZERO OR BELOW	0

PRECIPITATION
MONTHLY MEAN	2.16 INCHES
DAYS WITH MEASURABLE PRECIPITATION	8
AVERAGE SNOWFALL	0
DAYS WITH 1.0 INCH OR MORE SNOWFALL	0

MISCELLANEOUS JULY AVERAGES
HEATING DEGREE DAYS	6
COOLING DEGREES DAYS	289
WIND SPEED (MPH)	8.3 MPH
WIND DIRECTION	SOUTH
DAYS WITH THUNDERSTORMS	11
DAYS WITH DENSE FOG	0* (Less than 1)
PERCENT OF SUNSHINE POSSIBLE	71

JULY EXTREMES
RECORD HIGH	105 ON 7/20/2005 (TIES AS HOTTEST DENVER TEMPERATURE)
RECORD LOW	42 ON 7/4/1903 AND 7/31/1873
WARMEST	78.9 IN 2012
COLDEST	67.4 IN 1895
WETTEST	6.41 INCHES IN 1965
MAXIMUM 24 HOUR MOISTURE	3.43 INCHES IN 1951
DRIEST	0.01 IN 1901
SNOWIEST (Could include hail)	NO SNOWFALL EVER RECORDED IN JULY
LEAST SNOWIEST	NO SNOWFALL EVER RECORDED IN JULY

* Historical weather statistics gathered from the National Weather Service's Denver / Boulder forecast office data archives.