A Preview of Denver's April Weather - Something for Everyone

April marks a transition between winter and summer for most of the country but for Denver it is especially true as we can see a stunning variety of weather. The proverbial April showers are certainly a possibility for Denver. Snow? Tornadoes? Thunderstorms? You bet - all can happen! For good measure throw in a chance for hail and even dust storms and April gives every type of weather condition you could like - or hate.

The good news is that sunshine and warmer temperatures are usually in abundance as the normal highs during the month move up from 57 degrees on the first to 65 degrees on the 30th. It is not unusual to have a number of days well into the 70's and the low 80's. We also see the normal lows move above freezing from 30 degrees at the start of the month to 39 degrees by the end. Temperature extremes can hit both ends of the spectrum with a record low of 2 degrees below zero on April 2, 1975 and a record high of 90 degrees on April 30, 1992.

In terms of the extremes and severe weather we can see, at this time of year Denver can be hit from every direction with a wide variety of air masses. Cold can be brought on when Arctic air invades from the north and that can then team up with Pacific storms to produce snow. Thunderstorms can be generated when warm, moist air from the Gulf of Mexico moves into the area. Warmer temperatures and low humidity too can happen when warm, dry air from the desert southwest invade Colorado.

For snow lovers, April still gives us a good chance of the white stuff for it is actually our third snowiest month. The snowiest April was in 1933 when we received 33.8 inches of snow during the month. Way back on April 22 - 23, 1885, Denver was hit with 23 inches of snow, the most for a 24 hour period in April.

We are also reminded that we live on the wide open plains as it is our windiest month with an average speed of 10 miles per hour from the south. Typically we will have two thunderstorms in April and there is always the chance of severe thunderstorms which historically can include hail, severe damaging winds and / or tornadoes.

April 2001 brought on a reminder of the potential for severe winter weather when on the 10th and 11th a storm produced blizzard like conditions and 10 inches of snow was dumped on the former Stapleton International Airport site. Across the metro area heavy snow was recorded including 18 inches in southeast Aurora with 5 foot drifts, 16 inches with 3 foot drifts in Parker, 10 inches in Lafayette, 9 in Westminster and 8 in Littleton. But, as is typical in Colorado, by the 12th the sun had come out and the snow melted away quickly.

April showers are also common as was seen in 2007 when we set a 24 hour rain record. Between April 23rd and 24th of that year, 2.1 inches of rainfall was recorded at DIA obliterating the old record of 1.29 inches that was set way back in 1891. Further north here in Thornton we recorded a bit more precipitation over the same period with 2.32 inches of rain. Normally Denver receives 1.93 inches for the entire month! Were it not for that storm, the month would have been a very dry one as a mere 0.4 inches of rain fell otherwise in Thornton.

Looking Back - April 2010

A distinct lack of snow for what is traditionally Denver’s third snowiest month and slightly warmer than normal temperatures marked Denver’s April last year.

For the month Denver averaged a temperature of 47.8 degrees – 0.2 degrees above normal. By contrast, the warmest April on record occurred in 1981 with an average temperature of 56.4 degrees. The coldest, in 1920, had an average temperature of 38.8 degrees.

We saw a high temperature for the month of 79 degrees on the 28th and a low down to 26 degrees on the 2nd. Fifteen days saw lows dip below the freezing mark and all of the high temperatures climbed to 32 degrees or higher.

Here in Thornton our average temperature of 48.1 degrees was slightly warmer than the official Denver measurement. Our warmest day was 79.4 degrees on the 28th and the coldest occurred on the 2nd when the mercury dipped to 24.3 degrees.

Snowfall was dismal for the month with only 0.5 inch recorded at Denver International Airport. This tied with 1896 as the fifth least snowiest April on record.

Thornton topped the official Denver snowfall total considerably as we recorded 3.1 inches during the month. All of that fell on a single day on the 7th.

The month was looking like it would be similarly dry with little precipitation but the final third of the month provided relief. From the 21st to the 25th 2.31 inches of precipitation was recorded at DIA. The month wrapped up with 2.51 inches total precipitation – 0.58 inch above the normal of 1.93 inches for April. While precipitation was a good ways above normal, it was not enough to reach ‘top 10’ status for wettest Aprils.

Here again Thornton was wetter than Denver as we saw 2.75 inches of precipitation fall into our rain bucket. The greatest single day amount was recorded on the 22nd when 0.72 inch fell into our bucket.

In all, eight days during April 2010 saw measurable precipitation at DIA. Two days saw 0.5 inch or more. The greatest 24 hour amount of precipitation occurred between the 22nd and 23rd when 1.57 inches was recorded.

Click here to view Thornton's April 2010 Climatology Report.

April 2011 Outlook

The National Weather Service 30-day outlook model forecasts a continuing warm and dry pattern with above normal temperatures and below normal precipitation.

For More Information

Temperature Normals and Extremes for April

Monthly Temperature, Rainfall and Snowfall Extremes for April

APRIL AVERAGE STATISTICS * Normals & Means, 1971 - 2000
TEMPERATURE
AVERAGE HIGH	60.9
AVERAGE LOW	34.2
MONTHLY MEAN	47.6
DAYS WITH HIGH 90 OR ABOVE	0 (* Less than one)
DAYS WITH HIGH 32 OR BELOW	0 (* Less than one)
DAYS WITH LOW 32 OR BELOW	11
DAYS WITH LOWS ZERO OR BELOW	0 (* Less than one)
PRECIPITATION
MONTHLY MEAN	1.93 INCHES
DAYS WITH MEASURABLE PRECIPITATION	9
AVERAGE SNOWFALL	9.1 INCHES (3rd SNOWIEST MONTH)
DAYS WITH 1.0 INCH OR MORE SNOWFALL	3
MISCELLANEOUS APRIL AVERAGES
HEATING DEGREE DAYS	524
COOLING DEGREES DAYS	2
WIND SPEED (MPH)	10.0
WIND DIRECTION	SOUTH
DAYS WITH THUNDERSTORMS	2
DAYS WITH DENSE FOG	1
PERCENT OF SUNSHINE POSSIBLE	67
APRIL EXTREMES
RECORD HIGH	90 ON APRIL 30, 1992
RECORD LOW	-2 ON APRIL 2, 1975
WARMEST	56.4 DEGREES IN 1946 AND 1981
COLDEST	38.8 DEGREES IN 1920
WETTEST	8.24 INCHES IN 1900
MAXIMUM 24 HOUR MOISTURE	3.25 INCHES ON THE 13TH IN 1967
DRIEST	0.03 INCH IN 1963
SNOWIEST	33.8 INCHES IN 1933
MAXIMUM 24 HOUR SNOWFALL	23.0 INCHES ON 22-23 IN 1885
LEAST SNOWIEST	0.0 INCHES IN 1888, 1930, 1943, 1992; THERE WERE 8 YEARS WITH TRACE AMOUNTS

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