Thornton, Colorado, USA
UpdatedFri, 28-Oct-2016 9:50am MDT 


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Japan, Taiwain, Hong Kong In Path Of Monster Tropical Cyclone

Tuesday, September 13th, 2016 12:15pm MDT

Taiwan and mainland China were in the path of a monster tropical cyclone Tuesday night that was expected to bring heavy rains and gusts of up to 225 mph. The massive Super Typhoon Meranti grew from a Category 1 equivalent storm to a top-scale Category 5 seemingly overnight, bringing winds of 185 mph barreling toward the… » Click here to read the rest of Japan, Taiwain, Hong Kong In Path Of Monster Tropical Cyclone

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Thornton’s Tuesday brings a taste of fall

Tuesday, September 13th, 2016 5:01am MDT

The official start to autumn is still more than a week away but that close proximity will be felt in our weather today. Overcast skies, cool temperatures and damp conditions will definitely make us aware the change in seasons is coming.

Overnight last night we received 0.03 inches of precipitation. Not much at all but enough to dampen things up. Throughout the day today we do stand a slight chance for some more sprinkles or light showers although it won’t be amounting to much if any.

Overhead we will have a healthy dose of cloud cover with just a bit of a break by late morning into the afternoon. Temperatures will be topping out in the mid to upper 60s, well below the 80 degree average for the date.

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North Korea Floods Kill 133, Displace 107,000: U.N.

Monday, September 12th, 2016 10:18am MDT

More than 130 people have died and 107,000 have been forced to flee their homes in North Korea after flooding near the border with China and Russia, according to the United Nations. Flooding of the Tumen River in the country’s northeast has killed 133 people and left 395 missing, said a U.N. statement dated Sunday, AFP… » Click here to read the rest of North Korea Floods Kill 133, Displace 107,000: U.N.

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Cold front to bring cooler temps, breezy winds

Monday, September 12th, 2016 5:19am MDT

A cold front is working its way into the state and as it does, we will see some notable changes to our weather. Temperatures will be a good bit cooler today and we also will get a dose of wind and a slight chance for storms.

We start out the day with mostly sunny skies. By mid-morning we will start to see a bit of an increase in cloud cover with partly sunny skies above in the afternoon and evening.

Temperatures today are going to be topping out in the mid-70s, far below yesterday’s 90 degree reading and a good way below the average of 80 degrees for the date.

As the front pushes through we are going to see an increase in winds that will last much of the day. Gusts to 25mph or so will be seen. From about noon onward we will have a slight chance for showers and thunderstorms as the atmosphere destabilizes a bit.

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September 11 to September 17: This Week in Denver Weather History

Sunday, September 11th, 2016 1:03pm MDT
This Week In Denver Weather History

September 11 to September 17: This Week in Denver Weather History

Severe weather is less common as we enter the fall season but it is not entirely unheard of. As we see in our look back at this week in Denver weather history, we have seen everything ranging from torrential rains to tornadoes and even heavy snow.


In 1910…west winds were sustained to 42 mph.

In 1951…a vigorous Canadian cold front produced a dust storm across metro Denver. Northeast wind gusts to 43 mph reduced the visibility at Stapleton Airport to as low as 1 1/2 miles for nearly 5 hours. The temperature dropped 47 degrees in 8 hours…from a high of 92 degrees to a low of 45 degrees.

In 1967…a microburst wind gust to 52 mph produced blowing dust and briefly reduced the visibility to 1/2 mile at Stapleton International Airport.

In 1974…a trace of snow…the first of the season…ended the shortest period without snow…94 days from June 9th through September 10th. A trace of snow also fell on June 8th.

In 1995…strong post-frontal winds associated with a fast moving pacific cold front knocked down power poles and trees as it moved through metro Denver. Numerous power outages affected nearly one thousand people in Denver and Jefferson counties. West winds gusted to 34 mph at Denver International Airport.


In 2013…a deep southerly flow over Colorado… Ahead of a nearly stationary low pressure system over the great basin… Pumped copious amounts of monsoonal moisture into the area. In addition…a weak stationary front stretched along the Front Range foothills and Palmer Divide.  This resulted in a prolonged period of moderate to heavy rain across the Front Range foothills…Palmer Divide…urban corridor. By the 14th…storm totals ranged from 6 to 18 inches… Highest in the foothills of Boulder County. The headwaters then moved down the South Platte River and caused widespread flooding with record flood stages at several locations as it made its way downstream.  The record high flood stages resulted in widespread flooding along the South Platte River basin. The flood damage encompassed 4500 square miles of the Front Range…left 7 dead… Forced thousands to evacuate…and destroyed thousands of homes and farms. Record amounts of rainfall generated flash floods that tore up roads and lines of communication… Leaving many stranded. Nearly 19000 homes were damaged… And over 1500 destroyed. Colorado department of transportation estimated at least 30 state highway bridges were destroyed and an additional 20 seriously damaged. Preliminary assessments of the state`s infrastructure showed damage of $40 million to roads and $112 million to bridges. Repair costs for state and county roads ran into the hundreds of millions of dollars. Miles of freight and passenger rail lines were washed out or submerged… Including a section servicing Amtrak`s iconic California Zephyr. The town of Lyons was isolated by the flooding of St. Vrain creek…and several earth dams along the Front Range burst or were over-topped. Floodwaters swept through Estes Park; damaged hundreds of buildings and destroyed large sections of U.S. 34 from Loveland and U.S. 36 from Lyons to Boulder. U.S. 34 suffered the most damage… With 85 percent of its roadway and bridges destroyed. In Weld County…about nearly two thousand gas wells were damaged and had to be closed off as the floodwaters inundated entire communities. Sewage treatment plants and other utilities were knocked out in a number of towns. Governor Hickenlooper declared a disaster emergency on September 13th…in 11 counties across northeast Colorado including:  Adams…Arapahoe…Broomfield…Boulder…Denver…  Jefferson…Larimer…Logan…Morgan… Washington and Weld. By the 15th…federal emergency declarations covered those counties as well as Clear Creek County. Projected losses from the flooding statewide was nearly two billion dollars in property damage…according to Eqecat… A catastrophe modeling firm.  The damage was most severe in and around Lyons and Boulder.  More than 11 thousand people were evacuated…reportedly the largest since Hurricane Katrina. President Obama declared a state of emergency for Boulder and Larimer counties.  An additional 10 counties were added on the 16th and included: Adams… Arapahoe…Broomfield…Clear Creek…Denver…Jefferson…  Morgan…Logan… Washington and Weld counties. The president also declared a major disaster specifically for Boulder County.  There were six fatalities directly attributed to flash flooding. Two 19-yr old teenagers died on the 11th…after they were swept away by floodwaters after abandoning their car on Lindon Drive in Boulder. In Jamestown…a 72-yr old man was killed when the building he was in collapsed. An 80-yr old Lyons resident died in the early morning hours of the 12th…when his truck was swept into the St. Vrain River near his home. Later on the 12th…a 79-yr old Larimer County resident was killed when she was swept away while trying to climb to safety from her home in Cedar Point. A 61-yr old cedar point resident died when her home was swept down the Big Thompson River by the floodwaters. An 80-yr old Idaho Springs resident drowned in Clear Creek when the embankment he was standing on collapsed. In Boulder…some of the monthly records broken included: one-day all-time record: 9.08 inches which shattered the previous wettest day of 4.8 inches set on July 31… 1919; one-month record of 18.16 inches…which broke the previous all-time monthly record of 9.59 inches set in May of 1995; wettest September on record which broke the previous record of 5.5 inches set in September of 1940; one-year record of 34.15 inches broke the previous wettest year of 29.93 inches set in 1995. At Denver International Airport…the total precipitation for the month of September was 5.61 inches…which was 4.65 inches above the normal of 0.96 inches. This is the most precipitation ever recorded in Denver for the month of September. Daily precipitation records included 1.11 inches on the 12th and 2.01 inches on the 14th.


In 1974…post-frontal rain changed to snow overnight for the first snow of the season. Snowfall totaled only 1.8 inches at Stapleton International Airport where north winds gusted to 40 mph on the 11th. High temperature of only 46 degrees on the 12th set a new record low maximum for the date.

» Click here to read the rest of September 11 to September 17: This Week in Denver Weather History

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Thornton’s weekend to be dry, start cooler then heat back up

Friday, September 9th, 2016 5:19am MDT

The three-day period is going to feature varying temperatures from comfortable and seasonal to hot by the time it ends. Overall conditions will be dry and calm.

A cold front will be moving through on Friday and that is going to cool things down over the mercury readings of recent days. Look for a high temperature around the 80 degree mark. We’ll see sunny skies above and dry conditions. Some breezy winds can be expected by mid-afternoon into the evening.

For Saturday, weather conditions look to be fantastic for the city’s annual Harvest Fest. Conditions will be much like today with highs just a hair below normal and lots of sun and calm conditions.

The heat returns to close out the weekend as high pressure returns. High temperatures on Sunday, Patriot Day, will be pushing at and perhaps a bit above 90 degrees. It will be sunny and dry.

Have a great weekend!

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Thornton’s Thursday brings unseasonably warm temps, dry conditions

Thursday, September 8th, 2016 5:09am MDT

Our weather today will offer up mercury readings a good bit above normal. With drier air in place, there will be less cloud cover than yesterday and conditions will be calm.

We start out the day with sunny skies that will last until about noon. After that a few high clouds will arrive but nothing that will be obtrusive. Temperatures will be climbing to a high in the mid to upper 80s. Average for today’s date is 82 degrees.

All-in-all, a decent late summer day.

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Warmer temps, some cloud cover for Thornton’s Wednesday

Wednesday, September 7th, 2016 5:16am MDT

The remnants of Hurricane Newton which struck Baja California yesterday morning will begin to make itself felt all the way here in Colorado today. Moisture from the storm will be pushing our way although for us it only means clouds versus precipitation.

We start out this morning with a healthy layer of clouds and some spots with patchy fog. By mid-morning we should start to see that burn off although high clouds will be present throughout the day.

Temperatures today will be topping out in the mid-80s, a few degrees above normal. We expect to remain dry with not storms in our area.

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August 2016 weather recap: Thornton enjoys cooler than normal temps but little precip

Tuesday, September 6th, 2016 7:49am MDT

Our August weather was a bit of a mixed bag by the two biggest standards.  On one hand, it was cooler than normal which was nice.  On the other, we saw less than half the amount of precipitation we normally see during August.

August typically is when the monsoon kicks in and we see healthy doses of precipitation.  This year however, the monsoonal flow was regularly disrupted by troughs digging in from the north and west.

  • August 2016 top shots: Monthly photo slideshow

We certainly started the month hot with three days of temperatures near or above 95 degrees.  Things then cooled down for a few days as the first trough moved through.  Warmer temperatures then returned with readings not too far off of normal for the next two weeks.  The final 10 days or so of the month then saw cooler conditions with the majority of days recording readings below normal.

Thornton’s overall average temperature for the month came in at 69.5 degrees.  That was three degrees cooler than Denver’s long term average of 72.5 degrees.  Out at the airport where Denver’s official measurements are taken, the airport split the difference with an average of 71.2 degrees.

Temperature ranged from a high of 97.2 degrees on the third of the month down to a cool 46.7 degrees on the 25th.  Denver saw a maximum of 97 degrees on the 9th and a low of 47 degrees on the 25th.  Thornton saw 14 days with highs at or above 90 degrees while Denver recorded 15.

Officially, one temperature record was made.  On the morning of the 27th the mercury at DIA dropped to 48 degrees typing the record low for the date.

In terms of precipitation, Denver averages 1.69 inches during the month of August.  Thornton saw only 0.76 inches in our rain bucket.  The airport fared even worse with only 0.22 inches making the month the eight driest August on record in Denver.

Click here to view Thornton’s August 2016 climate report.

Thornton, Colorado's August 2016 temperature summary. (ThorntonWeather.com)

Thornton, Colorado’s August 2016 temperature summary. (ThorntonWeather.com)

Thornton, Colorado's August 2016 precipitation summary. (ThorntonWeather.com)

Thornton, Colorado’s August 2016 precipitation summary. (ThorntonWeather.com)

From the National Weather Service:

848 AM MDT THU SEP 1 2016




                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
 HIGH             105   08/08/1878
 LOW               40   08/26/1910
HIGHEST            97   08/09                         98  08/15
LOWEST             47   08/25                         43  08/23
AVG. MAXIMUM     86.3              87.2    -0.9     89.8
AVG. MINIMUM     56.2              57.9    -1.7     58.3
MEAN             71.2              72.5    -1.3     74.0
DAYS MAX >= 90     15              11.5     3.5       19
DAYS MAX <= 32      0               0.0     0.0        0
DAYS MIN <= 32      0               0.0     0.0        0
DAYS MIN <= 0       0               0.0     0.0        0

 MAXIMUM         5.85   1979
 MINIMUM         0.02   1924
TOTALS           0.22              1.69   -1.47     1.18
DAILY AVG.       0.01              0.05   -0.04     0.04
DAYS >= .01         4               8.6    -4.6        9
DAYS >= .10         1               4.3    -3.3        4
DAYS >= .50         0               1.2    -1.2        1
DAYS >= 1.00        0               0.3    -0.3        0
 24 HR. TOTAL    0.12   08/24 TO 08/24           08/11 TO 08/11
                                                          08/10 TO 08/11

HEATING TOTAL      15                10       5       13
 SINCE 7/1         15                16      -1       18
COOLING TOTAL     218               244     -26      304
 SINCE 1/1        762               688      74      713

 EARLIEST     09/08/1962
 LATEST       06/08/2007
EARLIEST                        10/07
LATEST                          05/05

AVERAGE WIND SPEED              9.9

AVERAGE SKY COVER           0.60
NUMBER OF DAYS FAIR            4
NUMBER OF DAYS PC             22


THUNDERSTORM             11     MIXED PRECIP               0
HEAVY RAIN                0     RAIN                       1
LIGHT RAIN               10     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                0     SLEET                      0
FOG                       5     FOG W/VIS <= 1/4 MILE      3
HAZE                      4

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September preview: The end of summer brings one of our most pleasant months

Tuesday, September 6th, 2016 6:54am MDT

Following on what was a cool but dry August, some are certainly hoping for a bit of precipitation.  The month can bring plenty of rain and even our first snow of the season but more often than not, it is one of the most pleasant along the Colorado Front Range.

As temperatures start to drop, September usually reminds us that summer is at an end and fall is now here. Sunshine is predominant though as the month actually has the highest percentage of sun out of any month. Sunny days and clear, cool nights are the standard weather pattern for the month.

The month can bring extremes however.  We will of course forever remember last year’s devastating floods brought on by record-setting rain.  Longtime residents might remember September 1971 which brought over 17 inches of snowfall.

Get a complete look at September’s weather and more details as to what we can expect this year here.

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