Updated Through Halloween 2006
National Weather Service, Boulder, CO
There seems to be a popular belief in Denver that it almost always snows on the day that the goblins and ghosts head through the neighborhoods seeking sweet delights.
Let's take a quick look through 51 years of weather statistics (1954-2005) for Denver to see if in fact that snow actually plays a role on Halloween.
If you examine only October 31st...Snow has only fallen 10 times during the past 52 years of which 8 of the days had measurable snowfall. This works out to be about once every 5 years. However...if you include the days that had snow on the ground on October 31st but no snow actually fell during the trick or treat times (5pm - 8pm), you can add in an additional 11 times. Then...to this total....if you include the number of times snow fell on November 1st, which increases the total by 20, which will now bring the grand total of snow days associated with the period October 31 through November 1st to 41 times. Since this total equates to approximately 79 percent of the time during the 52 year period...it is no wonder that people think of snow when Halloween is discussed in Denver.
Snow was definitely upon us on the old witches and ghosts evening during 2004. Depending on where you were...snowfall amounts around northeast Colorado ranged from 0.3 inches at Greeley up to 14.5 inches at Aspen Park. The Denver International Airport reported 1.4 inches. As forecast...the area started off with rain around 6pm which then quickly changed to snow. By 8pm...only snow was falling. Here are some of the snowfall reports from around the Denver metro area: Bailey 7.0 inches... Larkspur 6.5 inches...Evergreen 5.0 inches... Aurora 4.3 inches...Chatfield Reservoir 6.9 inches...Thornton 2.8 inches... Lafayette 1.5 inches...Sedalia 10.0 inches...Jamestown 6.5 inches...Boulder 2.8 inches...Morrison 5.5 inches... Englewood 5.0 inches...Denver 3.7 inches...Castle Rock 6.8 inches and Centennial recorded 8.0 inches.
During Halloween...2003...drizzle...light rain and freezing drizzle accompanied the ghosts and goblins. Some very light snow did occur across parts of the metro area but not at Stapleton International or Denver International. Average temperature during trick or treat time was 27.5 degrees.
During Halloween 2002...mother nature turned on the winter machine and the trick-or-treaters marched through some snow as they collected their sweet goodies. At Stapleton Airport...1.2 inches of snow was recorded on Halloween with an average snow depth of 2 inches. This was only the 7th occurrence of snow in Denver on October 31st since 1954. Temperatures for the kiddos during trick-or-treat time was in the mid to upper teens. Snowfall was also recorded on the day before Halloween...2.2 inches and again on November 1st...0.6 inch.
Previous to 2002...the last measurable snow occurred in 1989. There was a mixture of rain and snow early in the day before changing to all snow late in the day. A total of 3.4 inches of snow fell with another 1.1 inches on November 1st. In 1992...nearly half of an inch of liquid precipitation... 0.42 inch...fell but no snow was recorded because during the time period of the rain... Temperatures were just above the snow temperature threshold.
Mother Nature played a real trick on the Denver treaters for Halloween in 1972. The high on that particular jack-o-lantern day was only 30 degrees and the low bottomed out at a very cold 15 degrees. Eight inches of snow was recorded on October 31st and to top that off... An additional 5.8 inches of snow fell on November 1st.
During the past 49 years...the average temperature during the time most kids are out (5pm-8pm) is 42.5 degrees. The coldest trick-or-treat period was in 2002...with an average temperature of only 18 degrees. The warmest trick-or-treat time was in 1990 with an average temperature of 63 degrees. The average high temperature for the last day of October is 55.7 degrees while the average low temperature is 30.2 degrees. Note: the temperature normally drops about 8 degrees from sunset until the time that the kiddos are collecting their treats.
In 1999...Halloween day turned out to be the warmest October since we started keeping these Halloween statistics in 1954. But during the 5pm to 8pm time frame...1990 actually had a warmer average temperature with a 63 degree average. In 1999...the average trick or treat temperature was a very pleasant 59 degrees. That was 23 degrees warmer than the average temperature during 1998 when the mercury averaged only 36 degrees.
"Denver's Halloween Weather Statistics"
Halloween Summary and Averages (To include Max and Min Values)
Number of
Years = 53 |
High |
Low |
Precip
10/31 |
Snowfall
10/31 |
Snow Depth
At 5PM |
|
AvgTemp
5PM-8PM
|
10/31&11/01
Snow Totals |
Max Value |
77
|
47
|
0.53
|
8.0
|
4.0
|
5.8
|
63
|
|
|
| Min Value |
19 |
10 |
0.00 |
0.0 |
0 |
0.0 |
18 |
|
|
|
|
|
|
|
|
|
|
Total Days
Measurable |
|
|
15 |
8 |
6 |
11 |
|
19 |
|
|
|
|
|
|
|
|
|
Total Days
Trace Only |
|
|
5 |
2 |
4 |
8 |
|
10 |
|
|
|
|
|
|
|
|
|
| Average or Total |
55.3 |
29.9 |
20 |
10 |
10 |
19 |
42.3 |
29 |
|
|
|
|
|
|
|
|
|
| Percent |
|
|
37.7% |
18.9% |
18.9% |
35.8%
|
|
54.7% |
Year |
High |
Low |
Precip |
Snowfall
Oct 31st |
Snow Depth
At 5PM |
Avg Temp
5PM-8PM |
Snowfall
Nov 1st |
2006 |
38 |
23 |
0 |
0 |
0 |
30 |
0 |
2005 |
55 |
31 |
0 |
0 |
0 |
45 |
0 |
2004 |
55 |
24 |
0.27 |
1.4 |
0 |
39 |
1.8 |
2003 |
30 |
23 |
0.07 |
0.0 |
0 |
28 |
0.0 |
2002 |
19 |
15 |
0.03 |
1.2 |
2 |
18 |
0.6 |
2001 |
71 |
37 |
0 |
0 |
0 |
54 |
0 |
2000 |
46 |
33 |
0.07 |
0 |
0 |
43 |
0 |
1999 |
77 |
31 |
0 |
0 |
0 |
59 |
0 |
1998 |
38 |
34 |
0.06 |
0 |
0 |
36 |
T |
1997 |
59 |
38 |
T |
0 |
0 |
41 |
0 |
1996 |
32 |
28 |
T |
T |
0 |
30 |
0.1 |
1995 |
45 |
27 |
0 |
0 |
0 |
35 |
0.9 |
1994 |
59 |
27 |
0 |
0 |
0 |
53 |
0 |
1993 |
65 |
27 |
0 |
0 |
1 |
46 |
0.5 |
1992 |
53 |
35 |
0.42 |
0 |
0 |
40 |
0 |
1991 |
32 |
10 |
0 |
0 |
3 |
24 |
2.3 |
1990 |
72 |
37 |
0 |
0 |
0 |
63 |
0 |
1989 |
59 |
24 |
0.24 |
3.4 |
0 |
36 |
1.1 |
1988 |
73 |
34 |
0 |
0 |
0 |
58 |
0 |
1987 |
62 |
47 |
0 |
0 |
0 |
54 |
0 |
1986 |
44 |
33 |
0.51 |
1.2 |
0 |
37 |
2.8 |
1985 |
59 |
36 |
0.38 |
0 |
0 |
39 |
0 |
1984 |
67 |
24 |
0 |
0 |
0 |
50 |
0 |
1983 |
71 |
41 |
T |
0 |
0 |
58 |
0 |
1982 |
53 |
34 |
0.04 |
0 |
0 |
46 |
0 |
1981 |
53 |
36 |
0 |
0 |
0 |
46 |
0 |
1980 |
76 |
36 |
0 |
0 |
0 |
58 |
0 |
1979 |
40 |
23 |
0 |
0 |
T |
32 |
T |
1978 |
59 |
32 |
0 |
0 |
0 |
46 |
0 |
1977 |
56 |
28 |
0.39 |
3.3 |
0 |
34 |
0 |
1976 |
61 |
31 |
0 |
0 |
T |
48 |
T |
1975 |
55 |
37 |
T |
0 |
0 |
48 |
0 |
1974 |
56 |
28 |
0 |
0 |
0 |
45 |
0 |
1973 |
62 |
38 |
0 |
0 |
0 |
39 |
0.8 |
1972 |
30 |
15 |
0.53 |
8.0 |
2 |
28 |
5.8 |
1971 |
53 |
21 |
0 |
0 |
0 |
40 |
T |
1970 |
54 |
24 |
0 |
0 |
T |
34 |
T |
1969 |
45 |
24 |
0 |
0 |
T |
36 |
2.7 |
1968 |
63 |
37 |
0.23 |
0 |
0 |
44 |
0 |
1967 |
63 |
33 |
0 |
0 |
0 |
50 |
0 |
1966 |
48 |
26 |
0.16 |
1.4 |
0 |
32 |
0 |
1965 |
66 |
29 |
0 |
0 |
0 |
47 |
0 |
1964 |
66 |
35 |
0 |
0 |
0 |
46 |
0 |
1963 |
45 |
27 |
0.16 |
1.1 |
0 |
36 |
0 |
1962 |
71 |
31 |
0 |
0 |
0 |
41 |
0 |
1961 |
56 |
29 |
0 |
0 |
1 |
48 |
T |
1960 |
61 |
34 |
0 |
0 |
0 |
53 |
0 |
1959 |
48 |
21 |
0 |
0 |
4 |
36 |
T |
1958 |
52 |
28 |
0 |
0 |
0 |
37 |
0 |
1957 |
70 |
39 |
0 |
0 |
0 |
54 |
0 |
1956 |
65 |
32 |
0 |
0 |
0 |
56 |
4.7 |
1955 |
65 |
35 |
T |
T |
0 |
38 |
T |
1954 |
58 |
24 |
0 |
0 |
0 |
26 |
0 |
|