Record envelope, standing records and threshold days for Gillette 18 SW (USC00483865), Wyoming, United States, with 37 years of record.
Key Facts for Gillette 18 SW
Gillette 18 SW (USC00483865) is a weather station in Wyoming, United States at 44.08 latitude and -105.72 longitude, 1,495 m (4,905 ft) above sea level.
The station reports from 1949 to 1985, 37 years of record.
1,464 records set at Gillette 18 SW still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Gillette 18 SW set a monthly record low minimum temperature of -8.9 C (16.0 F) on 30 September 1985.
About the Station
Location: Wyoming, United States, 44.08 latitude, -105.72 longitude.
Elevation: 1,495 m (4,905 ft).
Period of record: 1949 to 1985, 37 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
0 days at or beyond a record
Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at Gillette 18 SW. The lines show the 2026 daily maximum and minimum. 0 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Gillette 18 SW, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
18.3 C (64.9 F)
-35.6 C (-32.1 F)
n/a
n/a
Feb
21.1 C (70.0 F)
-34.4 C (-29.9 F)
n/a
n/a
Mar
23.9 C (75.0 F)
-30.6 C (-23.1 F)
n/a
n/a
Apr
28.9 C (84.0 F)
-17.8 C (0.0 F)
n/a
n/a
May
32.8 C (91.0 F)
-11.1 C (12.0 F)
n/a
n/a
Jun
39.4 C (102.9 F)
-2.8 C (27.0 F)
n/a
n/a
Jul
40.0 C (104.0 F)
1.7 C (35.1 F)
n/a
n/a
Aug
38.3 C (100.9 F)
-1.1 C (30.0 F)
n/a
n/a
Sep
37.2 C (99.0 F)
-8.9 C (16.0 F)
n/a
n/a
Oct
30.6 C (87.1 F)
-23.9 C (-11.0 F)
n/a
n/a
Nov
23.3 C (73.9 F)
-32.2 C (-26.0 F)
n/a
n/a
Dec
17.8 C (64.0 F)
-38.9 C (-38.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Gillette 18 SW still stand. 1954 holds the most, with 68.
Standing records at Gillette 18 SW by the year they were set
Year set
Standing records
1949
19
1950
55
1951
53
1952
43
1953
48
1954
68
1955
47
1956
48
1957
40
1958
43
1959
46
1960
43
1961
35
1962
51
1963
45
1964
27
1965
43
1966
52
1967
29
1968
40
1969
48
1970
24
1971
30
1972
53
1973
51
1974
24
1975
39
1976
24
1977
27
1978
34
1979
25
1980
43
1981
28
1982
21
1983
61
1984
27
1985
30
All-Time Record Progression
3 new records
3 all-time records were set at Gillette 18 SW between 6 July 1981 and 24 December 1983. Each dot is a new record.
When Gillette 18 SW set new all-time records
Date
Kind
Detail
1981-07-06
Record high maximum temperature
Record high maximum temperature 40.0 C (104.0 F)
1982-07-22
Record high minimum temperature
Record high minimum temperature 23.9 C (75.0 F)
1983-12-24
Record low minimum temperature
Record low minimum temperature -38.9 C (-38.0 F)
Wettest Day of Each Month
May: 67.3 mm (2.6 in)
The wettest day on record for each calendar month at Gillette 18 SW. The most was 67.3 mm (2.6 in) on 18 May 1978.
Record daily precipitation for each month at Gillette 18 SW
Month
Record daily precipitation (mm)
Date
Jan
22.4 mm (0.9 in)
14 January 1953
Feb
20.3 mm (0.8 in)
22 February 1977
Mar
21.6 mm (0.9 in)
3 March 1985
Apr
49.5 mm (1.9 in)
25 April 1969
May
67.3 mm (2.6 in)
18 May 1978
Jun
64.8 mm (2.6 in)
3 June 1963
Jul
53.3 mm (2.1 in)
25 July 1981
Aug
66.0 mm (2.6 in)
17 August 1960
Sep
36.3 mm (1.4 in)
14 September 1982
Oct
42.2 mm (1.7 in)
2 October 1971
Nov
25.4 mm (1.0 in)
3 November 1956
Dec
15.5 mm (0.6 in)
2 December 1982
Period of Record Coverage
1949 to 1985
Complete yearUnder 90 percent of days
37 years of record at Gillette 18 SW, 1949 to 1985. 2 years have data for under 90 percent of days and are left out of rankings: 1949, 1985.
Cooler than the station meanWarmer than the station mean
One stripe for each of 32 complete years at Gillette 18 SW, 1950 to 1984. Blue stripes are years cooler than the station's own mean of 6.7 C (44.1 F); red stripes are warmer. The coolest year was 1951, at 5.0 C (41.0 F), and the warmest was 1954, at 8.0 C (46.4 F). The strongest colour marks a difference of 1.8 C (3.2 F).
Annual mean temperature at Gillette 18 SW as warming stripes, 1950 to 1984
Year
Annual mean temperature
Difference from the station mean
1950
5.7 C
-1.02 C
1951
5.0 C
-1.71 C
1952
7.3 C
+0.59 C
1953
7.7 C
+0.98 C
1954
8.0 C
+1.31 C
1955
6.1 C
-0.63 C
1956
7.3 C
+0.54 C
1957
6.6 C
-0.11 C
1958
7.3 C
+0.58 C
1959
6.6 C
-0.14 C
1960
7.1 C
+0.36 C
1961
7.1 C
+0.36 C
1962
6.8 C
+0.11 C
1963
7.7 C
+0.97 C
1964
5.9 C
-0.83 C
1965
6.4 C
-0.35 C
1966
7.2 C
+0.45 C
1967
6.5 C
-0.19 C
1968
6.5 C
-0.23 C
1969
7.0 C
+0.26 C
1970
6.5 C
-0.20 C
1971
6.2 C
-0.48 C
1972
6.4 C
-0.31 C
1973
7.1 C
+0.39 C
1975
6.4 C
-0.32 C
1976
7.2 C
+0.51 C
1977
6.9 C
+0.19 C
1978
5.4 C
-1.31 C
1980
7.6 C
+0.89 C
1982
5.8 C
-0.87 C
1983
7.0 C
+0.33 C
1984
6.7 C
-0.06 C
The fitted trend in annual mean temperature here over 1950 to 1984 is -0.04 C (-0.29 to 0.22) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.1 F (-0.5 to 0.4) per decade. The slope is a straight line fitted to 32 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Gillette 18 SW
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.04 C (-0.29 to 0.22) per decade
-0.1 F (-0.5 to 0.4) per decade
1950 to 1984
32
Not clearly different from zero
Mean daily maximum
-0.1 C (-0.4 to 0.2) per decade
-0.1 F (-0.7 to 0.4) per decade
1950 to 1984
32
Not clearly different from zero
Mean daily minimum
0.00 C (-0.23 to 0.23) per decade
-0.01 F (-0.42 to 0.41) per decade
1950 to 1984
32
Not clearly different from zero
A year is complete when all 12 months have at least 20 days of both daily maximum and daily minimum readings. The annual mean is the mean of the monthly means. The trend describes this one station over this period; it does not say what caused the change.
Extremes by Year
1949 to 1985
Yearly extremes at Gillette 18 SW: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
40.0 C (104.0 F)
1981
36.7 C (98.1 F)
37
Coldest night (TNn)
-38.9 C (-38.0 F)
1983
-31.7 C (-25.1 F)
37
Wettest day (Rx1day)
67.3 mm (2.6 in)
1978
38.1 mm (1.5 in)
37
Wettest five days (Rx5day)
132.6 mm (5.2 in)
1978
56.4 mm (2.2 in)
37
Longest dry spell (CDD)
69 days
1952
29 days
37
Hottest day (TXx)
The hottest day of the year at Gillette 18 SW, 1949 to 1985. The record is 40.0 C (104.0 F) in 1981, marked on the chart; the median year is 36.7 C (98.1 F).
Hottest day (TXx) at Gillette 18 SW by year
Year
Hottest day (TXx)
1949
36.7 C (98.1 F)
1950
33.9 C (93.0 F)
1951
36.7 C (98.1 F)
1952
38.3 C (100.9 F)
1953
37.2 C (99.0 F)
1954
39.4 C (102.9 F)
1955
36.7 C (98.1 F)
1956
36.7 C (98.1 F)
1957
38.3 C (100.9 F)
1958
35.6 C (96.1 F)
1959
36.7 C (98.1 F)
1960
36.7 C (98.1 F)
1961
37.2 C (99.0 F)
1962
34.4 C (93.9 F)
1963
35.0 C (95.0 F)
1964
35.0 C (95.0 F)
1965
36.1 C (97.0 F)
1966
38.9 C (102.0 F)
1967
35.0 C (95.0 F)
1968
35.0 C (95.0 F)
1969
36.7 C (98.1 F)
1970
36.1 C (97.0 F)
1971
36.1 C (97.0 F)
1972
38.3 C (100.9 F)
1973
38.3 C (100.9 F)
1974
37.2 C (99.0 F)
1975
37.8 C (100.0 F)
1976
37.2 C (99.0 F)
1977
38.3 C (100.9 F)
1978
37.2 C (99.0 F)
1979
38.3 C (100.9 F)
1980
36.7 C (98.1 F)
1981
40.0 C (104.0 F)
1982
35.0 C (95.0 F)
1983
38.3 C (100.9 F)
1984
36.7 C (98.1 F)
1985
36.7 C (98.1 F)
Coldest night (TNn)
The coldest night of the year at Gillette 18 SW, 1949 to 1985. The record is -38.9 C (-38.0 F) in 1983, marked on the chart; the median year is -31.7 C (-25.1 F).
Coldest night (TNn) at Gillette 18 SW by year
Year
Coldest night (TNn)
1949
-23.3 C (-9.9 F)
1950
-32.2 C (-26.0 F)
1951
-35.6 C (-32.1 F)
1952
-31.1 C (-24.0 F)
1953
-24.4 C (-11.9 F)
1954
-28.3 C (-18.9 F)
1955
-29.4 C (-20.9 F)
1956
-28.9 C (-20.0 F)
1957
-33.9 C (-29.0 F)
1958
-26.7 C (-16.1 F)
1959
-33.9 C (-29.0 F)
1960
-30.6 C (-23.1 F)
1961
-28.9 C (-20.0 F)
1962
-31.7 C (-25.1 F)
1963
-35.6 C (-32.1 F)
1964
-36.1 C (-33.0 F)
1965
-30.0 C (-22.0 F)
1966
-27.8 C (-18.0 F)
1967
-31.7 C (-25.1 F)
1968
-33.3 C (-27.9 F)
1969
-25.6 C (-14.1 F)
1970
-28.9 C (-20.0 F)
1971
-28.3 C (-18.9 F)
1972
-35.0 C (-31.0 F)
1973
-32.2 C (-26.0 F)
1974
-31.7 C (-25.1 F)
1975
-29.4 C (-20.9 F)
1976
-27.8 C (-18.0 F)
1977
-33.3 C (-27.9 F)
1978
-34.4 C (-29.9 F)
1979
-31.1 C (-24.0 F)
1980
-32.8 C (-27.0 F)
1981
-31.7 C (-25.1 F)
1982
-31.7 C (-25.1 F)
1983
-38.9 C (-38.0 F)
1984
-29.4 C (-20.9 F)
1985
-34.4 C (-29.9 F)
Wettest day (Rx1day)
The wettest day of the year at Gillette 18 SW, 1949 to 1985. The record is 67.3 mm (2.6 in) in 1978, marked on the chart; the median year is 38.1 mm (1.5 in).
Wettest day (Rx1day) at Gillette 18 SW by year
Year
Wettest day (Rx1day)
1949
12.7 mm (0.5 in)
1950
16.5 mm (0.6 in)
1951
30.0 mm (1.2 in)
1952
49.5 mm (1.9 in)
1953
40.1 mm (1.6 in)
1954
17.3 mm (0.7 in)
1955
36.8 mm (1.4 in)
1956
37.3 mm (1.5 in)
1957
30.5 mm (1.2 in)
1958
38.1 mm (1.5 in)
1959
38.6 mm (1.5 in)
1960
66.0 mm (2.6 in)
1961
22.9 mm (0.9 in)
1962
48.3 mm (1.9 in)
1963
64.8 mm (2.6 in)
1964
58.4 mm (2.3 in)
1965
25.9 mm (1.0 in)
1966
36.8 mm (1.4 in)
1967
47.0 mm (1.9 in)
1968
63.5 mm (2.5 in)
1969
49.5 mm (1.9 in)
1970
49.5 mm (1.9 in)
1971
42.2 mm (1.7 in)
1972
26.7 mm (1.1 in)
1973
38.1 mm (1.5 in)
1974
35.6 mm (1.4 in)
1975
28.2 mm (1.1 in)
1976
54.6 mm (2.1 in)
1977
20.3 mm (0.8 in)
1978
67.3 mm (2.6 in)
1979
61.5 mm (2.4 in)
1980
39.4 mm (1.6 in)
1981
53.3 mm (2.1 in)
1982
58.4 mm (2.3 in)
1983
28.7 mm (1.1 in)
1984
33.0 mm (1.3 in)
1985
21.6 mm (0.9 in)
Wettest five days (Rx5day)
The wettest five days of the year at Gillette 18 SW, 1949 to 1985. The record is 132.6 mm (5.2 in) in 1978, marked on the chart; the median year is 56.4 mm (2.2 in).
Wettest five days (Rx5day) at Gillette 18 SW by year
Year
Wettest five days (Rx5day)
1949
21.1 mm (0.8 in)
1950
35.3 mm (1.4 in)
1951
53.8 mm (2.1 in)
1952
81.8 mm (3.2 in)
1953
41.9 mm (1.6 in)
1954
26.5 mm (1.0 in)
1955
45.2 mm (1.8 in)
1956
56.4 mm (2.2 in)
1957
53.3 mm (2.1 in)
1958
78.3 mm (3.1 in)
1959
77.5 mm (3.1 in)
1960
66.0 mm (2.6 in)
1961
28.0 mm (1.1 in)
1962
83.8 mm (3.3 in)
1963
98.6 mm (3.9 in)
1964
107.7 mm (4.2 in)
1965
47.9 mm (1.9 in)
1966
37.3 mm (1.5 in)
1967
79.5 mm (3.1 in)
1968
63.5 mm (2.5 in)
1969
76.7 mm (3.0 in)
1970
57.3 mm (2.3 in)
1971
64.6 mm (2.5 in)
1972
37.1 mm (1.5 in)
1973
76.2 mm (3.0 in)
1974
45.0 mm (1.8 in)
1975
47.9 mm (1.9 in)
1976
66.2 mm (2.6 in)
1977
35.6 mm (1.4 in)
1978
132.6 mm (5.2 in)
1979
64.0 mm (2.5 in)
1980
48.3 mm (1.9 in)
1981
55.8 mm (2.2 in)
1982
68.0 mm (2.7 in)
1983
45.2 mm (1.8 in)
1984
83.9 mm (3.3 in)
1985
33.0 mm (1.3 in)
Longest dry spell (CDD)
The longest dry spell of the year at Gillette 18 SW, 1949 to 1985. The record is 69 days in 1952, marked on the chart; the median year is 29 days.
Longest dry spell (CDD) at Gillette 18 SW by year
Year
Longest dry spell (CDD)
1949
21 days
1950
32 days
1951
20 days
1952
69 days
1953
28 days
1954
31 days
1955
25 days
1956
29 days
1957
37 days
1958
29 days
1959
34 days
1960
29 days
1961
33 days
1962
39 days
1963
38 days
1964
31 days
1965
55 days
1966
21 days
1967
20 days
1968
22 days
1969
42 days
1970
36 days
1971
40 days
1972
20 days
1973
31 days
1974
24 days
1975
32 days
1976
29 days
1977
23 days
1978
29 days
1979
20 days
1980
23 days
1981
24 days
1982
18 days
1983
19 days
1984
38 days
1985
22 days
Each chart shows one value per year; the dot marks the record year. TXx is the hottest daily maximum, TNn the coldest daily minimum, Rx1day and Rx5day the largest one-day and five-day rain totals, and CDD the longest run of days with less than 1 mm of rain. A year with missing days can understate an extreme.
Frost Dates and Growing Season
32 years with a frost
Across 32 years with a frost, the median last spring frost at Gillette 18 SW falls on 27 May and the median first autumn frost on 15 September, which leaves a median of 113 days between them.
Fitted over all years, the growing season changes by 0.0 days per decade at this station.
Frost dates and growing season at Gillette 18 SW
Measure
Median, all years
Earliest period
Recent period (1952 to 1984)
Recent against earliest
Fitted trend
Last spring frost
27 May
n/a
25 May
n/a
+2.0 days per decade
First autumn frost
15 September
n/a
16 September
n/a
+2.0 days per decade
Growing days
113 days
n/a
116 days
n/a
0.0 days per decade
A frost day is a day with a daily minimum at or below 0 C (32 F). The last spring frost and the first autumn frost are the last and first such days of the cold season, and growing days are the days between them. A negative trend for the last spring frost means it comes earlier.
Rainfall Return Levels
35 years, 1950 to 1984
A day with at least 40.8 mm (1.6 in) of rain is expected about once in 2 years. A day with at least 78.2 mm (3.1 in) of rain is expected about once in 100 years.
Rainfall return levels at Gillette 18 SW: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
40.8 mm (1.6 in)
5 years
54.1 mm (2.1 in)
10 years
61.4 mm (2.4 in)
25 years
69.1 mm (2.7 in)
50 years
74.0 mm (2.9 in)
Longer than the 35 years of record
100 years
78.2 mm (3.1 in)
Longer than the 35 years of record
The levels come from a generalised extreme value (GEV) distribution fitted by L-moments to the wettest-day total of each year, 35 years of values from 1950 to 1984.
A return level is an estimate. It is least reliable for the long periods, 50 and 100 years, and for any period longer than the record behind the fit, where the fit has to reach past the largest day actually observed. It is not a forecast.
The largest wettest-day totals in the fit: 67.3 mm (2.6 in) in 1978; 66.0 mm (2.6 in) in 1960; 64.8 mm (2.6 in) in 1963.
Download the Data
Data for Gillette 18 SW standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Gillette 18 SW threshold days by year: CSV or JSON. Field meanings are on the data page.
Source: NOAA National Centers for Environmental Information, Global Historical Climatology Network Daily (GHCN-Daily). Records are computed by World Extreme Weather Monitor and are not official NOAA products. (US Government open data (NOAA NCEI)) Data as of 2026-10-16 (16 October 2026). Records are computed by this site and are not official.