Record envelope, standing records and threshold days for Bonanza (USC00420802), Utah, United States, with 56 years of record.
Key Facts for Bonanza
Bonanza (USC00420802) is a weather station in Utah, United States at 40.02 latitude and -109.18 longitude, 1,661 m (5,450 ft) above sea level.
The station reports from 1938 to 1993, 56 years of record.
1,464 records set at Bonanza still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Bonanza set a daily record precipitation of 5.6 mm (0.22 in) on 19 January 1993.
About the Station
Location: Utah, United States, 40.02 latitude, -109.18 longitude.
Elevation: 1,661 m (5,450 ft).
Period of record: 1938 to 1993, 56 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 Bonanza. 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 Bonanza, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
16.1 C (61.0 F)
-31.7 C (-25.1 F)
n/a
n/a
Feb
19.4 C (66.9 F)
-33.3 C (-27.9 F)
n/a
n/a
Mar
25.0 C (77.0 F)
-20.6 C (-5.1 F)
n/a
n/a
Apr
32.2 C (90.0 F)
-15.0 C (5.0 F)
n/a
n/a
May
34.4 C (93.9 F)
-7.2 C (19.0 F)
n/a
n/a
Jun
39.4 C (102.9 F)
-2.8 C (27.0 F)
n/a
n/a
Jul
41.1 C (106.0 F)
0.6 C (33.1 F)
n/a
n/a
Aug
41.1 C (106.0 F)
-2.2 C (28.0 F)
n/a
n/a
Sep
38.3 C (100.9 F)
-3.3 C (26.1 F)
n/a
n/a
Oct
31.7 C (89.1 F)
-18.3 C (-0.9 F)
n/a
n/a
Nov
25.0 C (77.0 F)
-20.6 C (-5.1 F)
n/a
n/a
Dec
16.1 C (61.0 F)
-35.6 C (-32.1 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Bonanza still stand. 1945 holds the most, with 54.
Standing records at Bonanza by the year they were set
Year set
Standing records
1938
14
1939
31
1940
40
1941
35
1942
25
1943
50
1944
23
1945
54
1946
20
1947
34
1948
53
1949
44
1950
41
1951
19
1952
29
1953
16
1954
35
1955
37
1956
20
1957
24
1958
30
1959
12
1960
6
1966
31
1967
26
1968
23
1969
22
1970
25
1971
41
1972
23
1973
19
1974
12
1975
35
1976
19
1977
42
1978
48
1979
23
1980
23
1981
30
1982
30
1983
27
1984
34
1985
33
1986
39
1987
16
1988
15
1989
32
1990
44
1991
34
1992
26
All-Time Record Progression
5 new records
5 all-time records were set at Bonanza between 7 July 1981 and 23 December 1990. Each dot is a new record.
When Bonanza set new all-time records
Date
Kind
Detail
1981-07-07
Record high maximum temperature
Record high maximum temperature 41.1 C (106.0 F)
1989-02-07
Record low minimum temperature
Record low minimum temperature -33.3 C (-27.9 F)
1990-12-22
Record low minimum temperature
Record low minimum temperature -34.4 C (-29.9 F)
1990-12-23
Record low maximum temperature
Record low maximum temperature -22.2 C (-8.0 F)
1990-12-23
Record low minimum temperature
Record low minimum temperature -35.6 C (-32.1 F)
Wettest Day of Each Month
Jun: 47.8 mm (1.9 in)
The wettest day on record for each calendar month at Bonanza. The most was 47.8 mm (1.9 in) on 11 June 1970.
Record daily precipitation for each month at Bonanza
Month
Record daily precipitation (mm)
Date
Jan
26.9 mm (1.1 in)
15 January 1941
Feb
20.3 mm (0.8 in)
20 February 1986
Mar
26.2 mm (1.0 in)
28 March 1979
Apr
25.9 mm (1.0 in)
1 April 1975
May
28.4 mm (1.1 in)
31 May 1985
Jun
47.8 mm (1.9 in)
11 June 1970
Jul
36.8 mm (1.4 in)
21 July 1985
Aug
25.9 mm (1.0 in)
11 August 1982
Sep
33.0 mm (1.3 in)
13 September 1958
Oct
36.8 mm (1.4 in)
24 October 1956
Nov
18.0 mm (0.7 in)
12 November 1978
Dec
31.2 mm (1.2 in)
6 December 1966
Period of Record Coverage
1938 to 1993
Complete yearUnder 90 percent of days
51 years of record at Bonanza, 1938 to 1993. 13 years have data for under 90 percent of days and are left out of rankings: 1938, 1960, 1966, 1967, 1968, 1969, 1970, 1971 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 31 complete years at Bonanza, 1939 to 1990. Blue stripes are years cooler than the station's own mean of 9.1 C (48.4 F); red stripes are warmer. The coolest year was 1984, at 7.1 C (44.8 F), and the warmest was 1981, at 10.8 C (51.4 F). The strongest colour marks a difference of 2.1 C (3.8 F).
Annual mean temperature at Bonanza as warming stripes, 1939 to 1990
Year
Annual mean temperature
Difference from the station mean
1939
8.7 C
-0.43 C
1940
9.3 C
+0.21 C
1941
7.8 C
-1.38 C
1942
8.3 C
-0.84 C
1943
10.1 C
+0.96 C
1945
9.8 C
+0.67 C
1946
10.5 C
+1.35 C
1947
9.7 C
+0.60 C
1948
9.1 C
-0.06 C
1949
8.6 C
-0.55 C
1950
9.1 C
-0.01 C
1953
10.1 C
+1.00 C
1954
10.7 C
+1.54 C
1956
9.5 C
+0.41 C
1957
9.1 C
-0.02 C
1958
10.3 C
+1.12 C
1967
8.5 C
-0.65 C
1969
9.0 C
-0.18 C
1970
8.6 C
-0.57 C
1975
8.4 C
-0.71 C
1976
9.5 C
+0.39 C
1977
10.5 C
+1.36 C
1978
8.4 C
-0.78 C
1979
7.7 C
-1.44 C
1980
9.6 C
+0.48 C
1981
10.8 C
+1.67 C
1982
8.5 C
-0.61 C
1983
9.1 C
-0.04 C
1984
7.1 C
-2.03 C
1989
8.5 C
-0.67 C
1990
8.2 C
-0.92 C
The fitted trend in annual mean temperature here over 1939 to 1990 is -0.1 C (-0.3 to 0.1) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.3 F (-0.6 to 0.1) per decade. The slope is a straight line fitted to 31 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Bonanza
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.1 C (-0.3 to 0.1) per decade
-0.3 F (-0.6 to 0.1) per decade
1939 to 1990
31
Not clearly different from zero
Mean daily maximum
-0.23 C (-0.50 to 0.05) per decade
-0.4 F (-0.9 to 0.1) per decade
1939 to 1990
31
Not clearly different from zero
Mean daily minimum
-0.1 C (-0.2 to 0.1) per decade
-0.1 F (-0.4 to 0.2) per decade
1939 to 1990
31
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
1938 to 1993
Yearly extremes at Bonanza: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
41.1 C (106.0 F)
1981
38.3 C (100.9 F)
51
Coldest night (TNn)
-35.6 C (-32.1 F)
1990
-25.6 C (-14.1 F)
51
Wettest day (Rx1day)
47.8 mm (1.9 in)
1970
20.8 mm (0.8 in)
51
Wettest five days (Rx5day)
80.6 mm (3.2 in)
1970
30.5 mm (1.2 in)
51
Longest dry spell (CDD)
104 days
1972
43 days
51
Hottest day (TXx)
The hottest day of the year at Bonanza, 1938 to 1993. The record is 41.1 C (106.0 F) in 1981, marked on the chart; the median year is 38.3 C (100.9 F).
Hottest day (TXx) at Bonanza by year
Year
Hottest day (TXx)
1938
37.8 C (100.0 F)
1939
38.9 C (102.0 F)
1940
39.4 C (102.9 F)
1941
37.2 C (99.0 F)
1942
37.2 C (99.0 F)
1943
40.6 C (105.1 F)
1944
36.1 C (97.0 F)
1945
38.3 C (100.9 F)
1946
37.2 C (99.0 F)
1947
39.4 C (102.9 F)
1948
37.8 C (100.0 F)
1949
39.4 C (102.9 F)
1950
37.2 C (99.0 F)
1951
37.2 C (99.0 F)
1952
37.2 C (99.0 F)
1953
38.3 C (100.9 F)
1954
39.4 C (102.9 F)
1955
38.3 C (100.9 F)
1956
37.2 C (99.0 F)
1957
36.7 C (98.1 F)
1958
37.8 C (100.0 F)
1959
38.3 C (100.9 F)
1960
25.6 C (78.1 F)
1966
37.8 C (100.0 F)
1967
36.1 C (97.0 F)
1968
38.9 C (102.0 F)
1969
37.2 C (99.0 F)
1970
37.8 C (100.0 F)
1971
40.6 C (105.1 F)
1972
37.2 C (99.0 F)
1973
38.3 C (100.9 F)
1974
37.8 C (100.0 F)
1975
37.2 C (99.0 F)
1976
38.3 C (100.9 F)
1977
38.9 C (102.0 F)
1978
38.3 C (100.9 F)
1979
38.3 C (100.9 F)
1980
37.8 C (100.0 F)
1981
41.1 C (106.0 F)
1982
38.9 C (102.0 F)
1983
41.1 C (106.0 F)
1984
38.3 C (100.9 F)
1985
39.4 C (102.9 F)
1986
38.9 C (102.0 F)
1987
39.4 C (102.9 F)
1988
38.3 C (100.9 F)
1989
38.9 C (102.0 F)
1990
38.3 C (100.9 F)
1991
35.6 C (96.1 F)
1992
35.0 C (95.0 F)
1993
7.2 C (45.0 F)
Coldest night (TNn)
The coldest night of the year at Bonanza, 1938 to 1993. The record is -35.6 C (-32.1 F) in 1990, marked on the chart; the median year is -25.6 C (-14.1 F).
Coldest night (TNn) at Bonanza by year
Year
Coldest night (TNn)
1938
-20.6 C (-5.1 F)
1939
-24.4 C (-11.9 F)
1940
-27.2 C (-17.0 F)
1941
-26.1 C (-15.0 F)
1942
-28.9 C (-20.0 F)
1943
-21.7 C (-7.1 F)
1944
-25.6 C (-14.1 F)
1945
-21.1 C (-6.0 F)
1946
-21.1 C (-6.0 F)
1947
-21.7 C (-7.1 F)
1948
-26.7 C (-16.1 F)
1949
-30.0 C (-22.0 F)
1950
-29.4 C (-20.9 F)
1951
-28.3 C (-18.9 F)
1952
-31.7 C (-25.1 F)
1953
-19.4 C (-2.9 F)
1954
-20.6 C (-5.1 F)
1955
-26.1 C (-15.0 F)
1956
-23.3 C (-9.9 F)
1957
-26.1 C (-15.0 F)
1958
-18.9 C (-2.0 F)
1959
-20.6 C (-5.1 F)
1960
-25.0 C (-13.0 F)
1966
-24.4 C (-11.9 F)
1967
-22.8 C (-9.0 F)
1968
-26.7 C (-16.1 F)
1969
-20.0 C (-4.0 F)
1970
-22.2 C (-8.0 F)
1971
-29.4 C (-20.9 F)
1972
-22.2 C (-8.0 F)
1973
-27.8 C (-18.0 F)
1974
-29.4 C (-20.9 F)
1975
-21.1 C (-6.0 F)
1976
-22.8 C (-9.0 F)
1977
-20.0 C (-4.0 F)
1978
-27.8 C (-18.0 F)
1979
-30.6 C (-23.1 F)
1980
-22.2 C (-8.0 F)
1981
-15.6 C (3.9 F)
1982
-25.6 C (-14.1 F)
1983
-23.3 C (-9.9 F)
1984
-31.1 C (-24.0 F)
1985
-30.0 C (-22.0 F)
1986
-16.1 C (3.0 F)
1987
-25.0 C (-13.0 F)
1988
-25.6 C (-14.1 F)
1989
-33.3 C (-27.9 F)
1990
-35.6 C (-32.1 F)
1991
-26.1 C (-15.0 F)
1992
-27.8 C (-18.0 F)
1993
-27.8 C (-18.0 F)
Wettest day (Rx1day)
The wettest day of the year at Bonanza, 1938 to 1993. The record is 47.8 mm (1.9 in) in 1970, marked on the chart; the median year is 20.8 mm (0.8 in).
Wettest day (Rx1day) at Bonanza by year
Year
Wettest day (Rx1day)
1938
30.2 mm (1.2 in)
1939
22.9 mm (0.9 in)
1940
21.3 mm (0.8 in)
1941
30.5 mm (1.2 in)
1942
14.0 mm (0.6 in)
1943
24.9 mm (1.0 in)
1944
18.5 mm (0.7 in)
1945
15.5 mm (0.6 in)
1946
25.4 mm (1.0 in)
1947
19.6 mm (0.8 in)
1948
15.7 mm (0.6 in)
1949
21.1 mm (0.8 in)
1950
18.5 mm (0.7 in)
1951
23.6 mm (0.9 in)
1952
16.5 mm (0.6 in)
1953
16.5 mm (0.6 in)
1954
19.6 mm (0.8 in)
1955
14.0 mm (0.6 in)
1956
36.8 mm (1.4 in)
1957
18.8 mm (0.7 in)
1958
33.0 mm (1.3 in)
1959
14.2 mm (0.6 in)
1960
7.1 mm (0.28 in)
1966
31.2 mm (1.2 in)
1967
18.3 mm (0.7 in)
1968
13.7 mm (0.5 in)
1969
22.9 mm (0.9 in)
1970
47.8 mm (1.9 in)
1971
13.5 mm (0.5 in)
1972
20.8 mm (0.8 in)
1973
17.3 mm (0.7 in)
1974
12.7 mm (0.5 in)
1975
25.9 mm (1.0 in)
1976
15.5 mm (0.6 in)
1977
18.0 mm (0.7 in)
1978
18.0 mm (0.7 in)
1979
27.4 mm (1.1 in)
1980
21.3 mm (0.8 in)
1981
14.0 mm (0.6 in)
1982
25.9 mm (1.0 in)
1983
25.7 mm (1.0 in)
1984
27.9 mm (1.1 in)
1985
36.8 mm (1.4 in)
1986
24.9 mm (1.0 in)
1987
20.8 mm (0.8 in)
1988
11.9 mm (0.5 in)
1989
22.4 mm (0.9 in)
1990
19.1 mm (0.8 in)
1991
26.2 mm (1.0 in)
1992
21.1 mm (0.8 in)
1993
12.7 mm (0.5 in)
Wettest five days (Rx5day)
The wettest five days of the year at Bonanza, 1938 to 1993. The record is 80.6 mm (3.2 in) in 1970, marked on the chart; the median year is 30.5 mm (1.2 in).
Wettest five days (Rx5day) at Bonanza by year
Year
Wettest five days (Rx5day)
1938
49.2 mm (1.9 in)
1939
42.4 mm (1.7 in)
1940
39.1 mm (1.5 in)
1941
45.7 mm (1.8 in)
1942
27.8 mm (1.1 in)
1943
30.0 mm (1.2 in)
1944
28.0 mm (1.1 in)
1945
23.4 mm (0.9 in)
1946
35.6 mm (1.4 in)
1947
19.6 mm (0.8 in)
1948
21.5 mm (0.8 in)
1949
33.6 mm (1.3 in)
1950
18.8 mm (0.7 in)
1951
34.8 mm (1.4 in)
1952
28.4 mm (1.1 in)
1953
25.4 mm (1.0 in)
1954
35.6 mm (1.4 in)
1955
19.6 mm (0.8 in)
1956
38.1 mm (1.5 in)
1957
27.9 mm (1.1 in)
1958
33.5 mm (1.3 in)
1959
27.6 mm (1.1 in)
1960
8.1 mm (0.32 in)
1966
41.6 mm (1.6 in)
1967
37.4 mm (1.5 in)
1968
21.3 mm (0.8 in)
1969
30.5 mm (1.2 in)
1970
80.6 mm (3.2 in)
1971
21.8 mm (0.9 in)
1972
20.8 mm (0.8 in)
1973
29.2 mm (1.1 in)
1974
20.4 mm (0.8 in)
1975
37.3 mm (1.5 in)
1976
28.5 mm (1.1 in)
1977
23.4 mm (0.9 in)
1978
18.0 mm (0.7 in)
1979
60.3 mm (2.4 in)
1980
31.8 mm (1.3 in)
1981
27.5 mm (1.1 in)
1982
50.6 mm (2.0 in)
1983
38.4 mm (1.5 in)
1984
48.1 mm (1.9 in)
1985
72.4 mm (2.9 in)
1986
41.2 mm (1.6 in)
1987
32.5 mm (1.3 in)
1988
15.0 mm (0.6 in)
1989
33.3 mm (1.3 in)
1990
29.8 mm (1.2 in)
1991
41.4 mm (1.6 in)
1992
40.2 mm (1.6 in)
1993
19.8 mm (0.8 in)
Longest dry spell (CDD)
The longest dry spell of the year at Bonanza, 1938 to 1993. The record is 104 days in 1972, marked on the chart; the median year is 43 days.
Longest dry spell (CDD) at Bonanza by year
Year
Longest dry spell (CDD)
1938
34 days
1939
34 days
1940
55 days
1941
32 days
1942
67 days
1943
39 days
1944
44 days
1945
61 days
1946
45 days
1947
49 days
1948
92 days
1949
51 days
1950
58 days
1951
47 days
1952
90 days
1953
34 days
1954
27 days
1955
49 days
1956
35 days
1957
32 days
1958
63 days
1959
36 days
1960
30 days
1966
25 days
1967
45 days
1968
53 days
1969
46 days
1970
30 days
1971
39 days
1972
104 days
1973
43 days
1974
87 days
1975
74 days
1976
90 days
1977
29 days
1978
43 days
1979
53 days
1980
42 days
1981
30 days
1982
28 days
1983
27 days
1984
44 days
1985
28 days
1986
31 days
1987
48 days
1988
47 days
1989
28 days
1990
21 days
1991
30 days
1992
30 days
1993
19 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
31 years with a frost
Across 31 years with a frost, the median last spring frost at Bonanza falls on 9 May and the median first autumn frost on 6 October, which leaves a median of 148 days between them.
Fitted over all years, the growing season changes by -3.9 days per decade at this station.
Frost dates and growing season at Bonanza
Measure
Median, all years
Earliest period
Recent period (1940 to 1990)
Recent against earliest
Fitted trend
Last spring frost
9 May
n/a
10 May
n/a
+3.6 days per decade
First autumn frost
6 October
n/a
6 October
n/a
-0.3 days per decade
Growing days
148 days
n/a
148 days
n/a
-3.9 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
40 years, 1941 to 1992
A day with at least 20.0 mm (0.8 in) of rain is expected about once in 2 years. A day with at least 49.4 mm (1.9 in) of rain is expected about once in 100 years.
Rainfall return levels at Bonanza: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
20.0 mm (0.8 in)
5 years
26.5 mm (1.0 in)
10 years
31.3 mm (1.2 in)
25 years
38.0 mm (1.5 in)
50 years
43.5 mm (1.7 in)
Longer than the 40 years of record
100 years
49.4 mm (1.9 in)
Longer than the 40 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, 40 years of values from 1941 to 1992.
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: 47.8 mm (1.9 in) in 1970; 36.8 mm (1.4 in) in 1956; 36.8 mm (1.4 in) in 1985.
Download the Data
Data for Bonanza standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Bonanza 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 2026-10-14 (14 October 2026). Records are computed by this site and are not official.