Record envelope, standing records and threshold days for Arco (USC00100375), Idaho, United States, with 113 years of record.
Key Facts for Arco
Arco (USC00100375) is a weather station in Idaho, United States at 43.64 latitude and -113.30 longitude, 1,623 m (5,325 ft) above sea level.
The station reports from 1914 to 2026, 113 years of record.
1,464 records set at Arco still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Arco set a daily record high minimum temperature of 18.9 C (66.0 F) on 20 July 2026.
About the Station
Location: Idaho, United States, 43.64 latitude, -113.30 longitude.
Elevation: 1,623 m (5,325 ft).
Period of record: 1914 to 2026, 113 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
3 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 Arco. The lines show the 2026 daily maximum and minimum. 3 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Arco, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
11.1 C (52.0 F)
-43.3 C (-45.9 F)
8.3 C (46.9 F)
-16.7 C (1.9 F)
Feb
15.0 C (59.0 F)
-35.6 C (-32.1 F)
12.8 C (55.0 F)
-13.9 C (7.0 F)
Mar
21.7 C (71.1 F)
-28.9 C (-20.0 F)
n/a
n/a
Apr
30.6 C (87.1 F)
-19.4 C (-2.9 F)
22.8 C (73.0 F)
-6.1 C (21.0 F)
May
35.0 C (95.0 F)
-11.7 C (10.9 F)
30.0 C (86.0 F)
-2.8 C (27.0 F)
Jun
36.1 C (97.0 F)
-6.7 C (19.9 F)
32.8 C (91.0 F)
1.7 C (35.1 F)
Jul
38.9 C (102.0 F)
-1.7 C (28.9 F)
36.7 C (98.1 F)
7.8 C (46.0 F)
Aug
37.8 C (100.0 F)
-3.9 C (25.0 F)
32.2 C (90.0 F)
11.7 C (53.1 F)
Sep
37.8 C (100.0 F)
-11.7 C (10.9 F)
n/a
n/a
Oct
29.4 C (84.9 F)
-17.2 C (1.0 F)
n/a
n/a
Nov
21.1 C (70.0 F)
-30.0 C (-22.0 F)
n/a
n/a
Dec
15.0 C (59.0 F)
-42.8 C (-45.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Arco still stand. 1934 holds the most, with 42.
Standing records at Arco by the year they were set
Year set
Standing records
1914
22
1915
17
1916
17
1917
27
1920
10
1921
15
1922
14
1923
12
1924
11
1925
6
1926
20
1927
13
1928
11
1929
28
1930
17
1931
4
1932
17
1933
23
1934
42
1935
15
1936
25
1937
36
1938
7
1939
13
1940
6
1941
9
1942
18
1944
1
1945
8
1946
4
1947
6
1948
5
1949
6
1950
22
1951
1
1952
15
1953
13
1954
9
1955
22
1956
8
1957
7
1958
8
1959
9
1960
20
1961
12
1962
14
1963
15
1964
15
1965
13
1966
16
1967
5
1968
15
1969
18
1970
9
1971
10
1972
23
1973
8
1974
11
1975
17
1976
6
1977
17
1978
7
1979
6
1980
11
1981
8
1982
13
1983
13
1984
10
1985
21
1986
9
1987
20
1988
20
1989
16
1990
25
1991
14
1992
17
1993
13
1994
10
1995
2
1996
18
1997
3
1998
7
1999
12
2000
11
2001
9
2002
21
2003
37
2004
11
2005
3
2006
11
2007
8
2008
4
2009
4
2010
19
2011
6
2012
11
2013
20
2014
10
2015
30
2016
9
2017
9
2018
4
2019
15
2020
10
2021
14
2022
19
2023
16
2024
9
2025
14
2026
12
All-Time Record Progression
5 new records
5 all-time records were set at Arco between 15 May 1962 and 8 February 1985. Each dot is a new record.
When Arco set new all-time records
Date
Kind
Detail
1962-05-15
Record daily precipitation
Record daily precipitation 48.0 mm (1.9 in)
1972-12-10
Record low maximum temperature
Record low maximum temperature -21.7 C (-7.1 F)
1983-12-22
Record low maximum temperature
Record low maximum temperature -22.8 C (-9.0 F)
1983-12-23
Record low maximum temperature
Record low maximum temperature -25.0 C (-13.0 F)
1985-02-08
Record daily precipitation
Record daily precipitation 62.0 mm (2.4 in)
Wettest Day of Each Month
Feb: 62.0 mm (2.4 in)
The wettest day on record for each calendar month at Arco. The most was 62.0 mm (2.4 in) on 8 February 1985.
Record daily precipitation for each month at Arco
Month
Record daily precipitation (mm)
Date
Jan
26.7 mm (1.1 in)
10 January 1968
Feb
62.0 mm (2.4 in)
8 February 1985
Mar
30.5 mm (1.2 in)
27 March 1985
Apr
41.7 mm (1.6 in)
20 April 1981
May
48.0 mm (1.9 in)
15 May 1962
Jun
31.8 mm (1.3 in)
6 June 1993
Jul
35.6 mm (1.4 in)
2 July 1997
Aug
41.9 mm (1.6 in)
2 August 2011
Sep
36.6 mm (1.4 in)
5 September 2007
Oct
26.7 mm (1.1 in)
17 October 1938
Nov
24.1 mm (0.9 in)
7 November 1928
Dec
42.9 mm (1.7 in)
25 December 2008
Period of Record Coverage
1914 to 2026
Complete yearUnder 90 percent of days
110 years of record at Arco, 1914 to 2026. 43 years have data for under 90 percent of days and are left out of rankings: 1914, 1916, 1917, 1924, 1925, 1926, 1927, 1928 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 57 complete years at Arco, 1921 to 2025. Blue stripes are years cooler than the station's own mean of 6.0 C (42.8 F); red stripes are warmer. The coolest year was 1964, at 3.8 C (38.8 F), and the warmest was 1934, at 9.4 C (49.0 F). The strongest colour marks a difference of 3.5 C (6.3 F).
Annual mean temperature at Arco as warming stripes, 1921 to 2025
Year
Annual mean temperature
Difference from the station mean
1921
6.3 C
+0.25 C
1923
5.1 C
-0.94 C
1932
4.5 C
-1.49 C
1933
5.8 C
-0.25 C
1934
9.4 C
+3.41 C
1935
5.9 C
-0.12 C
1937
5.8 C
-0.18 C
1941
6.4 C
+0.33 C
1947
6.0 C
+0.00 C
1948
5.3 C
-0.74 C
1952
4.7 C
-1.36 C
1953
6.9 C
+0.87 C
1954
6.3 C
+0.31 C
1955
4.5 C
-1.56 C
1956
5.3 C
-0.69 C
1957
5.2 C
-0.84 C
1958
6.4 C
+0.41 C
1959
5.8 C
-0.23 C
1962
5.7 C
-0.37 C
1963
6.0 C
-0.06 C
1964
3.8 C
-2.22 C
1965
5.1 C
-0.95 C
1966
5.4 C
-0.67 C
1967
5.3 C
-0.70 C
1968
4.8 C
-1.24 C
1969
5.0 C
-1.01 C
1970
5.9 C
-0.13 C
1971
5.0 C
-1.07 C
1972
5.3 C
-0.70 C
1975
4.6 C
-1.46 C
1976
5.6 C
-0.47 C
1977
5.9 C
-0.16 C
1982
4.9 C
-1.16 C
1987
7.6 C
+1.54 C
1989
5.3 C
-0.73 C
1990
6.5 C
+0.43 C
1991
6.4 C
+0.40 C
1992
7.3 C
+1.26 C
1999
6.7 C
+0.71 C
2000
7.4 C
+1.38 C
2001
6.8 C
+0.79 C
2002
6.2 C
+0.21 C
2003
8.4 C
+2.40 C
2004
6.8 C
+0.74 C
2005
6.1 C
+0.04 C
2006
6.4 C
+0.41 C
2011
5.3 C
-0.72 C
2013
6.7 C
+0.68 C
2014
7.8 C
+1.80 C
2015
8.0 C
+1.95 C
2016
6.6 C
+0.57 C
2018
6.5 C
+0.52 C
2019
4.4 C
-1.63 C
2020
5.5 C
-0.49 C
2023
5.7 C
-0.35 C
2024
7.4 C
+1.42 C
2025
7.7 C
+1.71 C
The annual mean temperature here has risen by 0.12 C (0.02 to 0.22) per decade over 1921 to 2025. In Fahrenheit: 0.22 F (0.04 to 0.39) per decade. The slope is a straight line fitted to 57 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Arco
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.12 C (0.02 to 0.22) per decade
0.22 F (0.04 to 0.39) per decade
1921 to 2025
57
Rise
Mean daily maximum
-0.04 C (-0.14 to 0.07) per decade
-0.1 F (-0.3 to 0.1) per decade
1921 to 2025
57
Not clearly different from zero
Mean daily minimum
0.3 C (0.2 to 0.4) per decade
0.5 F (0.3 to 0.7) per decade
1921 to 2025
57
Rise
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
1914 to 2026
Yearly extremes at Arco: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
38.9 C (102.0 F)
1934
35.0 C (95.0 F)
110
Coldest night (TNn)
-43.3 C (-45.9 F)
1937
-28.9 C (-20.0 F)
110
Wettest day (Rx1day)
62.0 mm (2.4 in)
1985
21.0 mm (0.8 in)
110
Wettest five days (Rx5day)
88.9 mm (3.5 in)
1931
33.2 mm (1.3 in)
110
Longest dry spell (CDD)
114 days
1936
44 days
110
Hottest day (TXx)
The hottest day of the year at Arco, 1914 to 2026. The record is 38.9 C (102.0 F) in 1934, marked on the chart; the median year is 35.0 C (95.0 F).
Hottest day (TXx) at Arco by year
Year
Hottest day (TXx)
1914
31.7 C (89.1 F)
1915
32.8 C (91.0 F)
1916
31.7 C (89.1 F)
1917
15.0 C (59.0 F)
1920
36.1 C (97.0 F)
1921
36.1 C (97.0 F)
1922
35.6 C (96.1 F)
1923
35.6 C (96.1 F)
1924
35.6 C (96.1 F)
1925
38.3 C (100.9 F)
1926
35.6 C (96.1 F)
1927
37.8 C (100.0 F)
1928
30.6 C (87.1 F)
1929
36.7 C (98.1 F)
1930
35.6 C (96.1 F)
1931
38.3 C (100.9 F)
1932
34.4 C (93.9 F)
1933
37.8 C (100.0 F)
1934
38.9 C (102.0 F)
1935
37.8 C (100.0 F)
1936
37.8 C (100.0 F)
1937
38.9 C (102.0 F)
1938
30.6 C (87.1 F)
1939
36.7 C (98.1 F)
1940
37.8 C (100.0 F)
1941
37.8 C (100.0 F)
1942
36.1 C (97.0 F)
1944
13.9 C (57.0 F)
1945
33.9 C (93.0 F)
1946
34.4 C (93.9 F)
1947
35.0 C (95.0 F)
1948
34.4 C (93.9 F)
1949
35.6 C (96.1 F)
1950
35.6 C (96.1 F)
1951
29.4 C (84.9 F)
1952
33.9 C (93.0 F)
1953
34.4 C (93.9 F)
1954
36.1 C (97.0 F)
1955
36.1 C (97.0 F)
1956
36.7 C (98.1 F)
1957
32.2 C (90.0 F)
1958
34.4 C (93.9 F)
1959
37.2 C (99.0 F)
1960
38.9 C (102.0 F)
1961
37.8 C (100.0 F)
1962
35.6 C (96.1 F)
1963
33.9 C (93.0 F)
1964
33.3 C (91.9 F)
1965
32.8 C (91.0 F)
1966
35.0 C (95.0 F)
1967
35.0 C (95.0 F)
1968
32.8 C (91.0 F)
1969
34.4 C (93.9 F)
1970
35.0 C (95.0 F)
1971
35.0 C (95.0 F)
1972
34.4 C (93.9 F)
1973
35.6 C (96.1 F)
1974
35.0 C (95.0 F)
1975
34.4 C (93.9 F)
1976
35.0 C (95.0 F)
1977
33.3 C (91.9 F)
1978
34.4 C (93.9 F)
1979
33.9 C (93.0 F)
1980
34.4 C (93.9 F)
1981
35.6 C (96.1 F)
1982
35.0 C (95.0 F)
1983
35.6 C (96.1 F)
1984
35.6 C (96.1 F)
1985
36.1 C (97.0 F)
1986
34.4 C (93.9 F)
1987
35.0 C (95.0 F)
1988
36.1 C (97.0 F)
1989
36.1 C (97.0 F)
1990
37.2 C (99.0 F)
1991
36.1 C (97.0 F)
1992
35.6 C (96.1 F)
1993
30.6 C (87.1 F)
1994
35.6 C (96.1 F)
1995
15.6 C (60.1 F)
1996
35.0 C (95.0 F)
1997
32.2 C (90.0 F)
1998
36.7 C (98.1 F)
1999
34.4 C (93.9 F)
2000
37.8 C (100.0 F)
2001
36.7 C (98.1 F)
2002
38.3 C (100.9 F)
2003
38.3 C (100.9 F)
2004
33.9 C (93.0 F)
2005
35.6 C (96.1 F)
2006
36.7 C (98.1 F)
2007
37.8 C (100.0 F)
2008
35.0 C (95.0 F)
2009
34.4 C (93.9 F)
2010
33.9 C (93.0 F)
2011
33.9 C (93.0 F)
2012
35.0 C (95.0 F)
2013
36.1 C (97.0 F)
2014
35.6 C (96.1 F)
2015
36.1 C (97.0 F)
2016
34.4 C (93.9 F)
2017
34.4 C (93.9 F)
2018
35.0 C (95.0 F)
2019
33.9 C (93.0 F)
2020
35.0 C (95.0 F)
2021
35.0 C (95.0 F)
2022
35.0 C (95.0 F)
2023
35.0 C (95.0 F)
2024
36.1 C (97.0 F)
2025
34.4 C (93.9 F)
2026
36.7 C (98.1 F)
Coldest night (TNn)
The coldest night of the year at Arco, 1914 to 2026. The record is -43.3 C (-45.9 F) in 1937, marked on the chart; the median year is -28.9 C (-20.0 F).
Coldest night (TNn) at Arco by year
Year
Coldest night (TNn)
1914
-28.3 C (-18.9 F)
1915
-30.6 C (-23.1 F)
1916
-36.7 C (-34.1 F)
1917
-35.0 C (-31.0 F)
1920
-26.1 C (-15.0 F)
1921
-26.1 C (-15.0 F)
1922
-34.4 C (-29.9 F)
1923
-28.3 C (-18.9 F)
1924
-26.7 C (-16.1 F)
1925
-18.3 C (-0.9 F)
1926
-21.1 C (-6.0 F)
1927
-31.7 C (-25.1 F)
1928
-28.9 C (-20.0 F)
1929
-35.6 C (-32.1 F)
1930
-22.8 C (-9.0 F)
1931
-28.9 C (-20.0 F)
1932
-32.8 C (-27.0 F)
1933
-34.4 C (-29.9 F)
1934
-17.2 C (1.0 F)
1935
-37.2 C (-35.0 F)
1936
-28.3 C (-18.9 F)
1937
-43.3 C (-45.9 F)
1938
-23.9 C (-11.0 F)
1939
-28.9 C (-20.0 F)
1940
-23.9 C (-11.0 F)
1941
-27.8 C (-18.0 F)
1942
-33.9 C (-29.0 F)
1944
-21.7 C (-7.1 F)
1945
-24.4 C (-11.9 F)
1946
-20.0 C (-4.0 F)
1947
-27.2 C (-17.0 F)
1948
-29.4 C (-20.9 F)
1949
-34.4 C (-29.9 F)
1950
-34.4 C (-29.9 F)
1951
-28.3 C (-18.9 F)
1952
-32.8 C (-27.0 F)
1953
-19.4 C (-2.9 F)
1954
-24.4 C (-11.9 F)
1955
-28.9 C (-20.0 F)
1956
-32.8 C (-27.0 F)
1957
-30.6 C (-23.1 F)
1958
-23.9 C (-11.0 F)
1959
-31.7 C (-25.1 F)
1960
-32.2 C (-26.0 F)
1961
-28.3 C (-18.9 F)
1962
-33.3 C (-27.9 F)
1963
-35.0 C (-31.0 F)
1964
-30.0 C (-22.0 F)
1965
-27.2 C (-17.0 F)
1966
-28.3 C (-18.9 F)
1967
-27.2 C (-17.0 F)
1968
-30.0 C (-22.0 F)
1969
-24.4 C (-11.9 F)
1970
-27.8 C (-18.0 F)
1971
-31.7 C (-25.1 F)
1972
-38.3 C (-36.9 F)
1973
-32.8 C (-27.0 F)
1974
-30.0 C (-22.0 F)
1975
-31.1 C (-24.0 F)
1976
-27.2 C (-17.0 F)
1977
-32.2 C (-26.0 F)
1978
-28.9 C (-20.0 F)
1979
-31.1 C (-24.0 F)
1980
-33.3 C (-27.9 F)
1981
-32.2 C (-26.0 F)
1982
-34.4 C (-29.9 F)
1983
-42.8 C (-45.0 F)
1984
-37.2 C (-35.0 F)
1985
-37.2 C (-35.0 F)
1986
-27.8 C (-18.0 F)
1987
-25.6 C (-14.1 F)
1988
-31.1 C (-24.0 F)
1989
-35.6 C (-32.1 F)
1990
-40.0 C (-40.0 F)
1991
-26.7 C (-16.1 F)
1992
-31.1 C (-24.0 F)
1993
-31.1 C (-24.0 F)
1994
-27.2 C (-17.0 F)
1995
-26.7 C (-16.1 F)
1996
-35.0 C (-31.0 F)
1997
-25.6 C (-14.1 F)
1998
-27.2 C (-17.0 F)
1999
-22.8 C (-9.0 F)
2000
-19.4 C (-2.9 F)
2001
-26.1 C (-15.0 F)
2002
-30.6 C (-23.1 F)
2003
-18.9 C (-2.0 F)
2004
-29.4 C (-20.9 F)
2005
-27.8 C (-18.0 F)
2006
-25.6 C (-14.1 F)
2007
-23.9 C (-11.0 F)
2008
-26.7 C (-16.1 F)
2009
-28.9 C (-20.0 F)
2010
-30.0 C (-22.0 F)
2011
-28.3 C (-18.9 F)
2012
-22.2 C (-8.0 F)
2013
-28.9 C (-20.0 F)
2014
-26.1 C (-15.0 F)
2015
-30.0 C (-22.0 F)
2016
-28.9 C (-20.0 F)
2017
-28.9 C (-20.0 F)
2018
-22.8 C (-9.0 F)
2019
-22.8 C (-9.0 F)
2020
-21.7 C (-7.1 F)
2021
-25.6 C (-14.1 F)
2022
-29.4 C (-20.9 F)
2023
-31.1 C (-24.0 F)
2024
-23.9 C (-11.0 F)
2025
-25.6 C (-14.1 F)
2026
-16.7 C (1.9 F)
Wettest day (Rx1day)
The wettest day of the year at Arco, 1914 to 2026. The record is 62.0 mm (2.4 in) in 1985, marked on the chart; the median year is 21.0 mm (0.8 in).
Wettest day (Rx1day) at Arco by year
Year
Wettest day (Rx1day)
1914
16.3 mm (0.6 in)
1915
17.8 mm (0.7 in)
1916
11.4 mm (0.4 in)
1917
19.1 mm (0.8 in)
1920
20.3 mm (0.8 in)
1921
15.2 mm (0.6 in)
1922
21.1 mm (0.8 in)
1923
33.5 mm (1.3 in)
1924
10.2 mm (0.4 in)
1925
22.9 mm (0.9 in)
1926
14.7 mm (0.6 in)
1927
18.5 mm (0.7 in)
1928
24.1 mm (0.9 in)
1929
24.6 mm (1.0 in)
1930
20.8 mm (0.8 in)
1931
39.4 mm (1.6 in)
1932
13.7 mm (0.5 in)
1933
12.7 mm (0.5 in)
1934
17.8 mm (0.7 in)
1935
24.1 mm (0.9 in)
1936
26.7 mm (1.1 in)
1937
22.4 mm (0.9 in)
1938
26.7 mm (1.1 in)
1939
22.9 mm (0.9 in)
1940
15.0 mm (0.6 in)
1941
25.1 mm (1.0 in)
1942
15.0 mm (0.6 in)
1944
13.0 mm (0.5 in)
1945
22.1 mm (0.9 in)
1946
21.8 mm (0.9 in)
1947
16.3 mm (0.6 in)
1948
30.5 mm (1.2 in)
1949
15.7 mm (0.6 in)
1950
20.3 mm (0.8 in)
1951
9.1 mm (0.36 in)
1952
25.1 mm (1.0 in)
1953
26.7 mm (1.1 in)
1954
19.6 mm (0.8 in)
1955
19.3 mm (0.8 in)
1956
17.8 mm (0.7 in)
1957
26.9 mm (1.1 in)
1958
18.0 mm (0.7 in)
1959
19.6 mm (0.8 in)
1960
17.5 mm (0.7 in)
1961
27.2 mm (1.1 in)
1962
48.0 mm (1.9 in)
1963
31.0 mm (1.2 in)
1964
23.6 mm (0.9 in)
1965
24.6 mm (1.0 in)
1966
24.1 mm (0.9 in)
1967
22.6 mm (0.9 in)
1968
33.3 mm (1.3 in)
1969
25.4 mm (1.0 in)
1970
23.6 mm (0.9 in)
1971
25.9 mm (1.0 in)
1972
23.1 mm (0.9 in)
1973
13.2 mm (0.5 in)
1974
14.2 mm (0.6 in)
1975
14.0 mm (0.6 in)
1976
30.5 mm (1.2 in)
1977
20.3 mm (0.8 in)
1978
20.3 mm (0.8 in)
1979
19.1 mm (0.8 in)
1980
39.9 mm (1.6 in)
1981
41.7 mm (1.6 in)
1982
32.0 mm (1.3 in)
1983
27.4 mm (1.1 in)
1984
35.6 mm (1.4 in)
1985
62.0 mm (2.4 in)
1986
56.4 mm (2.2 in)
1987
21.6 mm (0.9 in)
1988
26.7 mm (1.1 in)
1989
9.9 mm (0.39 in)
1990
30.7 mm (1.2 in)
1991
20.1 mm (0.8 in)
1992
17.8 mm (0.7 in)
1993
31.8 mm (1.3 in)
1994
19.1 mm (0.8 in)
1995
7.9 mm (0.31 in)
1996
15.2 mm (0.6 in)
1997
35.6 mm (1.4 in)
1998
17.8 mm (0.7 in)
1999
17.0 mm (0.7 in)
2000
30.0 mm (1.2 in)
2001
10.7 mm (0.4 in)
2002
23.9 mm (0.9 in)
2003
18.8 mm (0.7 in)
2004
18.0 mm (0.7 in)
2005
21.3 mm (0.8 in)
2006
22.9 mm (0.9 in)
2007
36.6 mm (1.4 in)
2008
42.9 mm (1.7 in)
2009
15.2 mm (0.6 in)
2010
23.9 mm (0.9 in)
2011
41.9 mm (1.6 in)
2012
13.2 mm (0.5 in)
2013
7.9 mm (0.31 in)
2014
20.8 mm (0.8 in)
2015
19.1 mm (0.8 in)
2016
19.3 mm (0.8 in)
2017
20.1 mm (0.8 in)
2018
27.9 mm (1.1 in)
2019
17.8 mm (0.7 in)
2020
20.1 mm (0.8 in)
2021
22.9 mm (0.9 in)
2022
20.6 mm (0.8 in)
2023
29.2 mm (1.1 in)
2024
17.8 mm (0.7 in)
2025
23.4 mm (0.9 in)
2026
17.5 mm (0.7 in)
Wettest five days (Rx5day)
The wettest five days of the year at Arco, 1914 to 2026. The record is 88.9 mm (3.5 in) in 1931, marked on the chart; the median year is 33.2 mm (1.3 in).
Wettest five days (Rx5day) at Arco by year
Year
Wettest five days (Rx5day)
1914
25.9 mm (1.0 in)
1915
28.5 mm (1.1 in)
1916
20.9 mm (0.8 in)
1917
19.1 mm (0.8 in)
1920
28.0 mm (1.1 in)
1921
28.0 mm (1.1 in)
1922
30.2 mm (1.2 in)
1923
44.6 mm (1.8 in)
1924
17.8 mm (0.7 in)
1925
27.5 mm (1.1 in)
1926
26.1 mm (1.0 in)
1927
29.4 mm (1.2 in)
1928
30.5 mm (1.2 in)
1929
44.9 mm (1.8 in)
1930
31.8 mm (1.3 in)
1931
88.9 mm (3.5 in)
1932
35.1 mm (1.4 in)
1933
33.0 mm (1.3 in)
1934
23.9 mm (0.9 in)
1935
30.9 mm (1.2 in)
1936
31.0 mm (1.2 in)
1937
37.1 mm (1.5 in)
1938
36.9 mm (1.5 in)
1939
28.2 mm (1.1 in)
1940
33.3 mm (1.3 in)
1941
34.2 mm (1.3 in)
1942
21.8 mm (0.9 in)
1944
18.0 mm (0.7 in)
1945
34.6 mm (1.4 in)
1946
31.8 mm (1.3 in)
1947
21.6 mm (0.9 in)
1948
34.1 mm (1.3 in)
1949
20.4 mm (0.8 in)
1950
33.0 mm (1.3 in)
1951
9.6 mm (0.38 in)
1952
48.8 mm (1.9 in)
1953
26.7 mm (1.1 in)
1954
22.4 mm (0.9 in)
1955
44.9 mm (1.8 in)
1956
25.4 mm (1.0 in)
1957
38.7 mm (1.5 in)
1958
21.6 mm (0.9 in)
1959
38.9 mm (1.5 in)
1960
21.9 mm (0.9 in)
1961
29.5 mm (1.2 in)
1962
60.1 mm (2.4 in)
1963
52.8 mm (2.1 in)
1964
65.4 mm (2.6 in)
1965
47.8 mm (1.9 in)
1966
51.5 mm (2.0 in)
1967
38.3 mm (1.5 in)
1968
64.5 mm (2.5 in)
1969
63.7 mm (2.5 in)
1970
58.6 mm (2.3 in)
1971
38.1 mm (1.5 in)
1972
25.4 mm (1.0 in)
1973
26.4 mm (1.0 in)
1974
24.4 mm (1.0 in)
1975
30.5 mm (1.2 in)
1976
33.0 mm (1.3 in)
1977
41.2 mm (1.6 in)
1978
46.0 mm (1.8 in)
1979
21.7 mm (0.9 in)
1980
43.9 mm (1.7 in)
1981
55.7 mm (2.2 in)
1982
42.2 mm (1.7 in)
1983
39.3 mm (1.5 in)
1984
35.6 mm (1.4 in)
1985
64.5 mm (2.5 in)
1986
71.6 mm (2.8 in)
1987
47.5 mm (1.9 in)
1988
40.4 mm (1.6 in)
1989
18.1 mm (0.7 in)
1990
40.0 mm (1.6 in)
1991
36.4 mm (1.4 in)
1992
22.9 mm (0.9 in)
1993
61.7 mm (2.4 in)
1994
27.0 mm (1.1 in)
1995
13.2 mm (0.5 in)
1996
35.6 mm (1.4 in)
1997
35.6 mm (1.4 in)
1998
19.9 mm (0.8 in)
1999
37.9 mm (1.5 in)
2000
36.6 mm (1.4 in)
2001
25.6 mm (1.0 in)
2002
23.9 mm (0.9 in)
2003
37.4 mm (1.5 in)
2004
25.9 mm (1.0 in)
2005
35.1 mm (1.4 in)
2006
41.0 mm (1.6 in)
2007
38.7 mm (1.5 in)
2008
56.3 mm (2.2 in)
2009
26.4 mm (1.0 in)
2010
32.8 mm (1.3 in)
2011
63.4 mm (2.5 in)
2012
21.4 mm (0.8 in)
2013
8.4 mm (0.33 in)
2014
35.8 mm (1.4 in)
2015
38.0 mm (1.5 in)
2016
30.7 mm (1.2 in)
2017
37.8 mm (1.5 in)
2018
47.4 mm (1.9 in)
2019
27.5 mm (1.1 in)
2020
27.5 mm (1.1 in)
2021
30.3 mm (1.2 in)
2022
36.9 mm (1.5 in)
2023
42.4 mm (1.7 in)
2024
26.9 mm (1.1 in)
2025
47.3 mm (1.9 in)
2026
19.5 mm (0.8 in)
Longest dry spell (CDD)
The longest dry spell of the year at Arco, 1914 to 2026. The record is 114 days in 1936, marked on the chart; the median year is 44 days.
Longest dry spell (CDD) at Arco by year
Year
Longest dry spell (CDD)
1914
43 days
1915
32 days
1916
38 days
1917
16 days
1920
36 days
1921
99 days
1922
62 days
1923
37 days
1924
54 days
1925
29 days
1926
64 days
1927
26 days
1928
51 days
1929
37 days
1930
34 days
1931
32 days
1932
72 days
1933
75 days
1934
55 days
1935
92 days
1936
114 days
1937
53 days
1938
44 days
1939
60 days
1940
52 days
1941
36 days
1942
71 days
1944
40 days
1945
21 days
1946
21 days
1947
42 days
1948
38 days
1949
50 days
1950
32 days
1951
40 days
1952
63 days
1953
73 days
1954
34 days
1955
37 days
1956
50 days
1957
45 days
1958
57 days
1959
84 days
1960
50 days
1961
37 days
1962
54 days
1963
29 days
1964
40 days
1965
45 days
1966
50 days
1967
62 days
1968
27 days
1969
31 days
1970
33 days
1971
33 days
1972
61 days
1973
38 days
1974
50 days
1975
23 days
1976
89 days
1977
59 days
1978
54 days
1979
29 days
1980
41 days
1981
44 days
1982
25 days
1983
19 days
1984
41 days
1985
32 days
1986
26 days
1987
65 days
1988
65 days
1989
28 days
1990
42 days
1991
61 days
1992
60 days
1993
30 days
1994
73 days
1995
17 days
1996
62 days
1997
80 days
1998
34 days
1999
64 days
2000
28 days
2001
43 days
2002
50 days
2003
63 days
2004
51 days
2005
71 days
2006
51 days
2007
57 days
2008
42 days
2009
29 days
2010
25 days
2011
48 days
2012
27 days
2013
58 days
2014
42 days
2015
36 days
2016
80 days
2017
44 days
2018
45 days
2019
39 days
2020
29 days
2021
41 days
2022
51 days
2023
55 days
2024
61 days
2025
39 days
2026
43 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
57 years with a frost
Across 57 years with a frost, the median last spring frost at Arco falls on 5 June and the median first autumn frost on 11 September, which leaves a median of 99 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 Arco
Measure
Median, all years
Earliest period
Recent period (1971 to 2025)
Recent against earliest
Fitted trend
Last spring frost
5 June
n/a
2 June
n/a
-1.7 days per decade
First autumn frost
11 September
n/a
15 September
n/a
+2.2 days per decade
Growing days
99 days
n/a
105 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
72 years, 1915 to 2025
A day with at least 21.2 mm (0.8 in) of rain is expected about once in 2 years. A day with at least 50.6 mm (2.0 in) of rain is expected about once in 100 years.
Rainfall return levels at Arco: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
21.2 mm (0.8 in)
5 years
28.2 mm (1.1 in)
10 years
33.2 mm (1.3 in)
25 years
39.9 mm (1.6 in)
50 years
45.1 mm (1.8 in)
100 years
50.6 mm (2.0 in)
Longer than the 72 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, 72 years of values from 1915 to 2025.
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: 62.0 mm (2.4 in) in 1985; 48.0 mm (1.9 in) in 1962; 41.9 mm (1.6 in) in 2011.
Station Changes
No change in the annual mean temperature of this station was found against its neighbours.
Climate Twins
2003 to 2025 against 1961 to 1990
Over 2003 to 2025, Arco had a mean temperature of 6.6 C (43.9 F) and 221.5 mm (8.7 in) of rain a year. The 3 stations whose 1961 to 1990 climate was closest to that are Neola (United States, 447 km away), Idaho Falls FAA AP (United States, 100 km away) and Altamont (United States, 440 km away).
Climate twins of Arco: stations whose 1961 to 1990 climate is closest to its 2003 to 2025 climate
Twins are stations, not cities. A twin is one of the three stations at least 100 km away whose earlier climate is closest to this station's recent one, so a close match does not mean the two places look alike in other ways. A station move or a gap in a record can change that station's averages. The list describes past climate; it is not a forecast and does not say what caused any change. How twins are found, and a search for any station.
Download the Data
Data for Arco standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Arco 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.