Record envelope, standing records and threshold days for Portland 1 SW (USC00127069), Indiana, United States, with 81 years of record.
Key Facts for Portland 1 SW
Portland 1 SW (USC00127069) is a weather station in Indiana, United States at 40.42 latitude and -84.99 longitude, 277 m (910 ft) above sea level.
The station reports from 1946 to 2026, 81 years of record.
1,464 records set at Portland 1 SW still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Portland 1 SW set a daily record precipitation of 45.7 mm (1.8 in) on 13 August 2026.
About the Station
Location: Indiana, United States, 40.42 latitude, -84.99 longitude.
Elevation: 277 m (910 ft).
Period of record: 1946 to 2026, 81 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
11 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 Portland 1 SW. The lines show the 2026 daily maximum and minimum. 11 days in 2026 matched or passed a record. Temperatures are in degrees Celsius.
Daily record high and record low at Portland 1 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)
-33.9 C (-29.0 F)
16.1 C (61.0 F)
-23.3 C (-9.9 F)
Feb
22.8 C (73.0 F)
-26.7 C (-16.1 F)
20.0 C (68.0 F)
-22.2 C (-8.0 F)
Mar
29.4 C (84.9 F)
-25.0 C (-13.0 F)
28.3 C (82.9 F)
-8.9 C (16.0 F)
Apr
30.6 C (87.1 F)
-12.2 C (10.0 F)
28.3 C (82.9 F)
-2.2 C (28.0 F)
May
33.3 C (91.9 F)
-3.3 C (26.1 F)
30.0 C (86.0 F)
0.0 C (32.0 F)
Jun
40.0 C (104.0 F)
3.3 C (37.9 F)
32.2 C (90.0 F)
7.8 C (46.0 F)
Jul
38.9 C (102.0 F)
4.4 C (39.9 F)
34.4 C (93.9 F)
10.6 C (51.1 F)
Aug
37.8 C (100.0 F)
3.3 C (37.9 F)
31.7 C (89.1 F)
10.0 C (50.0 F)
Sep
35.6 C (96.1 F)
-2.2 C (28.0 F)
n/a
n/a
Oct
32.8 C (91.0 F)
-8.3 C (17.1 F)
n/a
n/a
Nov
26.1 C (79.0 F)
-16.1 C (3.0 F)
n/a
n/a
Dec
22.2 C (72.0 F)
-29.4 C (-20.9 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Portland 1 SW still stand. 1988 holds the most, with 58.
Standing records at Portland 1 SW by the year they were set
Year set
Standing records
1964
28
1970
6
1971
2
1973
9
1974
17
1976
35
1977
54
1978
30
1979
41
1980
28
1981
14
1982
35
1983
50
1984
28
1985
36
1986
41
1987
22
1988
58
1989
35
1990
44
1991
55
1992
22
1993
23
1994
27
1995
24
1996
28
1997
32
1998
32
1999
36
2000
26
2001
21
2002
18
2003
9
2004
21
2005
13
2006
5
2007
18
2008
11
2009
5
2010
21
2011
33
2012
41
2013
11
2014
44
2015
27
2016
22
2017
30
2018
28
2019
39
2020
15
2021
21
2022
11
2023
18
2024
30
2025
16
2026
18
All-Time Record Progression
7 new records
7 all-time records were set at Portland 1 SW between 4 February 1982 and 14 July 2015. Each dot is a new record.
When Portland 1 SW set new all-time records
Date
Kind
Detail
1982-02-04
Record snow depth
Record snow depth 50.8 cm (20.0 in)
1982-02-09
Record snow depth
Record snow depth 55.9 cm (22.0 in)
2007-01-22
Record daily snowfall
Record daily snowfall 26.7 cm (10.5 in)
2007-02-14
Record daily snowfall
Record daily snowfall 35.6 cm (14.0 in)
2012-06-29
Record high maximum temperature
Record high maximum temperature 40.0 C (104.0 F)
2013-07-15
Record high minimum temperature
Record high minimum temperature 26.7 C (80.1 F)
2015-07-14
Record daily precipitation
Record daily precipitation 109.2 mm (4.3 in)
Wettest Day of Each Month
Jul: 109.2 mm (4.3 in)
The wettest day on record for each calendar month at Portland 1 SW. The most was 109.2 mm (4.3 in) on 14 July 2015.
Record daily precipitation for each month at Portland 1 SW
Month
Record daily precipitation (mm)
Date
Jan
78.7 mm (3.1 in)
12 January 2005
Feb
69.1 mm (2.7 in)
28 February 2011
Mar
59.7 mm (2.4 in)
11 March 1952
Apr
83.1 mm (3.3 in)
11 April 2013
May
82.3 mm (3.2 in)
27 May 1946
Jun
106.4 mm (4.2 in)
8 June 1958
Jul
109.2 mm (4.3 in)
14 July 2015
Aug
101.6 mm (4.0 in)
5 August 1998
Sep
76.2 mm (3.0 in)
17 September 1969
Oct
74.2 mm (2.9 in)
25 October 2021
Nov
55.9 mm (2.2 in)
14 November 1951
Dec
78.7 mm (3.1 in)
22 December 2013
Period of Record Coverage
1964 to 2026
Complete yearUnder 90 percent of days
56 years of record at Portland 1 SW, 1964 to 2026. 14 years have data for under 90 percent of days and are left out of rankings: 1964, 1970, 1971, 1973, 1974, 1976, 2002, 2005 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 38 complete years at Portland 1 SW, 1977 to 2025. Blue stripes are years cooler than the station's own mean of 10.1 C (50.3 F); red stripes are warmer. The coolest year was 1978, at 8.4 C (47.0 F), and the warmest was 2024, at 11.8 C (53.3 F). The strongest colour marks a difference of 1.8 C (3.2 F).
Annual mean temperature at Portland 1 SW as warming stripes, 1977 to 2025
Year
Annual mean temperature
Difference from the station mean
1977
9.6 C
-0.59 C
1978
8.4 C
-1.78 C
1979
8.6 C
-1.55 C
1980
9.4 C
-0.75 C
1981
9.8 C
-0.38 C
1983
10.2 C
+0.04 C
1984
9.8 C
-0.34 C
1985
9.8 C
-0.39 C
1986
10.4 C
+0.22 C
1987
11.0 C
+0.86 C
1988
9.8 C
-0.39 C
1989
9.2 C
-0.97 C
1990
10.9 C
+0.80 C
1991
11.1 C
+0.94 C
1992
9.7 C
-0.48 C
1993
9.5 C
-0.64 C
1994
9.8 C
-0.36 C
1995
9.7 C
-0.49 C
1996
9.0 C
-1.10 C
1997
9.3 C
-0.84 C
1999
10.6 C
+0.41 C
2000
9.9 C
-0.20 C
2001
11.0 C
+0.83 C
2010
10.4 C
+0.26 C
2011
10.7 C
+0.58 C
2012
11.6 C
+1.46 C
2013
10.1 C
+0.00 C
2014
8.5 C
-1.61 C
2015
10.1 C
-0.09 C
2016
11.3 C
+1.19 C
2017
10.9 C
+0.80 C
2018
10.2 C
+0.10 C
2020
10.8 C
+0.66 C
2021
11.0 C
+0.82 C
2022
10.0 C
-0.12 C
2023
11.2 C
+1.06 C
2024
11.8 C
+1.70 C
2025
10.4 C
+0.30 C
The annual mean temperature here has risen by 0.3 C (0.1 to 0.5) per decade over 1977 to 2025. In Fahrenheit: 0.5 F (0.2 to 0.8) per decade. The slope is a straight line fitted to 38 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at Portland 1 SW
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
0.3 C (0.1 to 0.5) per decade
0.5 F (0.2 to 0.8) per decade
1977 to 2025
38
Rise
Mean daily maximum
0.3 C (0.2 to 0.5) per decade
0.6 F (0.3 to 0.9) per decade
1977 to 2025
38
Rise
Mean daily minimum
0.3 C (0.1 to 0.4) per decade
0.5 F (0.2 to 0.7) per decade
1977 to 2025
38
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
1946 to 2026
Yearly extremes at Portland 1 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)
2012
34.4 C (93.9 F)
56
Coldest night (TNn)
-33.9 C (-29.0 F)
1985
-22.8 C (-9.0 F)
56
Wettest day (Rx1day)
109.2 mm (4.3 in)
2015
55.6 mm (2.2 in)
81
Wettest five days (Rx5day)
180.8 mm (7.1 in)
1958
86.1 mm (3.4 in)
81
Longest dry spell (CDD)
66 days
1963
18 days
81
Hottest day (TXx)
The hottest day of the year at Portland 1 SW, 1946 to 2026. The record is 40.0 C (104.0 F) in 2012, marked on the chart; the median year is 34.4 C (93.9 F).
Hottest day (TXx) at Portland 1 SW by year
Year
Hottest day (TXx)
1946
n/a
1947
n/a
1948
n/a
1949
n/a
1950
n/a
1951
n/a
1952
n/a
1953
n/a
1954
n/a
1955
n/a
1956
n/a
1957
n/a
1958
n/a
1959
n/a
1960
n/a
1961
n/a
1962
n/a
1963
n/a
1964
36.7 C (98.1 F)
1965
n/a
1966
n/a
1967
n/a
1968
n/a
1969
n/a
1970
32.2 C (90.0 F)
1971
18.9 C (66.0 F)
1972
n/a
1973
34.4 C (93.9 F)
1974
37.8 C (100.0 F)
1975
n/a
1976
32.8 C (91.0 F)
1977
36.7 C (98.1 F)
1978
33.9 C (93.0 F)
1979
31.7 C (89.1 F)
1980
37.2 C (99.0 F)
1981
33.9 C (93.0 F)
1982
33.3 C (91.9 F)
1983
37.2 C (99.0 F)
1984
35.0 C (95.0 F)
1985
33.3 C (91.9 F)
1986
33.9 C (93.0 F)
1987
34.4 C (93.9 F)
1988
38.9 C (102.0 F)
1989
35.0 C (95.0 F)
1990
35.6 C (96.1 F)
1991
35.6 C (96.1 F)
1992
32.2 C (90.0 F)
1993
33.9 C (93.0 F)
1994
35.6 C (96.1 F)
1995
36.1 C (97.0 F)
1996
34.4 C (93.9 F)
1997
34.4 C (93.9 F)
1998
34.4 C (93.9 F)
1999
37.2 C (99.0 F)
2000
32.2 C (90.0 F)
2001
33.3 C (91.9 F)
2002
35.0 C (95.0 F)
2003
32.2 C (90.0 F)
2004
32.8 C (91.0 F)
2005
35.0 C (95.0 F)
2006
25.6 C (78.1 F)
2007
35.0 C (95.0 F)
2008
34.4 C (93.9 F)
2009
33.9 C (93.0 F)
2010
34.4 C (93.9 F)
2011
37.8 C (100.0 F)
2012
40.0 C (104.0 F)
2013
35.6 C (96.1 F)
2014
33.3 C (91.9 F)
2015
33.3 C (91.9 F)
2016
32.8 C (91.0 F)
2017
33.3 C (91.9 F)
2018
33.3 C (91.9 F)
2019
33.9 C (93.0 F)
2020
33.3 C (91.9 F)
2021
33.3 C (91.9 F)
2022
35.0 C (95.0 F)
2023
33.3 C (91.9 F)
2024
35.6 C (96.1 F)
2025
34.4 C (93.9 F)
2026
34.4 C (93.9 F)
Coldest night (TNn)
The coldest night of the year at Portland 1 SW, 1946 to 2026. The record is -33.9 C (-29.0 F) in 1985, marked on the chart; the median year is -22.8 C (-9.0 F).
Coldest night (TNn) at Portland 1 SW by year
Year
Coldest night (TNn)
1946
n/a
1947
n/a
1948
n/a
1949
n/a
1950
n/a
1951
n/a
1952
n/a
1953
n/a
1954
n/a
1955
n/a
1956
n/a
1957
n/a
1958
n/a
1959
n/a
1960
n/a
1961
n/a
1962
n/a
1963
n/a
1964
-11.1 C (12.0 F)
1965
n/a
1966
n/a
1967
n/a
1968
n/a
1969
n/a
1970
0.0 C (32.0 F)
1971
-12.8 C (9.0 F)
1972
n/a
1973
-1.1 C (30.0 F)
1974
-18.9 C (-2.0 F)
1975
n/a
1976
-23.9 C (-11.0 F)
1977
-28.9 C (-20.0 F)
1978
-26.7 C (-16.1 F)
1979
-26.1 C (-15.0 F)
1980
-23.3 C (-9.9 F)
1981
-23.3 C (-9.9 F)
1982
-27.8 C (-18.0 F)
1983
-28.9 C (-20.0 F)
1984
-30.0 C (-22.0 F)
1985
-33.9 C (-29.0 F)
1986
-19.4 C (-2.9 F)
1987
-21.1 C (-6.0 F)
1988
-21.1 C (-6.0 F)
1989
-29.4 C (-20.9 F)
1990
-18.9 C (-2.0 F)
1991
-17.8 C (0.0 F)
1992
-22.8 C (-9.0 F)
1993
-22.8 C (-9.0 F)
1994
-31.1 C (-24.0 F)
1995
-20.0 C (-4.0 F)
1996
-24.4 C (-11.9 F)
1997
-21.7 C (-7.1 F)
1998
-14.4 C (6.1 F)
1999
-23.9 C (-11.0 F)
2000
-26.7 C (-16.1 F)
2001
-16.7 C (1.9 F)
2002
-16.1 C (3.0 F)
2003
-25.6 C (-14.1 F)
2004
-26.7 C (-16.1 F)
2005
-19.4 C (-2.9 F)
2006
-16.1 C (3.0 F)
2007
-21.7 C (-7.1 F)
2008
-21.1 C (-6.0 F)
2009
-26.1 C (-15.0 F)
2010
-24.4 C (-11.9 F)
2011
-22.8 C (-9.0 F)
2012
-18.9 C (-2.0 F)
2013
-16.7 C (1.9 F)
2014
-27.2 C (-17.0 F)
2015
-23.3 C (-9.9 F)
2016
-20.0 C (-4.0 F)
2017
-21.1 C (-6.0 F)
2018
-26.1 C (-15.0 F)
2019
-25.6 C (-14.1 F)
2020
-16.7 C (1.9 F)
2021
-22.8 C (-9.0 F)
2022
-22.8 C (-9.0 F)
2023
-13.9 C (7.0 F)
2024
-21.1 C (-6.0 F)
2025
-21.1 C (-6.0 F)
2026
-23.3 C (-9.9 F)
Wettest day (Rx1day)
The wettest day of the year at Portland 1 SW, 1946 to 2026. The record is 109.2 mm (4.3 in) in 2015, marked on the chart; the median year is 55.6 mm (2.2 in).
Wettest day (Rx1day) at Portland 1 SW by year
Year
Wettest day (Rx1day)
1946
82.3 mm (3.2 in)
1947
39.1 mm (1.5 in)
1948
75.7 mm (3.0 in)
1949
38.1 mm (1.5 in)
1950
63.5 mm (2.5 in)
1951
55.9 mm (2.2 in)
1952
75.7 mm (3.0 in)
1953
53.3 mm (2.1 in)
1954
38.1 mm (1.5 in)
1955
38.9 mm (1.5 in)
1956
61.5 mm (2.4 in)
1957
94.7 mm (3.7 in)
1958
106.4 mm (4.2 in)
1959
68.1 mm (2.7 in)
1960
61.7 mm (2.4 in)
1961
49.8 mm (2.0 in)
1962
63.5 mm (2.5 in)
1963
63.0 mm (2.5 in)
1964
43.2 mm (1.7 in)
1965
49.0 mm (1.9 in)
1966
40.6 mm (1.6 in)
1967
58.4 mm (2.3 in)
1968
48.3 mm (1.9 in)
1969
76.2 mm (3.0 in)
1970
50.8 mm (2.0 in)
1971
52.1 mm (2.1 in)
1972
69.9 mm (2.8 in)
1973
39.9 mm (1.6 in)
1974
57.2 mm (2.3 in)
1975
46.5 mm (1.8 in)
1976
29.5 mm (1.2 in)
1977
55.6 mm (2.2 in)
1978
41.4 mm (1.6 in)
1979
53.3 mm (2.1 in)
1980
45.2 mm (1.8 in)
1981
53.3 mm (2.1 in)
1982
42.7 mm (1.7 in)
1983
50.3 mm (2.0 in)
1984
57.2 mm (2.3 in)
1985
42.4 mm (1.7 in)
1986
46.2 mm (1.8 in)
1987
41.1 mm (1.6 in)
1988
54.6 mm (2.1 in)
1989
74.9 mm (2.9 in)
1990
79.0 mm (3.1 in)
1991
46.7 mm (1.8 in)
1992
62.7 mm (2.5 in)
1993
77.0 mm (3.0 in)
1994
62.2 mm (2.4 in)
1995
39.4 mm (1.6 in)
1996
43.2 mm (1.7 in)
1997
63.5 mm (2.5 in)
1998
101.6 mm (4.0 in)
1999
30.7 mm (1.2 in)
2000
41.7 mm (1.6 in)
2001
73.2 mm (2.9 in)
2002
42.4 mm (1.7 in)
2003
55.4 mm (2.2 in)
2004
76.2 mm (3.0 in)
2005
78.7 mm (3.1 in)
2006
50.0 mm (2.0 in)
2007
43.2 mm (1.7 in)
2008
37.8 mm (1.5 in)
2009
64.0 mm (2.5 in)
2010
73.7 mm (2.9 in)
2011
69.1 mm (2.7 in)
2012
86.9 mm (3.4 in)
2013
83.1 mm (3.3 in)
2014
98.0 mm (3.9 in)
2015
109.2 mm (4.3 in)
2016
62.2 mm (2.4 in)
2017
61.0 mm (2.4 in)
2018
46.5 mm (1.8 in)
2019
70.6 mm (2.8 in)
2020
74.9 mm (2.9 in)
2021
74.2 mm (2.9 in)
2022
39.1 mm (1.5 in)
2023
39.9 mm (1.6 in)
2024
41.1 mm (1.6 in)
2025
50.8 mm (2.0 in)
2026
66.0 mm (2.6 in)
Wettest five days (Rx5day)
The wettest five days of the year at Portland 1 SW, 1946 to 2026. The record is 180.8 mm (7.1 in) in 1958, marked on the chart; the median year is 86.1 mm (3.4 in).
Wettest five days (Rx5day) at Portland 1 SW by year
Year
Wettest five days (Rx5day)
1946
99.7 mm (3.9 in)
1947
68.0 mm (2.7 in)
1948
98.6 mm (3.9 in)
1949
56.9 mm (2.2 in)
1950
128.3 mm (5.1 in)
1951
65.6 mm (2.6 in)
1952
109.2 mm (4.3 in)
1953
66.4 mm (2.6 in)
1954
90.2 mm (3.6 in)
1955
58.7 mm (2.3 in)
1956
79.6 mm (3.1 in)
1957
133.3 mm (5.2 in)
1958
180.8 mm (7.1 in)
1959
105.4 mm (4.1 in)
1960
70.8 mm (2.8 in)
1961
104.1 mm (4.1 in)
1962
65.0 mm (2.6 in)
1963
70.4 mm (2.8 in)
1964
83.8 mm (3.3 in)
1965
59.9 mm (2.4 in)
1966
107.9 mm (4.2 in)
1967
69.8 mm (2.7 in)
1968
81.3 mm (3.2 in)
1969
113.0 mm (4.4 in)
1970
99.1 mm (3.9 in)
1971
58.9 mm (2.3 in)
1972
99.1 mm (3.9 in)
1973
68.9 mm (2.7 in)
1974
126.7 mm (5.0 in)
1975
66.2 mm (2.6 in)
1976
56.3 mm (2.2 in)
1977
88.4 mm (3.5 in)
1978
68.9 mm (2.7 in)
1979
82.8 mm (3.3 in)
1980
115.8 mm (4.6 in)
1981
78.3 mm (3.1 in)
1982
69.4 mm (2.7 in)
1983
72.9 mm (2.9 in)
1984
61.3 mm (2.4 in)
1985
97.8 mm (3.9 in)
1986
62.4 mm (2.5 in)
1987
86.1 mm (3.4 in)
1988
112.2 mm (4.4 in)
1989
110.7 mm (4.4 in)
1990
134.9 mm (5.3 in)
1991
86.6 mm (3.4 in)
1992
138.4 mm (5.4 in)
1993
126.0 mm (5.0 in)
1994
91.7 mm (3.6 in)
1995
78.5 mm (3.1 in)
1996
78.2 mm (3.1 in)
1997
80.3 mm (3.2 in)
1998
132.6 mm (5.2 in)
1999
39.8 mm (1.6 in)
2000
70.8 mm (2.8 in)
2001
108.8 mm (4.3 in)
2002
67.5 mm (2.7 in)
2003
172.2 mm (6.8 in)
2004
148.0 mm (5.8 in)
2005
61.7 mm (2.4 in)
2006
50.0 mm (2.0 in)
2007
76.2 mm (3.0 in)
2008
78.2 mm (3.1 in)
2009
78.0 mm (3.1 in)
2010
97.3 mm (3.8 in)
2011
91.4 mm (3.6 in)
2012
102.7 mm (4.0 in)
2013
100.3 mm (3.9 in)
2014
121.4 mm (4.8 in)
2015
141.2 mm (5.6 in)
2016
82.3 mm (3.2 in)
2017
85.6 mm (3.4 in)
2018
99.3 mm (3.9 in)
2019
98.0 mm (3.9 in)
2020
74.9 mm (2.9 in)
2021
86.9 mm (3.4 in)
2022
79.4 mm (3.1 in)
2023
62.0 mm (2.4 in)
2024
95.7 mm (3.8 in)
2025
157.5 mm (6.2 in)
2026
143.0 mm (5.6 in)
Longest dry spell (CDD)
The longest dry spell of the year at Portland 1 SW, 1946 to 2026. The record is 66 days in 1963, marked on the chart; the median year is 18 days.
Longest dry spell (CDD) at Portland 1 SW by year
Year
Longest dry spell (CDD)
1946
19 days
1947
25 days
1948
15 days
1949
21 days
1950
16 days
1951
17 days
1952
18 days
1953
26 days
1954
18 days
1955
16 days
1956
27 days
1957
22 days
1958
22 days
1959
14 days
1960
16 days
1961
18 days
1962
18 days
1963
66 days
1964
27 days
1965
20 days
1966
22 days
1967
15 days
1968
15 days
1969
16 days
1970
11 days
1971
13 days
1972
13 days
1973
17 days
1974
16 days
1975
15 days
1976
25 days
1977
17 days
1978
16 days
1979
14 days
1980
12 days
1981
24 days
1982
14 days
1983
28 days
1984
15 days
1985
13 days
1986
15 days
1987
18 days
1988
19 days
1989
23 days
1990
13 days
1991
15 days
1992
19 days
1993
18 days
1994
14 days
1995
23 days
1996
19 days
1997
15 days
1998
18 days
1999
23 days
2000
20 days
2001
15 days
2002
16 days
2003
16 days
2004
13 days
2005
21 days
2006
18 days
2007
11 days
2008
16 days
2009
32 days
2010
20 days
2011
21 days
2012
21 days
2013
15 days
2014
14 days
2015
26 days
2016
18 days
2017
20 days
2018
14 days
2019
14 days
2020
17 days
2021
11 days
2022
29 days
2023
19 days
2024
20 days
2025
21 days
2026
14 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
38 years with a frost
Across 38 years with a frost, the median last spring frost at Portland 1 SW falls on 28 April and the median first autumn frost on 9 October, which leaves a median of 165 days between them.
Fitted over all years, the growing season changes by +4.4 days per decade at this station.
Frost dates and growing season at Portland 1 SW
Measure
Median, all years
Earliest period
Recent period (1986 to 2025)
Recent against earliest
Fitted trend
Last spring frost
28 April
n/a
27 April
n/a
-0.1 days per decade
First autumn frost
9 October
n/a
16 October
n/a
+4.3 days per decade
Growing days
165 days
n/a
167 days
n/a
+4.4 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
68 years, 1950 to 2025
A day with at least 55.4 mm (2.2 in) of rain is expected about once in 2 years. A day with at least 119.7 mm (4.7 in) of rain is expected about once in 100 years.
Rainfall return levels at Portland 1 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
55.4 mm (2.2 in)
5 years
71.6 mm (2.8 in)
10 years
82.8 mm (3.3 in)
25 years
97.3 mm (3.8 in)
50 years
108.4 mm (4.3 in)
100 years
119.7 mm (4.7 in)
Longer than the 68 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, 68 years of values from 1950 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: 109.2 mm (4.3 in) in 2015; 106.4 mm (4.2 in) in 1958; 101.6 mm (4.0 in) in 1998.
Download the Data
Data for Portland 1 SW standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Portland 1 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.