Otter 9 SSW Weather Records (USC00246287)

Record envelope, standing records and threshold days for Otter 9 SSW (USC00246287), Montana, United States, with 30 years of record.

Key Facts for Otter 9 SSW

Otter 9 SSW (USC00246287) is a weather station in Montana, United States at 45.10 latitude and -106.25 longitude, 1,238 m (4,060 ft) above sea level.
The station reports from 1961 to 1990, 30 years of record.
1,464 records set at Otter 9 SSW still stand.
Records are tracked for no element yet: an element needs 30 years of data to be eligible.

About the Station

Location: Montana, United States, 45.10 latitude, -106.25 longitude.
Elevation: 1,238 m (4,060 ft).
Period of record: 1961 to 1990, 30 years.
Eligible elements: none yet.

Daily Record Envelope and 2026

0 days at or beyond a record

The band shows the record high and record low for each calendar day at Otter 9 SSW. 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 Otter 9 SSW, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	16.7 C (62.1 F)	-35.0 C (-31.0 F)	n/a	n/a
Feb	20.0 C (68.0 F)	-37.2 C (-35.0 F)	n/a	n/a
Mar	25.6 C (78.1 F)	-30.0 C (-22.0 F)	n/a	n/a
Apr	30.6 C (87.1 F)	-14.4 C (6.1 F)	n/a	n/a
May	35.6 C (96.1 F)	-8.3 C (17.1 F)	n/a	n/a
Jun	43.3 C (109.9 F)	-1.1 C (30.0 F)	n/a	n/a
Jul	41.1 C (106.0 F)	3.3 C (37.9 F)	n/a	n/a
Aug	40.0 C (104.0 F)	1.7 C (35.1 F)	n/a	n/a
Sep	38.9 C (102.0 F)	-10.0 C (14.0 F)	n/a	n/a
Oct	32.2 C (90.0 F)	-16.7 C (1.9 F)	n/a	n/a
Nov	23.9 C (75.0 F)	-26.1 C (-15.0 F)	n/a	n/a
Dec	16.7 C (62.1 F)	-43.3 C (-45.9 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Otter 9 SSW still stand. 1965 holds the most, with 74.

Standing records at Otter 9 SSW by the year they were set
Year set	Standing records
1961	14
1962	68
1963	61
1964	46
1965	74
1966	66
1967	50
1968	48
1969	70
1970	36
1971	42
1972	62
1973	35
1974	32
1975	43
1976	38
1977	36
1978	59
1979	36
1980	56
1981	50
1982	42
1983	70
1984	40
1985	52
1986	44
1987	65
1988	67
1989	55
1990	7

Wettest Day of Each Month

Apr: 81.3 mm (3.2 in)

The wettest day on record for each calendar month at Otter 9 SSW. The most was 81.3 mm (3.2 in) on 30 April 1967.

Record daily precipitation for each month at Otter 9 SSW
Month	Record daily precipitation (mm)	Date
Jan	20.8 mm (0.8 in)	29 January 1965
Feb	20.3 mm (0.8 in)	19 February 1986
Mar	35.6 mm (1.4 in)	29 March 1977
Apr	81.3 mm (3.2 in)	30 April 1967
May	67.3 mm (2.6 in)	18 May 1978
Jun	56.4 mm (2.2 in)	15 June 1980
Jul	46.5 mm (1.8 in)	25 July 1982
Aug	53.8 mm (2.1 in)	30 August 1971
Sep	59.4 mm (2.3 in)	13 September 1966
Oct	44.5 mm (1.8 in)	2 October 1971
Nov	50.8 mm (2.0 in)	14 November 1964
Dec	16.3 mm (0.6 in)	18 December 1973

Period of Record Coverage

1961 to 1990

30 years of record at Otter 9 SSW, 1961 to 1990. 4 years have data for under 90 percent of days and are left out of rankings: 1961, 1982, 1985, 1990.

Days with data per year at Otter 9 SSW
Year	Days with data	Share of year	Complete
1961	91	25%	No
1962	361	99%	Yes
1963	365	100%	Yes
1964	362	99%	Yes
1965	363	99%	Yes
1966	363	99%	Yes
1967	361	99%	Yes
1968	365	100%	Yes
1969	357	98%	Yes
1970	350	96%	Yes
1971	341	93%	Yes
1972	362	99%	Yes
1973	364	100%	Yes
1974	350	96%	Yes
1975	347	95%	Yes
1976	353	96%	Yes
1977	363	99%	Yes
1978	358	98%	Yes
1979	346	95%	Yes
1980	361	99%	Yes
1981	347	95%	Yes
1982	315	86%	No
1983	332	91%	Yes
1984	341	93%	Yes
1985	313	86%	No
1986	338	93%	Yes
1987	340	93%	Yes
1988	344	94%	Yes
1989	331	91%	Yes
1990	26	7%	No

Latest Records

No records were set at this station in the latest data.

Climate Trend

24 complete years, 1962 to 1989

One stripe for each of 24 complete years at Otter 9 SSW, 1962 to 1989. Blue stripes are years cooler than the station's own mean of 8.1 C (46.5 F); red stripes are warmer. The coolest year was 1978, at 6.2 C (43.2 F), and the warmest was 1988, at 10.2 C (50.3 F). The strongest colour marks a difference of 2.1 C (3.8 F).

Annual mean temperature at Otter 9 SSW as warming stripes, 1962 to 1989
Year	Annual mean temperature	Difference from the station mean
1962	8.2 C	+0.17 C
1963	8.9 C	+0.84 C
1964	7.5 C	-0.55 C
1965	7.2 C	-0.85 C
1966	8.2 C	+0.12 C
1967	7.6 C	-0.42 C
1968	7.3 C	-0.78 C
1969	7.3 C	-0.80 C
1970	7.1 C	-0.93 C
1972	6.7 C	-1.41 C
1974	8.5 C	+0.40 C
1975	6.8 C	-1.24 C
1977	8.1 C	+0.07 C
1978	6.2 C	-1.84 C
1979	7.3 C	-0.80 C
1980	8.9 C	+0.84 C
1981	9.9 C	+1.80 C
1982	7.4 C	-0.64 C
1983	8.9 C	+0.87 C
1984	8.4 C	+0.29 C
1986	9.2 C	+1.10 C
1987	9.7 C	+1.64 C
1988	10.2 C	+2.09 C
1989	8.2 C	+0.12 C

This station does not have enough complete years (30 are needed) to fit a temperature trend.

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

1961 to 1990

Yearly extremes at Otter 9 SSW: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	43.3 C (109.9 F)	1966	38.1 C (100.5 F)	30
Coldest night (TNn)	-43.3 C (-45.9 F)	1983	-29.4 C (-21.0 F)	30
Wettest day (Rx1day)	81.3 mm (3.2 in)	1967	40.3 mm (1.6 in)	30
Wettest five days (Rx5day)	137.2 mm (5.4 in)	1978	59.6 mm (2.3 in)	30
Longest dry spell (CDD)	45 days	1973	24 days	30

Hottest day (TXx)

The hottest day of the year at Otter 9 SSW, 1961 to 1990. The record is 43.3 C (109.9 F) in 1966, marked on the chart; the median year is 38.1 C (100.5 F).

Hottest day (TXx) at Otter 9 SSW by year
Year	Hottest day (TXx)
1961	26.7 C (80.1 F)
1962	36.7 C (98.1 F)
1963	37.8 C (100.0 F)
1964	39.4 C (102.9 F)
1965	38.9 C (102.0 F)
1966	43.3 C (109.9 F)
1967	36.1 C (97.0 F)
1968	35.6 C (96.1 F)
1969	38.9 C (102.0 F)
1970	38.9 C (102.0 F)
1971	37.8 C (100.0 F)
1972	37.8 C (100.0 F)
1973	37.2 C (99.0 F)
1974	36.7 C (98.1 F)
1975	38.3 C (100.9 F)
1976	37.2 C (99.0 F)
1977	39.4 C (102.9 F)
1978	38.9 C (102.0 F)
1979	37.8 C (100.0 F)
1980	41.1 C (106.0 F)
1981	40.0 C (104.0 F)
1982	38.3 C (100.9 F)
1983	41.1 C (106.0 F)
1984	37.8 C (100.0 F)
1985	40.0 C (104.0 F)
1986	37.8 C (100.0 F)
1987	35.6 C (96.1 F)
1988	40.6 C (105.1 F)
1989	41.1 C (106.0 F)
1990	9.4 C (48.9 F)

Coldest night (TNn)

The coldest night of the year at Otter 9 SSW, 1961 to 1990. The record is -43.3 C (-45.9 F) in 1983, marked on the chart; the median year is -29.4 C (-21.0 F).

Coldest night (TNn) at Otter 9 SSW by year
Year	Coldest night (TNn)
1961	-24.4 C (-11.9 F)
1962	-28.9 C (-20.0 F)
1963	-33.9 C (-29.0 F)
1964	-35.6 C (-32.1 F)
1965	-27.8 C (-18.0 F)
1966	-28.3 C (-18.9 F)
1967	-26.7 C (-16.1 F)
1968	-32.2 C (-26.0 F)
1969	-30.0 C (-22.0 F)
1970	-26.1 C (-15.0 F)
1971	-27.8 C (-18.0 F)
1972	-35.0 C (-31.0 F)
1973	-30.0 C (-22.0 F)
1974	-28.9 C (-20.0 F)
1975	-25.0 C (-13.0 F)
1976	-27.8 C (-18.0 F)
1977	-32.8 C (-27.0 F)
1978	-30.0 C (-22.0 F)
1979	-31.1 C (-24.0 F)
1980	-28.3 C (-18.9 F)
1981	-30.6 C (-23.1 F)
1982	-30.6 C (-23.1 F)
1983	-43.3 C (-45.9 F)
1984	-27.8 C (-18.0 F)
1985	-30.0 C (-22.0 F)
1986	-26.1 C (-15.0 F)
1987	-22.8 C (-9.0 F)
1988	-25.6 C (-14.1 F)
1989	-37.2 C (-35.0 F)
1990	-30.0 C (-22.0 F)

Wettest day (Rx1day)

The wettest day of the year at Otter 9 SSW, 1961 to 1990. The record is 81.3 mm (3.2 in) in 1967, marked on the chart; the median year is 40.3 mm (1.6 in).

Wettest day (Rx1day) at Otter 9 SSW by year
Year	Wettest day (Rx1day)
1961	14.0 mm (0.6 in)
1962	26.2 mm (1.0 in)
1963	50.5 mm (2.0 in)
1964	50.8 mm (2.0 in)
1965	31.2 mm (1.2 in)
1966	59.4 mm (2.3 in)
1967	81.3 mm (3.2 in)
1968	41.1 mm (1.6 in)
1969	59.7 mm (2.4 in)
1970	39.4 mm (1.6 in)
1971	53.8 mm (2.1 in)
1972	38.4 mm (1.5 in)
1973	55.6 mm (2.2 in)
1974	32.3 mm (1.3 in)
1975	47.0 mm (1.9 in)
1976	38.9 mm (1.5 in)
1977	46.2 mm (1.8 in)
1978	67.3 mm (2.6 in)
1979	20.6 mm (0.8 in)
1980	56.4 mm (2.2 in)
1981	38.1 mm (1.5 in)
1982	46.5 mm (1.8 in)
1983	20.6 mm (0.8 in)
1984	38.1 mm (1.5 in)
1985	33.5 mm (1.3 in)
1986	43.2 mm (1.7 in)
1987	30.5 mm (1.2 in)
1988	43.2 mm (1.7 in)
1989	25.4 mm (1.0 in)
1990	3.6 mm (0.14 in)

Wettest five days (Rx5day)

The wettest five days of the year at Otter 9 SSW, 1961 to 1990. The record is 137.2 mm (5.4 in) in 1978, marked on the chart; the median year is 59.6 mm (2.3 in).

Wettest five days (Rx5day) at Otter 9 SSW by year
Year	Wettest five days (Rx5day)
1961	31.5 mm (1.2 in)
1962	52.4 mm (2.1 in)
1963	62.5 mm (2.5 in)
1964	85.6 mm (3.4 in)
1965	42.9 mm (1.7 in)
1966	59.7 mm (2.4 in)
1967	96.0 mm (3.8 in)
1968	59.4 mm (2.3 in)
1969	99.3 mm (3.9 in)
1970	49.8 mm (2.0 in)
1971	76.8 mm (3.0 in)
1972	43.9 mm (1.7 in)
1973	104.6 mm (4.1 in)
1974	47.5 mm (1.9 in)
1975	58.7 mm (2.3 in)
1976	78.8 mm (3.1 in)
1977	68.1 mm (2.7 in)
1978	137.2 mm (5.4 in)
1979	29.6 mm (1.2 in)
1980	69.1 mm (2.7 in)
1981	52.8 mm (2.1 in)
1982	49.0 mm (1.9 in)
1983	44.1 mm (1.7 in)
1984	74.9 mm (2.9 in)
1985	59.9 mm (2.4 in)
1986	76.2 mm (3.0 in)
1987	62.3 mm (2.5 in)
1988	57.2 mm (2.3 in)
1989	41.2 mm (1.6 in)
1990	6.6 mm (0.26 in)

Longest dry spell (CDD)

The longest dry spell of the year at Otter 9 SSW, 1961 to 1990. The record is 45 days in 1973, marked on the chart; the median year is 24 days.

Longest dry spell (CDD) at Otter 9 SSW by year
Year	Longest dry spell (CDD)
1961	17 days
1962	21 days
1963	32 days
1964	32 days
1965	42 days
1966	22 days
1967	33 days
1968	20 days
1969	35 days
1970	24 days
1971	21 days
1972	20 days
1973	45 days
1974	24 days
1975	23 days
1976	26 days
1977	22 days
1978	33 days
1979	19 days
1980	19 days
1981	25 days
1982	19 days
1983	33 days
1984	16 days
1985	25 days
1986	26 days
1987	23 days
1988	33 days
1989	21 days
1990	17 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

24 years with a frost

Across 24 years with a frost, the median last spring frost at Otter 9 SSW falls on 14 May and the median first autumn frost on 21 September, which leaves a median of 133 days between them.

Frost dates and growing season at Otter 9 SSW
Measure	Median, all years	Earliest period	Recent period (1962 to 1989)	Recent against earliest	Fitted trend
Last spring frost	14 May	n/a	14 May	n/a	n/a
First autumn frost	21 September	n/a	21 September	n/a	n/a
Growing days	133 days	n/a	133 days	n/a	n/a

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.

Download the Data

Data for Otter 9 SSW standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Otter 9 SSW 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.

Data as of 2025-12-31. Last revised 31 December 2025 (2025-12-31).