Grass River Weather Records (CA005041140)

Record envelope, standing records and threshold days for Grass River (CA005041140), Manitoba, Canada, with 40 years of record.

Key Facts for Grass River

Grass River (CA005041140) is a weather station in Manitoba, Canada at 50.52 latitude and -98.97 longitude, 270 m (886 ft) above sea level.
The station reports from 1958 to 1997, 40 years of record.
1,464 records set at Grass River still stand.
Records are tracked for no element yet: an element needs 30 years of data to be eligible.

About the Station

Location: Manitoba, Canada, 50.52 latitude, -98.97 longitude.
Elevation: 270 m (886 ft).
Period of record: 1958 to 1997, 40 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 Grass River. 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 Grass River, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	10.0 C (50.0 F)	-43.3 C (-45.9 F)	n/a	n/a
Feb	12.8 C (55.0 F)	-44.4 C (-47.9 F)	n/a	n/a
Mar	19.4 C (66.9 F)	-44.4 C (-47.9 F)	n/a	n/a
Apr	35.0 C (95.0 F)	-28.9 C (-20.0 F)	n/a	n/a
May	38.5 C (101.3 F)	-10.0 C (14.0 F)	n/a	n/a
Jun	38.3 C (100.9 F)	-2.8 C (27.0 F)	n/a	n/a
Jul	37.8 C (100.0 F)	2.0 C (35.6 F)	n/a	n/a
Aug	38.3 C (100.9 F)	-0.6 C (30.9 F)	n/a	n/a
Sep	38.0 C (100.4 F)	-7.8 C (18.0 F)	n/a	n/a
Oct	30.6 C (87.1 F)	-15.0 C (5.0 F)	n/a	n/a
Nov	20.6 C (69.1 F)	-30.6 C (-23.1 F)	n/a	n/a
Dec	12.2 C (54.0 F)	-41.1 C (-42.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Grass River still stand. 1983 holds the most, with 78.

Standing records at Grass River by the year they were set
Year set	Standing records
1958	68
1959	71
1960	38
1961	62
1962	56
1963	72
1964	59
1965	67
1966	75
1967	64
1968	56
1969	46
1970	42
1971	29
1972	57
1973	57
1974	59
1975	46
1976	48
1977	68
1978	36
1979	51
1980	63
1981	60
1982	36
1983	78

Wettest Day of Each Month

Aug: 96.2 mm (3.8 in)

The wettest day on record for each calendar month at Grass River. The most was 96.2 mm (3.8 in) on 20 August 1980.

Record daily precipitation for each month at Grass River
Month	Record daily precipitation (mm)	Date
Jan	20.0 mm (0.8 in)	10 January 1980
Feb	27.9 mm (1.1 in)	3 February 1962
Mar	35.6 mm (1.4 in)	27 March 1975
Apr	35.6 mm (1.4 in)	27 April 1966
May	67.3 mm (2.6 in)	24 May 1978
Jun	42.9 mm (1.7 in)	30 June 1971
Jul	71.9 mm (2.8 in)	15 July 1965
Aug	96.2 mm (3.8 in)	20 August 1980
Sep	62.2 mm (2.4 in)	12 September 1978
Oct	35.6 mm (1.4 in)	10 October 1959
Nov	20.3 mm (0.8 in)	28 November 1975
Dec	20.3 mm (0.8 in)	30 December 1965

Period of Record Coverage

1958 to 1983

26 years of record at Grass River, 1958 to 1983. 1 years have data for under 90 percent of days and are left out of rankings: 1982.

Days with data per year at Grass River
Year	Days with data	Share of year	Complete
1958	332	91%	Yes
1959	362	99%	Yes
1960	366	100%	Yes
1961	364	100%	Yes
1962	350	96%	Yes
1963	364	100%	Yes
1964	334	91%	Yes
1965	363	99%	Yes
1966	330	90%	Yes
1967	365	100%	Yes
1968	366	100%	Yes
1969	364	100%	Yes
1970	364	100%	Yes
1971	365	100%	Yes
1972	366	100%	Yes
1973	365	100%	Yes
1974	362	99%	Yes
1975	363	99%	Yes
1976	365	100%	Yes
1977	364	100%	Yes
1978	364	100%	Yes
1979	365	100%	Yes
1980	365	100%	Yes
1981	334	92%	Yes
1982	302	83%	No
1983	364	100%	Yes

Latest Records

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

Climate Trend

20 complete years, 1959 to 1983

One stripe for each of 20 complete years at Grass River, 1959 to 1983. Blue stripes are years cooler than the station's own mean of 1.9 C (35.3 F); red stripes are warmer. The coolest year was 1972, at 0.5 C (33.0 F), and the warmest was 1977, at 3.4 C (38.0 F). The strongest colour marks a difference of 1.5 C (2.7 F).

Annual mean temperature at Grass River as warming stripes, 1959 to 1983
Year	Annual mean temperature	Difference from the station mean
1959	1.5 C	-0.35 C
1960	1.7 C	-0.17 C
1961	2.8 C	+0.91 C
1963	2.7 C	+0.85 C
1965	0.8 C	-1.07 C
1967	1.2 C	-0.62 C
1968	2.1 C	+0.19 C
1969	1.5 C	-0.39 C
1970	1.0 C	-0.84 C
1971	1.8 C	-0.02 C
1972	0.5 C	-1.32 C
1973	2.8 C	+0.94 C
1974	1.3 C	-0.60 C
1975	2.2 C	+0.31 C
1976	2.3 C	+0.43 C
1977	3.4 C	+1.50 C
1978	1.4 C	-0.42 C
1979	0.6 C	-1.25 C
1980	2.7 C	+0.85 C
1983	2.9 C	+1.07 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

1958 to 1983

Yearly extremes at Grass River: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	38.5 C (101.3 F)	1980	35.0 C (95.0 F)	26
Coldest night (TNn)	-44.4 C (-47.9 F)	1962	-38.3 C (-36.9 F)	26
Wettest day (Rx1day)	96.2 mm (3.8 in)	1980	35.6 mm (1.4 in)	26
Wettest five days (Rx5day)	126.4 mm (5.0 in)	1980	58.7 mm (2.3 in)	26
Longest dry spell (CDD)	77 days	1959	30 days	26

Hottest day (TXx)

The hottest day of the year at Grass River, 1958 to 1983. The record is 38.5 C (101.3 F) in 1980, marked on the chart; the median year is 35.0 C (95.0 F).

Hottest day (TXx) at Grass River by year
Year	Hottest day (TXx)
1958	35.0 C (95.0 F)
1959	33.9 C (93.0 F)
1960	33.9 C (93.0 F)
1961	38.3 C (100.9 F)
1962	33.3 C (91.9 F)
1963	33.3 C (91.9 F)
1964	35.0 C (95.0 F)
1965	34.4 C (93.9 F)
1966	35.6 C (96.1 F)
1967	36.1 C (97.0 F)
1968	33.9 C (93.0 F)
1969	35.0 C (95.0 F)
1970	35.6 C (96.1 F)
1971	33.3 C (91.9 F)
1972	36.7 C (98.1 F)
1973	33.9 C (93.0 F)
1974	34.4 C (93.9 F)
1975	37.8 C (100.0 F)
1976	37.2 C (99.0 F)
1977	34.4 C (93.9 F)
1978	35.6 C (96.1 F)
1979	38.3 C (100.9 F)
1980	38.5 C (101.3 F)
1981	36.5 C (97.7 F)
1982	32.0 C (89.6 F)
1983	38.0 C (100.4 F)

Coldest night (TNn)

The coldest night of the year at Grass River, 1958 to 1983. The record is -44.4 C (-47.9 F) in 1962, marked on the chart; the median year is -38.3 C (-36.9 F).

Coldest night (TNn) at Grass River by year
Year	Coldest night (TNn)
1958	-40.0 C (-40.0 F)
1959	-38.9 C (-38.0 F)
1960	-33.9 C (-29.0 F)
1961	-37.2 C (-35.0 F)
1962	-44.4 C (-47.9 F)
1963	-37.2 C (-35.0 F)
1964	-37.8 C (-36.0 F)
1965	-38.9 C (-38.0 F)
1966	-44.4 C (-47.9 F)
1967	-41.1 C (-42.0 F)
1968	-43.3 C (-45.9 F)
1969	-35.6 C (-32.1 F)
1970	-40.6 C (-41.1 F)
1971	-38.3 C (-36.9 F)
1972	-41.7 C (-43.1 F)
1973	-38.9 C (-38.0 F)
1974	-42.2 C (-44.0 F)
1975	-35.0 C (-31.0 F)
1976	-37.8 C (-36.0 F)
1977	-38.3 C (-36.9 F)
1978	-37.2 C (-35.0 F)
1979	-38.3 C (-36.9 F)
1980	-37.0 C (-34.6 F)
1981	-33.0 C (-27.4 F)
1982	-40.0 C (-40.0 F)
1983	-36.0 C (-32.8 F)

Wettest day (Rx1day)

The wettest day of the year at Grass River, 1958 to 1983. The record is 96.2 mm (3.8 in) in 1980, marked on the chart; the median year is 35.6 mm (1.4 in).

Wettest day (Rx1day) at Grass River by year
Year	Wettest day (Rx1day)
1958	31.8 mm (1.3 in)
1959	35.6 mm (1.4 in)
1960	29.7 mm (1.2 in)
1961	61.5 mm (2.4 in)
1962	37.1 mm (1.5 in)
1963	33.5 mm (1.3 in)
1964	24.9 mm (1.0 in)
1965	71.9 mm (2.8 in)
1966	35.6 mm (1.4 in)
1967	34.8 mm (1.4 in)
1968	48.8 mm (1.9 in)
1969	35.6 mm (1.4 in)
1970	32.5 mm (1.3 in)
1971	42.9 mm (1.7 in)
1972	41.1 mm (1.6 in)
1973	42.9 mm (1.7 in)
1974	22.9 mm (0.9 in)
1975	57.7 mm (2.3 in)
1976	34.3 mm (1.4 in)
1977	38.9 mm (1.5 in)
1978	67.3 mm (2.6 in)
1979	30.5 mm (1.2 in)
1980	96.2 mm (3.8 in)
1981	58.0 mm (2.3 in)
1982	24.6 mm (1.0 in)
1983	26.0 mm (1.0 in)

Wettest five days (Rx5day)

The wettest five days of the year at Grass River, 1958 to 1983. The record is 126.4 mm (5.0 in) in 1980, marked on the chart; the median year is 58.7 mm (2.3 in).

Wettest five days (Rx5day) at Grass River by year
Year	Wettest five days (Rx5day)
1958	53.1 mm (2.1 in)
1959	84.4 mm (3.3 in)
1960	49.5 mm (1.9 in)
1961	88.2 mm (3.5 in)
1962	44.0 mm (1.7 in)
1963	66.5 mm (2.6 in)
1964	33.0 mm (1.3 in)
1965	82.8 mm (3.3 in)
1966	59.3 mm (2.3 in)
1967	41.2 mm (1.6 in)
1968	61.0 mm (2.4 in)
1969	86.4 mm (3.4 in)
1970	37.8 mm (1.5 in)
1971	80.2 mm (3.2 in)
1972	41.1 mm (1.6 in)
1973	64.1 mm (2.5 in)
1974	37.6 mm (1.5 in)
1975	95.0 mm (3.7 in)
1976	49.0 mm (1.9 in)
1977	61.0 mm (2.4 in)
1978	79.7 mm (3.1 in)
1979	37.9 mm (1.5 in)
1980	126.4 mm (5.0 in)
1981	58.0 mm (2.3 in)
1982	44.8 mm (1.8 in)
1983	45.6 mm (1.8 in)

Longest dry spell (CDD)

The longest dry spell of the year at Grass River, 1958 to 1983. The record is 77 days in 1959, marked on the chart; the median year is 30 days.

Longest dry spell (CDD) at Grass River by year
Year	Longest dry spell (CDD)
1958	19 days
1959	77 days
1960	30 days
1961	30 days
1962	25 days
1963	30 days
1964	20 days
1965	30 days
1966	18 days
1967	36 days
1968	60 days
1969	28 days
1970	20 days
1971	25 days
1972	23 days
1973	43 days
1974	42 days
1975	34 days
1976	52 days
1977	44 days
1978	29 days
1979	21 days
1980	63 days
1981	40 days
1982	18 days
1983	33 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

20 years with a frost

Across 20 years with a frost, the median last spring frost at Grass River falls on 21 May and the median first autumn frost on 14 September, which leaves a median of 111 days between them.

Frost dates and growing season at Grass River
Measure	Median, all years	Earliest period	Recent period (1959 to 1983)	Recent against earliest	Fitted trend
Last spring frost	21 May	n/a	21 May	n/a	n/a
First autumn frost	14 September	n/a	14 September	n/a	n/a
Growing days	111 days	n/a	111 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 Grass River standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Grass River 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 2026-10-17 (17 October 2026). Records are computed by this site and are not official.

Data as of 2026-10-17. Last revised 17 October 2026 (2026-10-17).