Arnprior Grandon Weather Records (CA006100345)

Record envelope, standing records and threshold days for Arnprior Grandon (CA006100345), Ontario, Canada, with 41 years of record.

Key Facts for Arnprior Grandon

Arnprior Grandon (CA006100345) is a weather station in Ontario, Canada at 45.42 latitude and -76.37 longitude, 107 m (351 ft) above sea level.
The station reports from 1959 to 1999, 41 years of record.
1,464 records set at Arnprior Grandon still stand.
Records are tracked for no element yet: an element needs 30 years of data to be eligible.

About the Station

Location: Ontario, Canada, 45.42 latitude, -76.37 longitude.
Elevation: 107 m (351 ft).
Period of record: 1959 to 1999, 41 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 Arnprior Grandon. 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 Arnprior Grandon, 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)	-38.0 C (-36.4 F)	n/a	n/a
Feb	9.0 C (48.2 F)	-37.2 C (-35.0 F)	n/a	n/a
Mar	22.8 C (73.0 F)	-30.5 C (-22.9 F)	n/a	n/a
Apr	30.6 C (87.1 F)	-17.8 C (0.0 F)	n/a	n/a
May	32.2 C (90.0 F)	-7.2 C (19.0 F)	n/a	n/a
Jun	33.3 C (91.9 F)	-1.1 C (30.0 F)	n/a	n/a
Jul	37.2 C (99.0 F)	4.4 C (39.9 F)	n/a	n/a
Aug	37.2 C (99.0 F)	2.0 C (35.6 F)	n/a	n/a
Sep	33.0 C (91.4 F)	-3.3 C (26.1 F)	n/a	n/a
Oct	27.0 C (80.6 F)	-8.3 C (17.1 F)	n/a	n/a
Nov	21.1 C (70.0 F)	-21.1 C (-6.0 F)	n/a	n/a
Dec	15.0 C (59.0 F)	-33.9 C (-29.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Arnprior Grandon still stand. 1979 holds the most, with 91.

Standing records at Arnprior Grandon by the year they were set
Year set	Standing records
1964	61
1965	84
1966	72
1967	88
1968	86
1969	56
1970	78
1971	85
1972	45
1973	80
1974	76
1975	72
1976	86
1977	60
1978	61
1979	91
1980	55
1981	67
1982	79
1983	82

Wettest Day of Each Month

Aug: 58.0 mm (2.3 in)

The wettest day on record for each calendar month at Arnprior Grandon. The most was 58.0 mm (2.3 in) on 4 August 1981.

Record daily precipitation for each month at Arnprior Grandon
Month	Record daily precipitation (mm)	Date
Jan	35.6 mm (1.4 in)	30 January 1966
Feb	33.0 mm (1.3 in)	3 February 1972
Mar	38.4 mm (1.5 in)	31 March 1976
Apr	36.3 mm (1.4 in)	27 April 1973
May	40.4 mm (1.6 in)	19 May 1976
Jun	50.8 mm (2.0 in)	24 June 1967
Jul	45.2 mm (1.8 in)	20 July 1970
Aug	58.0 mm (2.3 in)	4 August 1981
Sep	37.6 mm (1.5 in)	12 September 1963
Oct	47.0 mm (1.9 in)	5 October 1979
Nov	36.1 mm (1.4 in)	7 November 1963
Dec	38.1 mm (1.5 in)	10 December 1969

Period of Record Coverage

1964 to 1983

20 years of record at Arnprior Grandon, 1964 to 1983. 2 years have data for under 90 percent of days and are left out of rankings: 1964, 1972.

Days with data per year at Arnprior Grandon
Year	Days with data	Share of year	Complete
1964	184	50%	No
1965	365	100%	Yes
1966	365	100%	Yes
1967	364	100%	Yes
1968	366	100%	Yes
1969	365	100%	Yes
1970	365	100%	Yes
1971	365	100%	Yes
1972	304	83%	No
1973	359	98%	Yes
1974	361	99%	Yes
1975	365	100%	Yes
1976	365	100%	Yes
1977	349	96%	Yes
1978	365	100%	Yes
1979	365	100%	Yes
1980	365	100%	Yes
1981	355	97%	Yes
1982	357	98%	Yes
1983	362	99%	Yes

Latest Records

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

Climate Trend

16 complete years, 1965 to 1983

One stripe for each of 16 complete years at Arnprior Grandon, 1965 to 1983. Blue stripes are years cooler than the station's own mean of 5.2 C (41.4 F); red stripes are warmer. The coolest year was 1976, at 4.6 C (40.3 F), and the warmest was 1975, at 6.1 C (43.0 F). The strongest colour marks a difference of 0.9 C (1.6 F).

Annual mean temperature at Arnprior Grandon as warming stripes, 1965 to 1983
Year	Annual mean temperature	Difference from the station mean
1965	4.9 C	-0.30 C
1966	5.4 C	+0.19 C
1967	4.9 C	-0.37 C
1968	5.1 C	-0.10 C
1969	5.5 C	+0.29 C
1970	4.8 C	-0.46 C
1971	5.0 C	-0.21 C
1973	6.0 C	+0.79 C
1974	5.0 C	-0.20 C
1975	6.1 C	+0.87 C
1976	4.6 C	-0.63 C
1978	4.8 C	-0.45 C
1979	5.7 C	+0.50 C
1980	4.8 C	-0.40 C
1982	5.2 C	-0.06 C
1983	5.8 C	+0.58 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

1959 to 1983

Yearly extremes at Arnprior Grandon: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	37.2 C (99.0 F)	1975	33.3 C (91.9 F)	20
Coldest night (TNn)	-38.0 C (-36.4 F)	1981	-33.4 C (-28.2 F)	20
Wettest day (Rx1day)	58.0 mm (2.3 in)	1981	36.1 mm (1.4 in)	25
Wettest five days (Rx5day)	98.8 mm (3.9 in)	1967	54.6 mm (2.1 in)	25
Longest dry spell (CDD)	35 days	1978	16 days	25

Hottest day (TXx)

The hottest day of the year at Arnprior Grandon, 1959 to 1983. The record is 37.2 C (99.0 F) in 1975, marked on the chart; the median year is 33.3 C (91.9 F).

Hottest day (TXx) at Arnprior Grandon by year
Year	Hottest day (TXx)
1959	n/a
1960	n/a
1961	n/a
1962	n/a
1963	n/a
1964	35.0 C (95.0 F)
1965	33.3 C (91.9 F)
1966	34.4 C (93.9 F)
1967	30.6 C (87.1 F)
1968	33.3 C (91.9 F)
1969	34.4 C (93.9 F)
1970	32.8 C (91.0 F)
1971	33.3 C (91.9 F)
1972	32.2 C (90.0 F)
1973	33.3 C (91.9 F)
1974	32.2 C (90.0 F)
1975	37.2 C (99.0 F)
1976	32.2 C (90.0 F)
1977	37.2 C (99.0 F)
1978	33.0 C (91.4 F)
1979	33.0 C (91.4 F)
1980	31.5 C (88.7 F)
1981	33.0 C (91.4 F)
1982	34.5 C (94.1 F)
1983	34.0 C (93.2 F)

Coldest night (TNn)

The coldest night of the year at Arnprior Grandon, 1959 to 1983. The record is -38.0 C (-36.4 F) in 1981, marked on the chart; the median year is -33.4 C (-28.2 F).

Coldest night (TNn) at Arnprior Grandon by year
Year	Coldest night (TNn)
1959	n/a
1960	n/a
1961	n/a
1962	n/a
1963	n/a
1964	-23.3 C (-9.9 F)
1965	-29.4 C (-20.9 F)
1966	-32.8 C (-27.0 F)
1967	-35.6 C (-32.1 F)
1968	-33.9 C (-29.0 F)
1969	-27.8 C (-18.0 F)
1970	-36.1 C (-33.0 F)
1971	-37.2 C (-35.0 F)
1972	-35.0 C (-31.0 F)
1973	-34.4 C (-29.9 F)
1974	-32.2 C (-26.0 F)
1975	-30.6 C (-23.1 F)
1976	-36.7 C (-34.1 F)
1977	-34.4 C (-29.9 F)
1978	-29.4 C (-20.9 F)
1979	-34.0 C (-29.2 F)
1980	-32.0 C (-25.6 F)
1981	-38.0 C (-36.4 F)
1982	-33.0 C (-27.4 F)
1983	-31.0 C (-23.8 F)

Wettest day (Rx1day)

The wettest day of the year at Arnprior Grandon, 1959 to 1983. The record is 58.0 mm (2.3 in) in 1981, marked on the chart; the median year is 36.1 mm (1.4 in).

Wettest day (Rx1day) at Arnprior Grandon by year
Year	Wettest day (Rx1day)
1959	41.9 mm (1.6 in)
1960	30.5 mm (1.2 in)
1961	20.8 mm (0.8 in)
1962	34.8 mm (1.4 in)
1963	38.1 mm (1.5 in)
1964	35.1 mm (1.4 in)
1965	23.9 mm (0.9 in)
1966	35.6 mm (1.4 in)
1967	50.8 mm (2.0 in)
1968	36.1 mm (1.4 in)
1969	43.2 mm (1.7 in)
1970	45.2 mm (1.8 in)
1971	43.2 mm (1.7 in)
1972	37.1 mm (1.5 in)
1973	54.1 mm (2.1 in)
1974	31.5 mm (1.2 in)
1975	24.9 mm (1.0 in)
1976	40.4 mm (1.6 in)
1977	32.3 mm (1.3 in)
1978	34.2 mm (1.3 in)
1979	47.0 mm (1.9 in)
1980	43.0 mm (1.7 in)
1981	58.0 mm (2.3 in)
1982	36.0 mm (1.4 in)
1983	26.2 mm (1.0 in)

Wettest five days (Rx5day)

The wettest five days of the year at Arnprior Grandon, 1959 to 1983. The record is 98.8 mm (3.9 in) in 1967, marked on the chart; the median year is 54.6 mm (2.1 in).

Wettest five days (Rx5day) at Arnprior Grandon by year
Year	Wettest five days (Rx5day)
1959	47.0 mm (1.9 in)
1960	38.1 mm (1.5 in)
1961	45.3 mm (1.8 in)
1962	54.6 mm (2.1 in)
1963	73.1 mm (2.9 in)
1964	54.4 mm (2.1 in)
1965	34.3 mm (1.4 in)
1966	54.2 mm (2.1 in)
1967	98.8 mm (3.9 in)
1968	60.5 mm (2.4 in)
1969	62.7 mm (2.5 in)
1970	58.7 mm (2.3 in)
1971	52.9 mm (2.1 in)
1972	54.6 mm (2.1 in)
1973	59.7 mm (2.4 in)
1974	51.1 mm (2.0 in)
1975	46.5 mm (1.8 in)
1976	66.8 mm (2.6 in)
1977	60.9 mm (2.4 in)
1978	37.5 mm (1.5 in)
1979	67.1 mm (2.6 in)
1980	52.0 mm (2.0 in)
1981	73.6 mm (2.9 in)
1982	58.0 mm (2.3 in)
1983	62.2 mm (2.4 in)

Longest dry spell (CDD)

The longest dry spell of the year at Arnprior Grandon, 1959 to 1983. The record is 35 days in 1978, marked on the chart; the median year is 16 days.

Longest dry spell (CDD) at Arnprior Grandon by year
Year	Longest dry spell (CDD)
1959	11 days
1960	22 days
1961	29 days
1962	17 days
1963	19 days
1964	15 days
1965	20 days
1966	14 days
1967	21 days
1968	14 days
1969	15 days
1970	21 days
1971	15 days
1972	21 days
1973	16 days
1974	14 days
1975	16 days
1976	13 days
1977	14 days
1978	35 days
1979	19 days
1980	27 days
1981	16 days
1982	14 days
1983	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.

Download the Data

Data for Arnprior Grandon standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Arnprior Grandon 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 2026-10-13 (13 October 2026). Records are computed by this site and are not official.

Data as of 2026-10-13. Last revised 13 October 2026 (2026-10-13).