Grimes Pass 6 S Weather Records (USC00103861)

Record envelope, standing records and threshold days for Grimes Pass 6 S (USC00103861), Idaho, United States, with 41 years of record.

Key Facts for Grimes Pass 6 S

Grimes Pass 6 S (USC00103861) is a weather station in Idaho, United States at 43.97 latitude and -115.85 longitude, 1,458 m (4,783 ft) above sea level.
The station reports from 1909 to 1949, 41 years of record.
64 records set at Grimes Pass 6 S still stand.
Records are tracked for prcp, snow: an element needs 30 years of data to be eligible.
Grimes Pass 6 S set a daily record snowfall of 7.6 cm (3.0 in) on 9 October 1949.

About the Station

Location: Idaho, United States, 43.97 latitude, -115.85 longitude.
Elevation: 1,458 m (4,783 ft).
Period of record: 1909 to 1949, 41 years.
Eligible elements: prcp, snow.

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 Grimes Pass 6 S. 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 Grimes Pass 6 S, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	-5.0 C (23.0 F)	n/a	n/a	n/a
Feb	n/a	n/a	n/a	n/a
Mar	n/a	n/a	n/a	n/a
Apr	-10.0 C (14.0 F)	n/a	n/a	n/a
May	-2.2 C (28.0 F)	n/a	n/a	n/a
Jun	n/a	n/a	n/a	n/a
Jul	n/a	n/a	n/a	n/a
Aug	-2.2 C (28.0 F)	n/a	n/a	n/a
Sep	-1.1 C (30.0 F)	n/a	n/a	n/a
Oct	-3.3 C (26.1 F)	n/a	n/a	n/a
Nov	n/a	-25.6 C (-14.1 F)	n/a	n/a
Dec	-31.1 C (-24.0 F)	n/a	n/a	n/a

Which Years Hold Standing Records

64 standing records

64 records at Grimes Pass 6 S still stand. 1915 holds the most, with 12.

Wettest Day of Each Month

Dec: 90.2 mm (3.6 in)

The wettest day on record for each calendar month at Grimes Pass 6 S. The most was 90.2 mm (3.6 in) on 28 December 1931.

Record daily precipitation for each month at Grimes Pass 6 S
Month	Record daily precipitation (mm)	Date
Jan	51.1 mm (2.0 in)	20 January 1943
Feb	49.8 mm (2.0 in)	9 February 1949
Mar	44.5 mm (1.8 in)	27 March 1940
Apr	24.9 mm (1.0 in)	30 April 1938
May	31.5 mm (1.2 in)	15 May 1911
Jun	33.5 mm (1.3 in)	29 June 1938
Jul	32.8 mm (1.3 in)	13 July 1932
Aug	40.4 mm (1.6 in)	17 August 1941
Sep	29.2 mm (1.1 in)	12 September 1939
Oct	68.3 mm (2.7 in)	29 October 1933
Nov	51.1 mm (2.0 in)	15 November 1930
Dec	90.2 mm (3.6 in)	28 December 1931

Period of Record Coverage

1915 to 1926

11 years of record at Grimes Pass 6 S, 1915 to 1926. 11 years have data for under 90 percent of days and are left out of rankings: 1915, 1916, 1917, 1918, 1919, 1921, 1922, 1923 and others.

Latest Records

Latest records at Grimes Pass 6 S
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
9 October 1949	Grimes Pass 6 S, US	daily snowfall	7.6 cm (3.0 in)	5.1 cm (2.0 in)	38 years	25 of 100 (Routine)
7 October 1949	Grimes Pass 6 S, US	daily snowfall	7.6 cm (3.0 in)	3.0 cm (1.2 in)	26 years	17 of 100 (Routine)
31 May 1949	Grimes Pass 6 S, US	daily rain	19.1 mm (0.8 in)	4.4 mm (0.17 in)	8 years	13 of 100 (Routine)
14 February 1949	Grimes Pass 6 S, US	daily snowfall	43.2 cm (17.0 in)	19.1 cm (7.5 in)	9 years	36 of 100 (Notable)
9 February 1949	Grimes Pass 6 S, US	monthly rain	49.8 mm (2.0 in)	7.9 mm (0.31 in)	3 years	25 of 100 (Routine)
9 February 1949	Grimes Pass 6 S, US	all-time snowfall (Tie)	66.0 cm (26.0 in)	tie	17 years	7 of 100 (Routine)
8 February 1949	Grimes Pass 6 S, US	daily snowfall	15.2 cm (6.0 in)	4.3 cm (1.7 in)	27 years	18 of 100 (Routine)
6 February 1949	Grimes Pass 6 S, US	daily snowfall	40.6 cm (16.0 in)	5.0 cm (2.0 in)	3 years	11 of 100 (Routine)
5 February 1949	Grimes Pass 6 S, US	daily snowfall	40.6 cm (16.0 in)	17.0 cm (6.7 in)	33 years	39 of 100 (Notable)
3 February 1949	Grimes Pass 6 S, US	monthly snowfall (Tie)	45.7 cm (18.0 in)	tie	29 years	5 of 100 (Routine)
31 December 1948	Grimes Pass 6 S, US	daily snowfall	25.4 cm (10.0 in)	5.1 cm (2.0 in)	20 years	17 of 100 (Routine)
11 December 1948	Grimes Pass 6 S, US	daily snowfall	33.0 cm (13.0 in)	16.5 cm (6.5 in)	21 years	32 of 100 (Routine)
11 December 1948	Grimes Pass 6 S, US	daily rain	35.3 mm (1.4 in)	16.5 mm (0.6 in)	11 years	23 of 100 (Routine)
4 December 1948	Grimes Pass 6 S, US	daily snowfall	27.9 cm (11.0 in)	4.8 cm (1.9 in)	39 years	21 of 100 (Routine)
4 December 1948	Grimes Pass 6 S, US	daily rain	20.3 mm (0.8 in)	4.8 mm (0.19 in)	24 years	15 of 100 (Routine)
2 December 1948	Grimes Pass 6 S, US	daily snowfall	10.4 cm (4.1 in)	2.0 cm (0.8 in)	26 years	13 of 100 (Routine)
13 November 1948	Grimes Pass 6 S, US	daily snowfall	22.9 cm (9.0 in)	10.2 cm (4.0 in)	37 years	29 of 100 (Routine)
13 November 1948	Grimes Pass 6 S, US	daily rain	22.9 mm (0.9 in)	4.1 mm (0.16 in)	11 years	11 of 100 (Routine)
2 November 1948	Grimes Pass 6 S, US	daily rain	16.5 mm (0.6 in)	2.5 mm (0.10 in)	29 years	14 of 100 (Routine)
1 November 1948	Grimes Pass 6 S, US	daily rain	22.1 mm (0.9 in)	5.6 mm (0.22 in)	35 years	20 of 100 (Routine)

Extremes by Year

1909 to 1949

Yearly extremes at Grimes Pass 6 S: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	-1.1 C (30.0 F)	1915	-3.3 C (26.1 F)	11
Coldest night (TNn)	-25.6 C (-14.1 F)	1931	-25.6 C (-14.1 F)	1
Wettest day (Rx1day)	90.2 mm (3.6 in)	1931	37.3 mm (1.5 in)	41
Wettest five days (Rx5day)	133.5 mm (5.3 in)	1943	77.6 mm (3.1 in)	41
Longest dry spell (CDD)	82 days	1949	40 days	41

Hottest day (TXx)

The hottest day of the year at Grimes Pass 6 S, 1909 to 1949. The record is -1.1 C (30.0 F) in 1915, marked on the chart; the median year is -3.3 C (26.1 F).

Hottest day (TXx) at Grimes Pass 6 S by year
Year	Hottest day (TXx)
1909	n/a
1910	n/a
1911	n/a
1912	n/a
1913	n/a
1914	n/a
1915	-1.1 C (30.0 F)
1916	-3.3 C (26.1 F)
1917	-5.0 C (23.0 F)
1918	-2.2 C (28.0 F)
1919	-2.2 C (28.0 F)
1920	n/a
1921	-2.2 C (28.0 F)
1922	-3.3 C (26.1 F)
1923	-4.4 C (24.1 F)
1924	-2.2 C (28.0 F)
1925	-3.3 C (26.1 F)
1926	-12.8 C (9.0 F)
1927	n/a
1928	n/a
1929	n/a
1930	n/a
1931	n/a
1932	n/a
1933	n/a
1934	n/a
1935	n/a
1936	n/a
1937	n/a
1938	n/a
1939	n/a
1940	n/a
1941	n/a
1942	n/a
1943	n/a
1944	n/a
1945	n/a
1946	n/a
1947	n/a
1948	n/a
1949	n/a

Coldest night (TNn)

The coldest night of the year at Grimes Pass 6 S, 1909 to 1949. The record is -25.6 C (-14.1 F) in 1931, marked on the chart; the median year is -25.6 C (-14.1 F).

Coldest night (TNn) at Grimes Pass 6 S by year
Year	Coldest night (TNn)
1909	n/a
1910	n/a
1911	n/a
1912	n/a
1913	n/a
1914	n/a
1915	n/a
1916	n/a
1917	n/a
1918	n/a
1919	n/a
1920	n/a
1921	n/a
1922	n/a
1923	n/a
1924	n/a
1925	n/a
1926	n/a
1927	n/a
1928	n/a
1929	n/a
1930	n/a
1931	-25.6 C (-14.1 F)
1932	n/a
1933	n/a
1934	n/a
1935	n/a
1936	n/a
1937	n/a
1938	n/a
1939	n/a
1940	n/a
1941	n/a
1942	n/a
1943	n/a
1944	n/a
1945	n/a
1946	n/a
1947	n/a
1948	n/a
1949	n/a

Wettest day (Rx1day)

The wettest day of the year at Grimes Pass 6 S, 1909 to 1949. The record is 90.2 mm (3.6 in) in 1931, marked on the chart; the median year is 37.3 mm (1.5 in).

Wettest day (Rx1day) at Grimes Pass 6 S by year
Year	Wettest day (Rx1day)
1909	35.6 mm (1.4 in)
1910	38.9 mm (1.5 in)
1911	33.0 mm (1.3 in)
1912	24.6 mm (1.0 in)
1913	43.2 mm (1.7 in)
1914	22.9 mm (0.9 in)
1915	37.6 mm (1.5 in)
1916	41.7 mm (1.6 in)
1917	36.8 mm (1.4 in)
1918	23.6 mm (0.9 in)
1919	35.6 mm (1.4 in)
1920	41.4 mm (1.6 in)
1921	47.0 mm (1.9 in)
1922	25.4 mm (1.0 in)
1923	31.5 mm (1.2 in)
1924	31.2 mm (1.2 in)
1925	36.8 mm (1.4 in)
1926	32.8 mm (1.3 in)
1927	48.3 mm (1.9 in)
1928	41.9 mm (1.6 in)
1929	79.5 mm (3.1 in)
1930	51.1 mm (2.0 in)
1931	90.2 mm (3.6 in)
1932	37.3 mm (1.5 in)
1933	83.8 mm (3.3 in)
1934	37.3 mm (1.5 in)
1935	24.1 mm (0.9 in)
1936	38.1 mm (1.5 in)
1937	68.1 mm (2.7 in)
1938	33.5 mm (1.3 in)
1939	29.2 mm (1.1 in)
1940	44.5 mm (1.8 in)
1941	43.2 mm (1.7 in)
1942	31.2 mm (1.2 in)
1943	51.1 mm (2.0 in)
1944	25.4 mm (1.0 in)
1945	41.9 mm (1.6 in)
1946	35.8 mm (1.4 in)
1947	26.2 mm (1.0 in)
1948	35.3 mm (1.4 in)
1949	49.8 mm (2.0 in)

Wettest five days (Rx5day)

The wettest five days of the year at Grimes Pass 6 S, 1909 to 1949. The record is 133.5 mm (5.3 in) in 1943, marked on the chart; the median year is 77.6 mm (3.1 in).

Wettest five days (Rx5day) at Grimes Pass 6 S by year
Year	Wettest five days (Rx5day)
1909	118.8 mm (4.7 in)
1910	77.2 mm (3.0 in)
1911	67.3 mm (2.6 in)
1912	45.2 mm (1.8 in)
1913	75.3 mm (3.0 in)
1914	64.3 mm (2.5 in)
1915	74.8 mm (2.9 in)
1916	94.0 mm (3.7 in)
1917	97.3 mm (3.8 in)
1918	39.6 mm (1.6 in)
1919	75.0 mm (3.0 in)
1920	78.2 mm (3.1 in)
1921	124.6 mm (4.9 in)
1922	53.3 mm (2.1 in)
1923	46.8 mm (1.8 in)
1924	79.4 mm (3.1 in)
1925	97.6 mm (3.8 in)
1926	85.1 mm (3.4 in)
1927	116.1 mm (4.6 in)
1928	70.9 mm (2.8 in)
1929	93.8 mm (3.7 in)
1930	67.9 mm (2.7 in)
1931	107.2 mm (4.2 in)
1932	108.0 mm (4.3 in)
1933	83.8 mm (3.3 in)
1934	86.3 mm (3.4 in)
1935	48.0 mm (1.9 in)
1936	76.2 mm (3.0 in)
1937	113.6 mm (4.5 in)
1938	76.7 mm (3.0 in)
1939	65.3 mm (2.6 in)
1940	77.6 mm (3.1 in)
1941	65.5 mm (2.6 in)
1942	99.5 mm (3.9 in)
1943	133.5 mm (5.3 in)
1944	58.7 mm (2.3 in)
1945	107.8 mm (4.2 in)
1946	106.6 mm (4.2 in)
1947	47.0 mm (1.9 in)
1948	73.4 mm (2.9 in)
1949	83.8 mm (3.3 in)

Longest dry spell (CDD)

The longest dry spell of the year at Grimes Pass 6 S, 1909 to 1949. The record is 82 days in 1949, marked on the chart; the median year is 40 days.

Longest dry spell (CDD) at Grimes Pass 6 S by year
Year	Longest dry spell (CDD)
1909	20 days
1910	72 days
1911	42 days
1912	27 days
1913	21 days
1914	52 days
1915	15 days
1916	28 days
1917	48 days
1918	24 days
1919	61 days
1920	23 days
1921	51 days
1922	34 days
1923	30 days
1924	30 days
1925	22 days
1926	30 days
1927	46 days
1928	37 days
1929	46 days
1930	66 days
1931	43 days
1932	39 days
1933	34 days
1934	54 days
1935	72 days
1936	56 days
1937	41 days
1938	24 days
1939	29 days
1940	38 days
1941	22 days
1942	62 days
1943	56 days
1944	40 days
1945	43 days
1946	39 days
1947	53 days
1948	50 days
1949	82 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.

Rainfall Return Levels

38 years, 1910 to 1948

A day with at least 36.6 mm (1.4 in) of rain is expected about once in 2 years. A day with at least 103.6 mm (4.1 in) of rain is expected about once in 100 years.

Rainfall return levels at Grimes Pass 6 S: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	36.6 mm (1.4 in)
5 years	49.3 mm (1.9 in)
10 years	59.4 mm (2.3 in)
25 years	74.7 mm (2.9 in)
50 years	88.2 mm (3.5 in)	Longer than the 38 years of record
100 years	103.6 mm (4.1 in)	Longer than the 38 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, 38 years of values from 1910 to 1948.

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: 90.2 mm (3.6 in) in 1931; 83.8 mm (3.3 in) in 1933; 79.5 mm (3.1 in) in 1929.

Download the Data

Data for Grimes Pass 6 S standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Grimes Pass 6 S 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 2025-12-31. Last revised 31 December 2025 (2025-12-31).