Helena 6 N Weather Records (USC00244050)

Record envelope, standing records and threshold days for Helena 6 N (USC00244050), Montana, United States, with 57 years of record.

Key Facts for Helena 6 N

Helena 6 N (USC00244050) is a weather station in Montana, United States at 46.67 latitude and -112.05 longitude, 1,159 m (3,802 ft) above sea level.
The station reports from 1923 to 1979, 57 years of record.
2 records set at Helena 6 N still stand.
Records are tracked for prcp, snow: an element needs 30 years of data to be eligible.
Helena 6 N set a daily record precipitation of 26.2 mm (1.0 in) on 18 June 1979.

About the Station

Location: Montana, United States, 46.67 latitude, -112.05 longitude.
Elevation: 1,159 m (3,802 ft).
Period of record: 1923 to 1979, 57 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 Helena 6 N. 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 Helena 6 N, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	n/a	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	n/a	n/a	n/a	n/a
May	n/a	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	n/a	n/a	n/a	n/a
Sep	n/a	-5.6 C (21.9 F)	n/a	n/a
Oct	n/a	n/a	n/a	n/a
Nov	n/a	n/a	n/a	n/a
Dec	n/a	n/a	n/a	n/a

Which Years Hold Standing Records

2 standing records

2 records at Helena 6 N still stand. 1949 holds the most, with 2.

Wettest Day of Each Month

Apr: 68.8 mm (2.7 in)

The wettest day on record for each calendar month at Helena 6 N. The most was 68.8 mm (2.7 in) on 30 April 1951.

Record daily precipitation for each month at Helena 6 N
Month	Record daily precipitation (mm)	Date
Jan	11.9 mm (0.5 in)	21 January 1969
Feb	10.2 mm (0.4 in)	11 February 1936
Mar	14.5 mm (0.6 in)	26 March 1952
Apr	68.8 mm (2.7 in)	30 April 1951
May	43.4 mm (1.7 in)	29 May 1927
Jun	49.8 mm (2.0 in)	9 June 1947
Jul	25.9 mm (1.0 in)	7 July 1969
Aug	56.9 mm (2.2 in)	21 August 1933
Sep	30.5 mm (1.2 in)	16 September 1947
Oct	25.9 mm (1.0 in)	4 October 1946
Nov	10.9 mm (0.4 in)	2 November 1948
Dec	14.7 mm (0.6 in)	10 December 1929

Latest Records

Latest records at Helena 6 N
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
18 June 1979	Helena 6 N, US	daily rain	26.2 mm (1.0 in)	7.4 mm (0.29 in)	50 years	32 of 100 (Routine)
23 April 1979	Helena 6 N, US	daily snowfall	5.1 cm (2.0 in)	5.1 cm (2.0 in)	52 years	30 of 100 (Routine)
18 April 1979	Helena 6 N, US	daily rain	10.7 mm (0.4 in)	3.1 mm (0.12 in)	32 years	19 of 100 (Routine)
10 April 1979	Helena 6 N, US	daily rain	2.5 mm (0.10 in)	1.0 mm (0.04 in)	54 years	20 of 100 (Routine)
28 March 1979	Helena 6 N, US	daily snowfall	7.6 cm (3.0 in)	2.5 cm (1.0 in)	24 years	19 of 100 (Routine)
27 March 1979	Helena 6 N, US	daily snowfall (Tie)	10.2 cm (4.0 in)	tie	50 years	5 of 100 (Routine)
26 March 1979	Helena 6 N, US	daily snowfall (Tie)	2.5 cm (1.0 in)	tie	28 years	3 of 100 (Routine)
17 March 1979	Helena 6 N, US	daily rain	5.3 mm (0.21 in)	0.2 mm (0.01 in)	10 years	8 of 100 (Routine)
14 February 1979	Helena 6 N, US	daily snowfall	10.2 cm (4.0 in)	6.4 cm (2.5 in)	40 years	33 of 100 (Routine)
14 February 1979	Helena 6 N, US	daily rain	6.1 mm (0.24 in)	2.3 mm (0.09 in)	20 years	20 of 100 (Routine)
12 January 1979	Helena 6 N, US	daily rain (Tie)	2.5 mm (0.10 in)	tie	9 years	1 of 100 (Routine)
11 January 1979	Helena 6 N, US	daily snowfall	2.5 cm (1.0 in)	0.5 cm (0.2 in)	52 years	20 of 100 (Routine)
4 December 1978	Helena 6 N, US	daily rain	5.1 mm (0.20 in)	1.3 mm (0.05 in)	28 years	18 of 100 (Routine)
1 December 1978	Helena 6 N, US	daily snowfall	7.6 cm (3.0 in)	2.5 cm (1.0 in)	28 years	18 of 100 (Routine)
19 November 1978	Helena 6 N, US	daily snowfall	12.7 cm (5.0 in)	3.8 cm (1.5 in)	4 years	15 of 100 (Routine)
19 November 1978	Helena 6 N, US	daily rain (Tie)	6.4 mm (0.25 in)	tie	4 years	1 of 100 (Routine)
18 November 1978	Helena 6 N, US	monthly snowfall	20.3 cm (8.0 in)	5.1 cm (2.0 in)	31 years	37 of 100 (Notable)
18 November 1978	Helena 6 N, US	daily rain	8.4 mm (0.33 in)	1.5 mm (0.06 in)	28 years	20 of 100 (Routine)
17 November 1978	Helena 6 N, US	daily snowfall	5.1 cm (2.0 in)	2.6 cm (1.0 in)	31 years	20 of 100 (Routine)
13 November 1978	Helena 6 N, US	daily rain	3.6 mm (0.14 in)	0.6 mm (0.02 in)	33 years	18 of 100 (Routine)

Extremes by Year

1923 to 1979

Yearly extremes at Helena 6 N: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Coldest night (TNn)	-5.6 C (21.9 F)	1949	-5.6 C (21.9 F)	1
Wettest day (Rx1day)	68.8 mm (2.7 in)	1951	23.9 mm (0.9 in)	57
Wettest five days (Rx5day)	76.5 mm (3.0 in)	1947	37.3 mm (1.5 in)	57
Longest dry spell (CDD)	95 days	1973	41 days	57

Coldest night (TNn)

The coldest night of the year at Helena 6 N, 1923 to 1979. The record is -5.6 C (21.9 F) in 1949, marked on the chart; the median year is -5.6 C (21.9 F).

Coldest night (TNn) at Helena 6 N by year
Year	Coldest night (TNn)
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	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	-5.6 C (21.9 F)
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	n/a
1965	n/a
1966	n/a
1967	n/a
1968	n/a
1969	n/a
1970	n/a
1971	n/a
1972	n/a
1973	n/a
1974	n/a
1975	n/a
1976	n/a
1977	n/a
1978	n/a
1979	n/a

Wettest day (Rx1day)

The wettest day of the year at Helena 6 N, 1923 to 1979. The record is 68.8 mm (2.7 in) in 1951, marked on the chart; the median year is 23.9 mm (0.9 in).

Wettest day (Rx1day) at Helena 6 N by year
Year	Wettest day (Rx1day)
1923	20.3 mm (0.8 in)
1924	10.2 mm (0.4 in)
1925	43.4 mm (1.7 in)
1926	21.3 mm (0.8 in)
1927	43.4 mm (1.7 in)
1928	19.1 mm (0.8 in)
1929	14.7 mm (0.6 in)
1930	14.5 mm (0.6 in)
1931	15.5 mm (0.6 in)
1932	14.5 mm (0.6 in)
1933	56.9 mm (2.2 in)
1934	16.0 mm (0.6 in)
1935	11.7 mm (0.5 in)
1936	17.0 mm (0.7 in)
1937	29.5 mm (1.2 in)
1938	18.5 mm (0.7 in)
1939	15.2 mm (0.6 in)
1940	26.7 mm (1.1 in)
1941	31.5 mm (1.2 in)
1942	18.0 mm (0.7 in)
1943	18.3 mm (0.7 in)
1944	24.1 mm (0.9 in)
1945	24.4 mm (1.0 in)
1946	25.9 mm (1.0 in)
1947	49.8 mm (2.0 in)
1948	31.2 mm (1.2 in)
1949	16.3 mm (0.6 in)
1950	17.3 mm (0.7 in)
1951	68.8 mm (2.7 in)
1952	20.3 mm (0.8 in)
1953	31.5 mm (1.2 in)
1954	30.0 mm (1.2 in)
1955	19.6 mm (0.8 in)
1956	24.9 mm (1.0 in)
1957	40.9 mm (1.6 in)
1958	27.2 mm (1.1 in)
1959	14.0 mm (0.6 in)
1960	19.1 mm (0.8 in)
1961	9.9 mm (0.39 in)
1962	24.9 mm (1.0 in)
1963	19.3 mm (0.8 in)
1964	31.2 mm (1.2 in)
1965	25.7 mm (1.0 in)
1966	7.9 mm (0.31 in)
1967	23.1 mm (0.9 in)
1968	25.9 mm (1.0 in)
1969	31.8 mm (1.3 in)
1970	27.9 mm (1.1 in)
1971	23.9 mm (0.9 in)
1972	12.7 mm (0.5 in)
1973	11.9 mm (0.5 in)
1974	39.6 mm (1.6 in)
1975	39.9 mm (1.6 in)
1976	24.1 mm (0.9 in)
1977	26.9 mm (1.1 in)
1978	20.8 mm (0.8 in)
1979	26.2 mm (1.0 in)

Wettest five days (Rx5day)

The wettest five days of the year at Helena 6 N, 1923 to 1979. The record is 76.5 mm (3.0 in) in 1947, marked on the chart; the median year is 37.3 mm (1.5 in).

Wettest five days (Rx5day) at Helena 6 N by year
Year	Wettest five days (Rx5day)
1923	26.4 mm (1.0 in)
1924	12.5 mm (0.5 in)
1925	49.0 mm (1.9 in)
1926	41.2 mm (1.6 in)
1927	72.6 mm (2.9 in)
1928	31.0 mm (1.2 in)
1929	34.5 mm (1.4 in)
1930	23.6 mm (0.9 in)
1931	22.6 mm (0.9 in)
1932	24.3 mm (1.0 in)
1933	71.6 mm (2.8 in)
1934	40.1 mm (1.6 in)
1935	17.1 mm (0.7 in)
1936	22.7 mm (0.9 in)
1937	44.6 mm (1.8 in)
1938	38.9 mm (1.5 in)
1939	28.0 mm (1.1 in)
1940	37.3 mm (1.5 in)
1941	53.7 mm (2.1 in)
1942	25.4 mm (1.0 in)
1943	43.2 mm (1.7 in)
1944	51.7 mm (2.0 in)
1945	41.2 mm (1.6 in)
1946	46.7 mm (1.8 in)
1947	76.5 mm (3.0 in)
1948	62.4 mm (2.5 in)
1949	26.8 mm (1.1 in)
1950	28.7 mm (1.1 in)
1951	71.1 mm (2.8 in)
1952	27.5 mm (1.1 in)
1953	62.2 mm (2.4 in)
1954	56.2 mm (2.2 in)
1955	28.3 mm (1.1 in)
1956	26.9 mm (1.1 in)
1957	63.3 mm (2.5 in)
1958	51.6 mm (2.0 in)
1959	30.2 mm (1.2 in)
1960	25.2 mm (1.0 in)
1961	16.5 mm (0.6 in)
1962	40.4 mm (1.6 in)
1963	27.5 mm (1.1 in)
1964	57.4 mm (2.3 in)
1965	49.2 mm (1.9 in)
1966	12.5 mm (0.5 in)
1967	38.6 mm (1.5 in)
1968	36.4 mm (1.4 in)
1969	66.6 mm (2.6 in)
1970	32.8 mm (1.3 in)
1971	33.5 mm (1.3 in)
1972	22.4 mm (0.9 in)
1973	14.2 mm (0.6 in)
1974	39.6 mm (1.6 in)
1975	65.4 mm (2.6 in)
1976	36.6 mm (1.4 in)
1977	36.3 mm (1.4 in)
1978	54.9 mm (2.2 in)
1979	46.5 mm (1.8 in)

Longest dry spell (CDD)

The longest dry spell of the year at Helena 6 N, 1923 to 1979. The record is 95 days in 1973, marked on the chart; the median year is 41 days.

Longest dry spell (CDD) at Helena 6 N by year
Year	Longest dry spell (CDD)
1923	46 days
1924	62 days
1925	45 days
1926	39 days
1927	21 days
1928	45 days
1929	38 days
1930	47 days
1931	53 days
1932	41 days
1933	59 days
1934	54 days
1935	77 days
1936	29 days
1937	41 days
1938	41 days
1939	67 days
1940	37 days
1941	43 days
1942	34 days
1943	37 days
1944	38 days
1945	26 days
1946	57 days
1947	26 days
1948	34 days
1949	26 days
1950	34 days
1951	30 days
1952	30 days
1953	82 days
1954	34 days
1955	57 days
1956	50 days
1957	34 days
1958	27 days
1959	56 days
1960	48 days
1961	30 days
1962	34 days
1963	58 days
1964	59 days
1965	42 days
1966	46 days
1967	30 days
1968	72 days
1969	53 days
1970	42 days
1971	39 days
1972	28 days
1973	95 days
1974	28 days
1975	24 days
1976	60 days
1977	40 days
1978	61 days
1979	23 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

55 years, 1924 to 1978

A day with at least 22.2 mm (0.9 in) of rain is expected about once in 2 years. A day with at least 67.8 mm (2.7 in) of rain is expected about once in 100 years.

Rainfall return levels at Helena 6 N: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	22.2 mm (0.9 in)
5 years	32.4 mm (1.3 in)
10 years	39.9 mm (1.6 in)
25 years	50.3 mm (2.0 in)
50 years	58.8 mm (2.3 in)
100 years	67.8 mm (2.7 in)	Longer than the 55 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, 55 years of values from 1924 to 1978.

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: 68.8 mm (2.7 in) in 1951; 56.9 mm (2.2 in) in 1933; 49.8 mm (2.0 in) in 1947.

Download the Data

Data for Helena 6 N standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Helena 6 N 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).