Record envelope, standing records and threshold days for Lonesome Lake (USC00245177), Montana, United States, with 34 years of record.
Key Facts for Lonesome Lake
Lonesome Lake (USC00245177) is a weather station in Montana, United States at 48.25 latitude and -110.20 longitude, 842 m (2,762 ft) above sea level.
The station reports from 1948 to 1981, 34 years of record.
1,464 records set at Lonesome Lake still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Lonesome Lake set a daily record high maximum temperature of 13.9 C (57.0 F) on 23 January 1981.
About the Station
Location: Montana, United States, 48.25 latitude, -110.20 longitude.
Elevation: 842 m (2,762 ft).
Period of record: 1948 to 1981, 34 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.
Daily Record Envelope and 2026
0 days at or beyond a record
Record highRecord low2026 daily maximum2026 daily minimum
The band shows the record high and record low for each calendar day at Lonesome Lake. 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 Lonesome Lake, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
18.9 C (66.0 F)
-46.7 C (-52.1 F)
n/a
n/a
Feb
19.4 C (66.9 F)
-37.2 C (-35.0 F)
n/a
n/a
Mar
24.4 C (75.9 F)
-41.7 C (-43.1 F)
n/a
n/a
Apr
32.8 C (91.0 F)
-25.0 C (-13.0 F)
n/a
n/a
May
35.0 C (95.0 F)
-13.3 C (8.1 F)
n/a
n/a
Jun
36.7 C (98.1 F)
-2.8 C (27.0 F)
n/a
n/a
Jul
40.6 C (105.1 F)
1.1 C (34.0 F)
n/a
n/a
Aug
43.3 C (109.9 F)
-3.9 C (25.0 F)
n/a
n/a
Sep
38.3 C (100.9 F)
-8.3 C (17.1 F)
n/a
n/a
Oct
32.2 C (90.0 F)
-22.2 C (-8.0 F)
n/a
n/a
Nov
24.4 C (75.9 F)
-38.9 C (-38.0 F)
n/a
n/a
Dec
18.3 C (64.9 F)
-41.7 C (-43.1 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at Lonesome Lake still stand. 1951 holds the most, with 72.
Standing records at Lonesome Lake by the year they were set
Year set
Standing records
1948
23
1949
63
1950
68
1951
72
1952
22
1953
35
1954
50
1955
45
1956
43
1957
47
1958
35
1959
49
1960
42
1961
60
1962
61
1963
53
1964
34
1965
47
1966
45
1967
49
1968
52
1969
55
1970
39
1971
42
1972
51
1973
40
1974
37
1975
43
1976
32
1977
45
1978
23
1979
24
1980
33
1981
5
Wettest Day of Each Month
May: 90.2 mm (3.6 in)
The wettest day on record for each calendar month at Lonesome Lake. The most was 90.2 mm (3.6 in) on 31 May 1961.
Record daily precipitation for each month at Lonesome Lake
Month
Record daily precipitation (mm)
Date
Jan
20.8 mm (0.8 in)
26 January 1952
Feb
11.4 mm (0.4 in)
24 February 1977
Mar
11.9 mm (0.5 in)
5 March 1951
Apr
37.6 mm (1.5 in)
20 April 1973
May
90.2 mm (3.6 in)
31 May 1961
Jun
44.2 mm (1.7 in)
19 June 1975
Jul
41.7 mm (1.6 in)
19 July 1948
Aug
74.9 mm (2.9 in)
15 August 1968
Sep
29.7 mm (1.2 in)
12 September 1978
Oct
26.2 mm (1.0 in)
20 October 1958
Nov
13.5 mm (0.5 in)
4 November 1958
Dec
14.5 mm (0.6 in)
16 December 1977
Period of Record Coverage
1948 to 1981
Complete yearUnder 90 percent of days
34 years of record at Lonesome Lake, 1948 to 1981. 10 years have data for under 90 percent of days and are left out of rankings: 1948, 1950, 1952, 1955, 1963, 1964, 1973, 1978 and others.
Cooler than the station meanWarmer than the station mean
One stripe for each of 20 complete years at Lonesome Lake, 1949 to 1977. Blue stripes are years cooler than the station's own mean of 5.5 C (41.9 F); red stripes are warmer. The coolest year was 1951, at 2.7 C (36.9 F), and the warmest was 1953, at 7.2 C (44.9 F). The strongest colour marks a difference of 2.8 C (5.0 F).
Annual mean temperature at Lonesome Lake as warming stripes, 1949 to 1977
Year
Annual mean temperature
Difference from the station mean
1949
4.8 C
-0.64 C
1951
2.7 C
-2.74 C
1953
7.2 C
+1.69 C
1954
5.7 C
+0.19 C
1956
5.2 C
-0.27 C
1957
5.5 C
-0.03 C
1958
5.9 C
+0.45 C
1959
5.2 C
-0.31 C
1960
5.7 C
+0.24 C
1961
7.1 C
+1.61 C
1962
6.8 C
+1.31 C
1965
4.0 C
-1.45 C
1967
6.3 C
+0.77 C
1969
4.4 C
-1.08 C
1970
4.7 C
-0.82 C
1971
5.5 C
+0.03 C
1972
4.9 C
-0.63 C
1974
7.2 C
+1.68 C
1975
4.9 C
-0.54 C
1977
6.1 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
1948 to 1981
Yearly extremes at Lonesome Lake: 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)
1961
37.8 C (100.0 F)
34
Coldest night (TNn)
-46.7 C (-52.1 F)
1969
-38.3 C (-36.9 F)
34
Wettest day (Rx1day)
90.2 mm (3.6 in)
1961
31.0 mm (1.2 in)
34
Wettest five days (Rx5day)
101.6 mm (4.0 in)
1961
43.5 mm (1.7 in)
34
Longest dry spell (CDD)
64 days
1952
38 days
34
Hottest day (TXx)
The hottest day of the year at Lonesome Lake, 1948 to 1981. The record is 43.3 C (109.9 F) in 1961, marked on the chart; the median year is 37.8 C (100.0 F).
Hottest day (TXx) at Lonesome Lake by year
Year
Hottest day (TXx)
1948
36.7 C (98.1 F)
1949
41.1 C (106.0 F)
1950
36.7 C (98.1 F)
1951
40.0 C (104.0 F)
1952
36.7 C (98.1 F)
1953
40.0 C (104.0 F)
1954
36.7 C (98.1 F)
1955
36.1 C (97.0 F)
1956
37.8 C (100.0 F)
1957
37.8 C (100.0 F)
1958
36.7 C (98.1 F)
1959
37.8 C (100.0 F)
1960
40.6 C (105.1 F)
1961
43.3 C (109.9 F)
1962
36.1 C (97.0 F)
1963
40.0 C (104.0 F)
1964
39.4 C (102.9 F)
1965
37.2 C (99.0 F)
1966
41.1 C (106.0 F)
1967
38.3 C (100.9 F)
1968
37.8 C (100.0 F)
1969
42.8 C (109.0 F)
1970
40.0 C (104.0 F)
1971
40.0 C (104.0 F)
1972
37.2 C (99.0 F)
1973
39.4 C (102.9 F)
1974
37.8 C (100.0 F)
1975
39.4 C (102.9 F)
1976
38.3 C (100.9 F)
1977
36.1 C (97.0 F)
1978
35.0 C (95.0 F)
1979
36.1 C (97.0 F)
1980
36.7 C (98.1 F)
1981
15.0 C (59.0 F)
Coldest night (TNn)
The coldest night of the year at Lonesome Lake, 1948 to 1981. The record is -46.7 C (-52.1 F) in 1969, marked on the chart; the median year is -38.3 C (-36.9 F).
Coldest night (TNn) at Lonesome Lake by year
Year
Coldest night (TNn)
1948
-34.4 C (-29.9 F)
1949
-41.1 C (-42.0 F)
1950
-42.2 C (-44.0 F)
1951
-41.7 C (-43.1 F)
1952
-33.3 C (-27.9 F)
1953
-26.7 C (-16.1 F)
1954
-46.1 C (-51.0 F)
1955
-38.9 C (-38.0 F)
1956
-38.3 C (-36.9 F)
1957
-46.1 C (-51.0 F)
1958
-41.1 C (-42.0 F)
1959
-35.6 C (-32.1 F)
1960
-36.1 C (-33.0 F)
1961
-38.9 C (-38.0 F)
1962
-34.4 C (-29.9 F)
1963
-38.3 C (-36.9 F)
1964
-41.1 C (-42.0 F)
1965
-33.9 C (-29.0 F)
1966
-36.7 C (-34.1 F)
1967
-36.1 C (-33.0 F)
1968
-40.6 C (-41.1 F)
1969
-46.7 C (-52.1 F)
1970
-37.2 C (-35.0 F)
1971
-38.9 C (-38.0 F)
1972
-41.7 C (-43.1 F)
1973
-30.6 C (-23.1 F)
1974
-40.0 C (-40.0 F)
1975
-37.2 C (-35.0 F)
1976
-33.9 C (-29.0 F)
1977
-38.9 C (-38.0 F)
1978
-37.2 C (-35.0 F)
1979
-41.1 C (-42.0 F)
1980
-35.0 C (-31.0 F)
1981
-16.1 C (3.0 F)
Wettest day (Rx1day)
The wettest day of the year at Lonesome Lake, 1948 to 1981. The record is 90.2 mm (3.6 in) in 1961, marked on the chart; the median year is 31.0 mm (1.2 in).
Wettest day (Rx1day) at Lonesome Lake by year
Year
Wettest day (Rx1day)
1948
41.7 mm (1.6 in)
1949
21.6 mm (0.9 in)
1950
39.4 mm (1.6 in)
1951
30.5 mm (1.2 in)
1952
23.1 mm (0.9 in)
1953
33.8 mm (1.3 in)
1954
43.2 mm (1.7 in)
1955
31.8 mm (1.3 in)
1956
29.2 mm (1.1 in)
1957
21.6 mm (0.9 in)
1958
33.0 mm (1.3 in)
1959
36.1 mm (1.4 in)
1960
11.9 mm (0.5 in)
1961
90.2 mm (3.6 in)
1962
29.2 mm (1.1 in)
1963
20.1 mm (0.8 in)
1964
22.4 mm (0.9 in)
1965
22.9 mm (0.9 in)
1966
23.6 mm (0.9 in)
1967
24.9 mm (1.0 in)
1968
74.9 mm (2.9 in)
1969
16.3 mm (0.6 in)
1970
36.3 mm (1.4 in)
1971
27.7 mm (1.1 in)
1972
19.3 mm (0.8 in)
1973
37.6 mm (1.5 in)
1974
78.7 mm (3.1 in)
1975
44.2 mm (1.7 in)
1976
18.0 mm (0.7 in)
1977
32.5 mm (1.3 in)
1978
33.5 mm (1.3 in)
1979
31.5 mm (1.2 in)
1980
33.0 mm (1.3 in)
1981
2.0 mm (0.08 in)
Wettest five days (Rx5day)
The wettest five days of the year at Lonesome Lake, 1948 to 1981. The record is 101.6 mm (4.0 in) in 1961, marked on the chart; the median year is 43.5 mm (1.7 in).
Wettest five days (Rx5day) at Lonesome Lake by year
Year
Wettest five days (Rx5day)
1948
50.1 mm (2.0 in)
1949
21.6 mm (0.9 in)
1950
45.3 mm (1.8 in)
1951
43.9 mm (1.7 in)
1952
26.6 mm (1.0 in)
1953
53.1 mm (2.1 in)
1954
43.5 mm (1.7 in)
1955
41.0 mm (1.6 in)
1956
32.0 mm (1.3 in)
1957
43.5 mm (1.7 in)
1958
49.0 mm (1.9 in)
1959
54.9 mm (2.2 in)
1960
29.3 mm (1.2 in)
1961
101.6 mm (4.0 in)
1962
42.2 mm (1.7 in)
1963
33.4 mm (1.3 in)
1964
30.8 mm (1.2 in)
1965
41.9 mm (1.6 in)
1966
26.4 mm (1.0 in)
1967
38.6 mm (1.5 in)
1968
90.9 mm (3.6 in)
1969
54.6 mm (2.1 in)
1970
65.3 mm (2.6 in)
1971
42.0 mm (1.7 in)
1972
24.9 mm (1.0 in)
1973
55.9 mm (2.2 in)
1974
100.3 mm (3.9 in)
1975
69.6 mm (2.7 in)
1976
45.2 mm (1.8 in)
1977
45.7 mm (1.8 in)
1978
42.9 mm (1.7 in)
1979
33.5 mm (1.3 in)
1980
57.3 mm (2.3 in)
1981
3.8 mm (0.15 in)
Longest dry spell (CDD)
The longest dry spell of the year at Lonesome Lake, 1948 to 1981. The record is 64 days in 1952, marked on the chart; the median year is 38 days.
Longest dry spell (CDD) at Lonesome Lake by year
Year
Longest dry spell (CDD)
1948
30 days
1949
56 days
1950
48 days
1951
52 days
1952
64 days
1953
47 days
1954
35 days
1955
35 days
1956
36 days
1957
45 days
1958
37 days
1959
43 days
1960
42 days
1961
33 days
1962
34 days
1963
29 days
1964
24 days
1965
49 days
1966
38 days
1967
30 days
1968
33 days
1969
59 days
1970
31 days
1971
39 days
1972
22 days
1973
43 days
1974
50 days
1975
31 days
1976
49 days
1977
42 days
1978
27 days
1979
33 days
1980
42 days
1981
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.
Frost Dates and Growing Season
20 years with a frost
Across 20 years with a frost, the median last spring frost at Lonesome Lake falls on 29 May and the median first autumn frost on 11 September, which leaves a median of 104 days between them.
Frost dates and growing season at Lonesome Lake
Measure
Median, all years
Earliest period
Recent period (1949 to 1977)
Recent against earliest
Fitted trend
Last spring frost
29 May
n/a
29 May
n/a
n/a
First autumn frost
11 September
n/a
11 September
n/a
n/a
Growing days
104 days
n/a
104 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.
Rainfall Return Levels
30 years, 1949 to 1980
A day with at least 28.1 mm (1.1 in) of rain is expected about once in 2 years. A day with at least 110.2 mm (4.3 in) of rain is expected about once in 100 years.
Rainfall return levels at Lonesome Lake: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
28.1 mm (1.1 in)
5 years
41.4 mm (1.6 in)
10 years
52.9 mm (2.1 in)
25 years
71.5 mm (2.8 in)
50 years
89.0 mm (3.5 in)
Longer than the 30 years of record
100 years
110.2 mm (4.3 in)
Longer than the 30 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, 30 years of values from 1949 to 1980.
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 1961; 78.7 mm (3.1 in) in 1974; 74.9 mm (2.9 in) in 1968.
Download the Data
Data for Lonesome Lake standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Lonesome Lake 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.