Colville AP Weather Records (USC00451650)

Record envelope, standing records and threshold days for Colville AP (USC00451650), Washington, United States, with 51 years of record.

Key Facts for Colville AP

Colville AP (USC00451650) is a weather station in Washington, United States at 48.55 latitude and -117.88 longitude, 575 m (1,885 ft) above sea level.
The station reports from 1937 to 1987, 51 years of record.
1,464 records set at Colville AP still stand.
Records are tracked for tmax, tmin, prcp, snow, snwd: an element needs 30 years of data to be eligible.
Colville AP set a daily record low maximum temperature of 8.9 C (48.0 F) on 14 October 1987.

About the Station

Location: Washington, United States, 48.55 latitude, -117.88 longitude.
Elevation: 575 m (1,885 ft).
Period of record: 1937 to 1987, 51 years.
Eligible elements: tmax, tmin, prcp, snow, snwd.

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 Colville AP. 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 Colville AP, with 2026 drawn through them
Month	Highest record high	Lowest record low	2026 highest maximum	2026 lowest minimum
Jan	11.7 C (53.1 F)	-31.1 C (-24.0 F)	n/a	n/a
Feb	16.7 C (62.1 F)	-31.1 C (-24.0 F)	n/a	n/a
Mar	22.2 C (72.0 F)	-20.6 C (-5.1 F)	n/a	n/a
Apr	32.8 C (91.0 F)	-7.8 C (18.0 F)	n/a	n/a
May	35.6 C (96.1 F)	-6.7 C (19.9 F)	n/a	n/a
Jun	37.2 C (99.0 F)	-1.1 C (30.0 F)	n/a	n/a
Jul	41.7 C (107.1 F)	0.6 C (33.1 F)	n/a	n/a
Aug	41.7 C (107.1 F)	0.6 C (33.1 F)	n/a	n/a
Sep	37.2 C (99.0 F)	-5.0 C (23.0 F)	n/a	n/a
Oct	29.4 C (84.9 F)	-13.3 C (8.1 F)	n/a	n/a
Nov	19.4 C (66.9 F)	-26.7 C (-16.1 F)	n/a	n/a
Dec	14.4 C (57.9 F)	-36.1 C (-33.0 F)	n/a	n/a

Which Years Hold Standing Records

1,464 standing records

1,464 records at Colville AP still stand. 1950 holds the most, with 53.

Standing records at Colville AP by the year they were set
Year set	Standing records
1937	33
1938	37
1939	5
1940	29
1941	28
1942	26
1943	40
1944	30
1945	28
1946	15
1947	38
1948	28
1949	42
1950	53
1951	26
1952	34
1953	40
1954	36
1955	53
1956	31
1957	27
1958	31
1959	15
1960	30
1961	25
1962	37
1963	29
1964	29
1965	32
1966	23
1967	33
1968	35
1969	17
1970	18
1971	23
1972	37
1973	15
1974	29
1975	29
1976	14
1977	22
1978	6
1979	30
1980	22
1981	19
1982	26
1983	30
1984	33
1985	39
1986	23
1987	34

All-Time Record Progression

4 new records

4 all-time records were set at Colville AP between 29 December 1968 and 15 February 1986. Each dot is a new record.

When Colville AP set new all-time records
Date	Kind	Detail
1968-12-29	Record low maximum temperature	Record low maximum temperature -22.8 C (-9.0 F)
1968-12-29	Record low minimum temperature	Record low minimum temperature -32.2 C (-26.0 F)
1968-12-30	Record low minimum temperature	Record low minimum temperature -36.1 C (-33.0 F)
1986-02-15	Record daily snowfall	Record daily snowfall 36.3 cm (14.3 in)

Wettest Day of Each Month

May: 46.7 mm (1.8 in)

The wettest day on record for each calendar month at Colville AP. The most was 46.7 mm (1.8 in) on 26 May 1942.

Record daily precipitation for each month at Colville AP
Month	Record daily precipitation (mm)	Date
Jan	36.6 mm (1.4 in)	7 January 1962
Feb	30.7 mm (1.2 in)	15 February 1986
Mar	26.4 mm (1.0 in)	1 March 1982
Apr	30.0 mm (1.2 in)	28 April 1953
May	46.7 mm (1.8 in)	26 May 1942
Jun	43.9 mm (1.7 in)	21 June 1984
Jul	33.3 mm (1.3 in)	20 July 1981
Aug	27.4 mm (1.1 in)	26 August 1941
Sep	26.7 mm (1.1 in)	20 September 1945
Oct	29.5 mm (1.2 in)	1 October 1940
Nov	32.8 mm (1.3 in)	11 November 1968
Dec	24.4 mm (1.0 in)	18 December 1951

Period of Record Coverage

1937 to 1987

51 years of record at Colville AP, 1937 to 1987. 6 years have data for under 90 percent of days and are left out of rankings: 1937, 1939, 1949, 1950, 1978, 1987.

Days with data per year at Colville AP
Year	Days with data	Share of year	Complete
1937	305	84%	No
1938	362	99%	Yes
1939	31	8%	No
1940	366	100%	Yes
1941	346	95%	Yes
1942	350	96%	Yes
1943	365	100%	Yes
1944	363	99%	Yes
1945	362	99%	Yes
1946	365	100%	Yes
1947	364	100%	Yes
1948	332	91%	Yes
1949	298	82%	No
1950	324	89%	No
1951	348	95%	Yes
1952	363	99%	Yes
1953	355	97%	Yes
1954	363	99%	Yes
1955	364	100%	Yes
1956	366	100%	Yes
1957	353	97%	Yes
1958	363	99%	Yes
1959	361	99%	Yes
1960	364	99%	Yes
1961	351	96%	Yes
1962	358	98%	Yes
1963	363	99%	Yes
1964	366	100%	Yes
1965	363	99%	Yes
1966	364	100%	Yes
1967	365	100%	Yes
1968	365	100%	Yes
1969	365	100%	Yes
1970	365	100%	Yes
1971	365	100%	Yes
1972	365	100%	Yes
1973	365	100%	Yes
1974	363	99%	Yes
1975	354	97%	Yes
1976	359	98%	Yes
1977	346	95%	Yes
1978	303	83%	No
1979	364	100%	Yes
1980	347	95%	Yes
1981	362	99%	Yes
1982	359	98%	Yes
1983	360	99%	Yes
1984	353	96%	Yes
1985	358	98%	Yes
1986	360	99%	Yes
1987	298	82%	No

Latest Records

Latest records at Colville AP
Date	Station	Record	Value	Beat old record by	Old record stood	Significance
14 October 1987	Colville AP, US	daily low max	8.9 C (48.0 F)	1.1 C (2.0 F)	40 years	19 of 100 (Routine)
8 October 1987	Colville AP, US	daily high min (Tie)	8.3 C (46.9 F)	tie	8 years	1 of 100 (Routine)
13 September 1987	Colville AP, US	daily high min	15.0 C (59.0 F)	1.1 C (2.0 F)	42 years	19 of 100 (Routine)
13 August 1987	Colville AP, US	daily rain	5.8 mm (0.23 in)	0.7 mm (0.03 in)	4 years	7 of 100 (Routine)
10 August 1987	Colville AP, US	daily high min (Tie)	17.8 C (64.0 F)	tie	42 years	4 of 100 (Routine)
9 August 1987	Colville AP, US	daily high max (Tie)	37.2 C (99.0 F)	tie	44 years	4 of 100 (Routine)
25 July 1987	Colville AP, US	daily rain	18.5 mm (0.7 in)	3.8 mm (0.15 in)	8 years	14 of 100 (Routine)
19 July 1987	Colville AP, US	daily low max	20.6 C (69.1 F)	2.7 C (4.9 F)	36 years	21 of 100 (Routine)
18 July 1987	Colville AP, US	daily low max	20.0 C (68.0 F)	2.2 C (4.0 F)	14 years	13 of 100 (Routine)
9 July 1987	Colville AP, US	daily low max	18.3 C (64.9 F)	1.7 C (3.1 F)	14 years	12 of 100 (Routine)
3 July 1987	Colville AP, US	daily high min	17.2 C (63.0 F)	1.1 C (2.0 F)	44 years	21 of 100 (Routine)
2 July 1987	Colville AP, US	daily high min	17.8 C (64.0 F)	1.1 C (2.0 F)	24 years	15 of 100 (Routine)
1 July 1987	Colville AP, US	daily high max	36.1 C (97.0 F)	0.5 C (0.9 F)	44 years	19 of 100 (Routine)
1 July 1987	Colville AP, US	daily high min	16.7 C (62.1 F)	1.7 C (3.1 F)	4 years	11 of 100 (Routine)
28 June 1987	Colville AP, US	daily high min	15.0 C (59.0 F)	1.1 C (2.0 F)	4 years	9 of 100 (Routine)
28 June 1987	Colville AP, US	daily high max (Tie)	33.3 C (91.9 F)	tie	49 years	4 of 100 (Routine)
27 June 1987	Colville AP, US	daily high max	35.0 C (95.0 F)	1.7 C (3.1 F)	13 years	12 of 100 (Routine)
26 June 1987	Colville AP, US	daily high max	34.4 C (93.9 F)	1.1 C (2.0 F)	8 years	9 of 100 (Routine)
19 June 1987	Colville AP, US	daily high min (Tie)	16.1 C (61.0 F)	tie	24 years	3 of 100 (Routine)
15 June 1987	Colville AP, US	daily rain	33.5 mm (1.3 in)	22.8 mm (0.9 in)	4 years	46 of 100 (Notable)

Climate Trend

39 complete years, 1938 to 1986

One stripe for each of 39 complete years at Colville AP, 1938 to 1986. Blue stripes are years cooler than the station's own mean of 8.0 C (46.4 F); red stripes are warmer. The coolest year was 1955, at 6.5 C (43.8 F), and the warmest was 1958, at 9.5 C (49.1 F). The strongest colour marks a difference of 1.6 C (2.9 F).

Annual mean temperature at Colville AP as warming stripes, 1938 to 1986
Year	Annual mean temperature	Difference from the station mean
1938	8.9 C	+0.90 C
1940	9.1 C	+1.10 C
1943	7.3 C	-0.69 C
1944	8.2 C	+0.23 C
1945	8.1 C	+0.13 C
1946	7.9 C	-0.12 C
1947	8.3 C	+0.27 C
1951	7.3 C	-0.66 C
1952	8.4 C	+0.44 C
1953	9.0 C	+1.05 C
1954	7.7 C	-0.26 C
1955	6.5 C	-1.45 C
1956	7.8 C	-0.15 C
1957	7.3 C	-0.68 C
1958	9.5 C	+1.51 C
1959	7.5 C	-0.53 C
1960	8.0 C	-0.01 C
1962	8.0 C	-0.03 C
1963	8.5 C	+0.48 C
1964	6.8 C	-1.22 C
1965	7.9 C	-0.13 C
1966	8.5 C	+0.50 C
1967	8.9 C	+0.94 C
1968	7.8 C	-0.21 C
1969	7.6 C	-0.42 C
1970	7.8 C	-0.16 C
1971	7.4 C	-0.59 C
1972	7.4 C	-0.64 C
1973	8.5 C	+0.52 C
1974	8.4 C	+0.45 C
1975	7.1 C	-0.90 C
1976	7.3 C	-0.65 C
1979	8.2 C	+0.19 C
1981	8.8 C	+0.82 C
1982	8.0 C	+0.04 C
1983	8.6 C	+0.56 C
1984	7.5 C	-0.51 C
1985	7.0 C	-1.01 C
1986	9.0 C	+1.05 C

The fitted trend in annual mean temperature here over 1938 to 1986 is -0.1 C (-0.2 to 0.1) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.1 F (-0.4 to 0.2) per decade. The slope is a straight line fitted to 39 complete years; the brackets give its 95 percent interval.

Fitted temperature trends per decade at Colville AP
Measure	Per decade (C)	Per decade (F)	Period	Complete years	Reading
Annual mean temperature	-0.1 C (-0.2 to 0.1) per decade	-0.1 F (-0.4 to 0.2) per decade	1938 to 1986	39	Not clearly different from zero
Mean daily maximum	-0.21 C (-0.40 to -0.02) per decade	-0.38 F (-0.72 to -0.03) per decade	1938 to 1986	39	Fall
Mean daily minimum	0.1 C (-0.1 to 0.3) per decade	0.2 F (-0.2 to 0.5) per decade	1938 to 1986	39	Not clearly different from zero

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

1937 to 1987

Yearly extremes at Colville AP: the record and the median year
Measure	Record	Year of the record	Median year	Years with a value
Hottest day (TXx)	41.7 C (107.1 F)	1941	37.2 C (99.0 F)	51
Coldest night (TNn)	-36.1 C (-33.0 F)	1968	-23.9 C (-11.0 F)	51
Wettest day (Rx1day)	46.7 mm (1.8 in)	1942	23.6 mm (0.9 in)	51
Wettest five days (Rx5day)	92.8 mm (3.7 in)	1942	43.4 mm (1.7 in)	51
Longest dry spell (CDD)	75 days	1942	32 days	51

Hottest day (TXx)

The hottest day of the year at Colville AP, 1937 to 1987. The record is 41.7 C (107.1 F) in 1941, marked on the chart; the median year is 37.2 C (99.0 F).

Hottest day (TXx) at Colville AP by year
Year	Hottest day (TXx)
1937	36.7 C (98.1 F)
1938	40.0 C (104.0 F)
1939	8.3 C (46.9 F)
1940	38.9 C (102.0 F)
1941	41.7 C (107.1 F)
1942	37.8 C (100.0 F)
1943	37.2 C (99.0 F)
1944	37.8 C (100.0 F)
1945	36.7 C (98.1 F)
1946	37.8 C (100.0 F)
1947	37.2 C (99.0 F)
1948	33.9 C (93.0 F)
1949	37.2 C (99.0 F)
1950	37.2 C (99.0 F)
1951	37.8 C (100.0 F)
1952	38.9 C (102.0 F)
1953	37.2 C (99.0 F)
1954	35.0 C (95.0 F)
1955	36.7 C (98.1 F)
1956	37.8 C (100.0 F)
1957	35.0 C (95.0 F)
1958	38.3 C (100.9 F)
1959	38.9 C (102.0 F)
1960	41.7 C (107.1 F)
1961	41.7 C (107.1 F)
1962	37.8 C (100.0 F)
1963	36.7 C (98.1 F)
1964	37.2 C (99.0 F)
1965	37.2 C (99.0 F)
1966	37.2 C (99.0 F)
1967	40.0 C (104.0 F)
1968	38.3 C (100.9 F)
1969	37.8 C (100.0 F)
1970	38.3 C (100.9 F)
1971	38.3 C (100.9 F)
1972	38.9 C (102.0 F)
1973	38.3 C (100.9 F)
1974	36.7 C (98.1 F)
1975	38.9 C (102.0 F)
1976	35.0 C (95.0 F)
1977	37.2 C (99.0 F)
1978	36.1 C (97.0 F)
1979	39.4 C (102.9 F)
1980	36.1 C (97.0 F)
1981	35.6 C (96.1 F)
1982	37.2 C (99.0 F)
1983	35.6 C (96.1 F)
1984	36.7 C (98.1 F)
1985	38.3 C (100.9 F)
1986	36.7 C (98.1 F)
1987	37.2 C (99.0 F)

Coldest night (TNn)

The coldest night of the year at Colville AP, 1937 to 1987. The record is -36.1 C (-33.0 F) in 1968, marked on the chart; the median year is -23.9 C (-11.0 F).

Coldest night (TNn) at Colville AP by year
Year	Coldest night (TNn)
1937	-12.2 C (10.0 F)
1938	-16.7 C (1.9 F)
1939	-15.6 C (3.9 F)
1940	-16.7 C (1.9 F)
1941	-15.0 C (5.0 F)
1942	-21.1 C (-6.0 F)
1943	-31.1 C (-24.0 F)
1944	-18.9 C (-2.0 F)
1945	-16.7 C (1.9 F)
1946	-20.0 C (-4.0 F)
1947	-22.2 C (-8.0 F)
1948	-25.6 C (-14.1 F)
1949	-27.8 C (-18.0 F)
1950	-31.1 C (-24.0 F)
1951	-24.4 C (-11.9 F)
1952	-28.9 C (-20.0 F)
1953	-8.3 C (17.1 F)
1954	-28.9 C (-20.0 F)
1955	-23.3 C (-9.9 F)
1956	-25.6 C (-14.1 F)
1957	-30.6 C (-23.1 F)
1958	-20.6 C (-5.1 F)
1959	-24.4 C (-11.9 F)
1960	-23.9 C (-11.0 F)
1961	-24.4 C (-11.9 F)
1962	-29.4 C (-20.9 F)
1963	-21.7 C (-7.1 F)
1964	-30.0 C (-22.0 F)
1965	-16.7 C (1.9 F)
1966	-17.8 C (0.0 F)
1967	-18.3 C (-0.9 F)
1968	-36.1 C (-33.0 F)
1969	-31.1 C (-24.0 F)
1970	-22.2 C (-8.0 F)
1971	-22.8 C (-9.0 F)
1972	-24.4 C (-11.9 F)
1973	-21.1 C (-6.0 F)
1974	-25.6 C (-14.1 F)
1975	-24.4 C (-11.9 F)
1976	-19.4 C (-2.9 F)
1977	-20.6 C (-5.1 F)
1978	-30.0 C (-22.0 F)
1979	-30.0 C (-22.0 F)
1980	-26.1 C (-15.0 F)
1981	-15.0 C (5.0 F)
1982	-25.6 C (-14.1 F)
1983	-27.8 C (-18.0 F)
1984	-25.0 C (-13.0 F)
1985	-26.7 C (-16.1 F)
1986	-16.7 C (1.9 F)
1987	-13.3 C (8.1 F)

Wettest day (Rx1day)

The wettest day of the year at Colville AP, 1937 to 1987. The record is 46.7 mm (1.8 in) in 1942, marked on the chart; the median year is 23.6 mm (0.9 in).

Wettest day (Rx1day) at Colville AP by year
Year	Wettest day (Rx1day)
1937	24.9 mm (1.0 in)
1938	23.1 mm (0.9 in)
1939	12.7 mm (0.5 in)
1940	29.5 mm (1.2 in)
1941	27.4 mm (1.1 in)
1942	46.7 mm (1.8 in)
1943	25.4 mm (1.0 in)
1944	17.3 mm (0.7 in)
1945	26.7 mm (1.1 in)
1946	20.3 mm (0.8 in)
1947	17.5 mm (0.7 in)
1948	22.9 mm (0.9 in)
1949	24.4 mm (1.0 in)
1950	24.6 mm (1.0 in)
1951	24.9 mm (1.0 in)
1952	24.4 mm (1.0 in)
1953	30.0 mm (1.2 in)
1954	22.6 mm (0.9 in)
1955	18.3 mm (0.7 in)
1956	21.8 mm (0.9 in)
1957	29.7 mm (1.2 in)
1958	17.0 mm (0.7 in)
1959	21.3 mm (0.8 in)
1960	23.1 mm (0.9 in)
1961	20.8 mm (0.8 in)
1962	36.6 mm (1.4 in)
1963	17.0 mm (0.7 in)
1964	18.3 mm (0.7 in)
1965	23.6 mm (0.9 in)
1966	24.9 mm (1.0 in)
1967	18.8 mm (0.7 in)
1968	32.8 mm (1.3 in)
1969	18.5 mm (0.7 in)
1970	23.1 mm (0.9 in)
1971	18.5 mm (0.7 in)
1972	21.1 mm (0.8 in)
1973	26.2 mm (1.0 in)
1974	27.2 mm (1.1 in)
1975	24.9 mm (1.0 in)
1976	25.9 mm (1.0 in)
1977	17.0 mm (0.7 in)
1978	23.6 mm (0.9 in)
1979	17.5 mm (0.7 in)
1980	18.8 mm (0.7 in)
1981	33.3 mm (1.3 in)
1982	26.4 mm (1.0 in)
1983	21.8 mm (0.9 in)
1984	43.9 mm (1.7 in)
1985	22.4 mm (0.9 in)
1986	30.7 mm (1.2 in)
1987	33.5 mm (1.3 in)

Wettest five days (Rx5day)

The wettest five days of the year at Colville AP, 1937 to 1987. The record is 92.8 mm (3.7 in) in 1942, marked on the chart; the median year is 43.4 mm (1.7 in).

Wettest five days (Rx5day) at Colville AP by year
Year	Wettest five days (Rx5day)
1937	40.4 mm (1.6 in)
1938	40.1 mm (1.6 in)
1939	22.1 mm (0.9 in)
1940	47.5 mm (1.9 in)
1941	55.6 mm (2.2 in)
1942	92.8 mm (3.7 in)
1943	33.3 mm (1.3 in)
1944	24.9 mm (1.0 in)
1945	39.4 mm (1.6 in)
1946	42.7 mm (1.7 in)
1947	45.2 mm (1.8 in)
1948	45.8 mm (1.8 in)
1949	35.3 mm (1.4 in)
1950	33.4 mm (1.3 in)
1951	49.6 mm (2.0 in)
1952	29.5 mm (1.2 in)
1953	43.7 mm (1.7 in)
1954	28.3 mm (1.1 in)
1955	42.4 mm (1.7 in)
1956	40.1 mm (1.6 in)
1957	55.7 mm (2.2 in)
1958	54.9 mm (2.2 in)
1959	59.9 mm (2.4 in)
1960	41.2 mm (1.6 in)
1961	46.0 mm (1.8 in)
1962	50.3 mm (2.0 in)
1963	33.7 mm (1.3 in)
1964	41.1 mm (1.6 in)
1965	50.3 mm (2.0 in)
1966	60.8 mm (2.4 in)
1967	33.3 mm (1.3 in)
1968	52.1 mm (2.1 in)
1969	43.5 mm (1.7 in)
1970	33.8 mm (1.3 in)
1971	35.0 mm (1.4 in)
1972	43.4 mm (1.7 in)
1973	72.2 mm (2.8 in)
1974	60.3 mm (2.4 in)
1975	48.8 mm (1.9 in)
1976	39.8 mm (1.6 in)
1977	36.3 mm (1.4 in)
1978	49.7 mm (2.0 in)
1979	30.5 mm (1.2 in)
1980	54.8 mm (2.2 in)
1981	40.7 mm (1.6 in)
1982	44.0 mm (1.7 in)
1983	44.7 mm (1.8 in)
1984	63.1 mm (2.5 in)
1985	31.8 mm (1.3 in)
1986	46.0 mm (1.8 in)
1987	41.2 mm (1.6 in)

Longest dry spell (CDD)

The longest dry spell of the year at Colville AP, 1937 to 1987. The record is 75 days in 1942, marked on the chart; the median year is 32 days.

Longest dry spell (CDD) at Colville AP by year
Year	Longest dry spell (CDD)
1937	21 days
1938	40 days
1939	8 days
1940	43 days
1941	30 days
1942	75 days
1943	48 days
1944	33 days
1945	26 days
1946	52 days
1947	24 days
1948	29 days
1949	37 days
1950	32 days
1951	52 days
1952	49 days
1953	32 days
1954	21 days
1955	46 days
1956	30 days
1957	39 days
1958	29 days
1959	37 days
1960	32 days
1961	21 days
1962	49 days
1963	32 days
1964	22 days
1965	25 days
1966	27 days
1967	58 days
1968	24 days
1969	72 days
1970	31 days
1971	24 days
1972	33 days
1973	39 days
1974	39 days
1975	34 days
1976	25 days
1977	39 days
1978	18 days
1979	43 days
1980	21 days
1981	21 days
1982	15 days
1983	28 days
1984	26 days
1985	54 days
1986	31 days
1987	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

39 years with a frost

Across 39 years with a frost, the median last spring frost at Colville AP falls on 14 May and the median first autumn frost on 21 September, which leaves a median of 134 days between them.

Fitted over all years, the growing season changes by -2.5 days per decade at this station.

Frost dates and growing season at Colville AP
Measure	Median, all years	Earliest period	Recent period (1953 to 1986)	Recent against earliest	Fitted trend
Last spring frost	14 May	n/a	15 May	n/a	+0.4 days per decade
First autumn frost	21 September	n/a	20 September	n/a	-2.2 days per decade
Growing days	134 days	n/a	133 days	n/a	-2.5 days per decade

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

45 years, 1938 to 1986

A day with at least 23.0 mm (0.9 in) of rain is expected about once in 2 years. A day with at least 48.6 mm (1.9 in) of rain is expected about once in 100 years.

Rainfall return levels at Colville AP: the daily rain expected about once in a given number of years
Expected about once in	A day with at least	Note
2 years	23.0 mm (0.9 in)
5 years	28.6 mm (1.1 in)
10 years	32.8 mm (1.3 in)
25 years	38.7 mm (1.5 in)
50 years	43.5 mm (1.7 in)	Longer than the 45 years of record
100 years	48.6 mm (1.9 in)	Longer than the 45 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, 45 years of values from 1938 to 1986.

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: 46.7 mm (1.8 in) in 1942; 43.9 mm (1.7 in) in 1984; 36.6 mm (1.4 in) in 1962.

Download the Data

Data for Colville AP standing records by year: CSV or JSON. Field meanings are on the data page.
Data for Colville AP 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).