Record envelope, standing records and threshold days for China Flat (USC00041731), California, United States, with 48 years of record.
Key Facts for China Flat
China Flat (USC00041731) is a weather station in California, United States at 40.87 latitude and -123.58 longitude, 183 m (600 ft) above sea level.
The station reports from 1908 to 1955, 48 years of record.
1,464 records set at China Flat still stand.
Records are tracked for tmax, tmin, prcp: an element needs 30 years of data to be eligible.
China Flat tied a daily record high minimum temperature of 15.0 C (59.0 F) on 11 June 1955.
About the Station
Location: California, United States, 40.87 latitude, -123.58 longitude.
Elevation: 183 m (600 ft).
Period of record: 1908 to 1955, 48 years.
Eligible elements: tmax, tmin, prcp.
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 China Flat. 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 China Flat, with 2026 drawn through them
Month
Highest record high
Lowest record low
2026 highest maximum
2026 lowest minimum
Jan
21.7 C (71.1 F)
-12.2 C (10.0 F)
n/a
n/a
Feb
22.8 C (73.0 F)
-8.3 C (17.1 F)
n/a
n/a
Mar
31.1 C (88.0 F)
-5.0 C (23.0 F)
n/a
n/a
Apr
36.7 C (98.1 F)
-2.2 C (28.0 F)
n/a
n/a
May
41.1 C (106.0 F)
-0.6 C (30.9 F)
n/a
n/a
Jun
41.7 C (107.1 F)
1.7 C (35.1 F)
n/a
n/a
Jul
45.0 C (113.0 F)
4.4 C (39.9 F)
n/a
n/a
Aug
44.4 C (111.9 F)
4.4 C (39.9 F)
n/a
n/a
Sep
40.6 C (105.1 F)
0.0 C (32.0 F)
n/a
n/a
Oct
33.9 C (93.0 F)
-3.9 C (25.0 F)
n/a
n/a
Nov
26.7 C (80.1 F)
-8.3 C (17.1 F)
n/a
n/a
Dec
19.4 C (66.9 F)
-12.8 C (9.0 F)
n/a
n/a
Which Years Hold Standing Records
1,464 standing records
Year with most
1,464 records at China Flat still stand. 1909 holds the most, with 73.
Standing records at China Flat by the year they were set
Year set
Standing records
1908
13
1909
73
1910
66
1911
37
1912
40
1913
49
1914
35
1915
19
1916
42
1917
36
1918
32
1919
25
1920
35
1921
8
1922
19
1923
18
1924
32
1925
35
1926
37
1927
18
1928
26
1929
49
1930
23
1931
41
1932
53
1933
30
1934
29
1935
44
1936
50
1937
32
1938
31
1939
27
1940
29
1941
33
1942
19
1943
20
1944
20
1945
23
1946
14
1947
22
1948
23
1949
26
1950
36
1951
17
1952
19
1953
32
1954
11
1955
16
Wettest Day of Each Month
Feb: 180.6 mm (7.1 in)
The wettest day on record for each calendar month at China Flat. The most was 180.6 mm (7.1 in) on 1 February 1915.
Record daily precipitation for each month at China Flat
Month
Record daily precipitation (mm)
Date
Jan
99.6 mm (3.9 in)
24 January 1912
Feb
180.6 mm (7.1 in)
1 February 1915
Mar
69.1 mm (2.7 in)
26 March 1928
Apr
76.2 mm (3.0 in)
18 April 1925
May
45.5 mm (1.8 in)
25 May 1942
Jun
25.7 mm (1.0 in)
14 June 1931
Jul
18.5 mm (0.7 in)
12 July 1952
Aug
25.1 mm (1.0 in)
18 August 1924
Sep
59.9 mm (2.4 in)
5 September 1912
Oct
80.0 mm (3.1 in)
29 October 1950
Nov
94.5 mm (3.7 in)
20 November 1909
Dec
116.1 mm (4.6 in)
2 December 1941
Period of Record Coverage
1908 to 1955
Complete yearUnder 90 percent of days
48 years of record at China Flat, 1908 to 1955. 3 years have data for under 90 percent of days and are left out of rankings: 1908, 1952, 1955.
Cooler than the station meanWarmer than the station mean
One stripe for each of 42 complete years at China Flat, 1909 to 1954. Blue stripes are years cooler than the station's own mean of 13.7 C (56.7 F); red stripes are warmer. The coolest year was 1916, at 12.5 C (54.5 F), and the warmest was 1910, at 15.4 C (59.8 F). The strongest colour marks a difference of 1.8 C (3.2 F).
Annual mean temperature at China Flat as warming stripes, 1909 to 1954
Year
Annual mean temperature
Difference from the station mean
1909
14.8 C
+1.06 C
1910
15.4 C
+1.72 C
1911
13.8 C
+0.08 C
1913
14.4 C
+0.68 C
1914
14.8 C
+1.05 C
1915
14.2 C
+0.47 C
1916
12.5 C
-1.20 C
1917
12.9 C
-0.80 C
1918
13.3 C
-0.39 C
1919
13.2 C
-0.55 C
1920
13.1 C
-0.66 C
1921
13.7 C
-0.01 C
1922
13.2 C
-0.56 C
1923
13.1 C
-0.58 C
1924
13.9 C
+0.15 C
1925
13.8 C
+0.03 C
1926
14.7 C
+0.94 C
1927
13.1 C
-0.58 C
1928
13.2 C
-0.50 C
1929
12.7 C
-1.02 C
1930
13.1 C
-0.67 C
1931
14.0 C
+0.28 C
1932
13.4 C
-0.35 C
1933
13.2 C
-0.52 C
1934
14.7 C
+0.94 C
1935
12.7 C
-1.00 C
1936
13.0 C
-0.71 C
1938
13.7 C
-0.01 C
1939
14.5 C
+0.77 C
1940
14.7 C
+1.01 C
1941
14.2 C
+0.52 C
1942
13.8 C
+0.03 C
1943
14.2 C
+0.48 C
1944
13.8 C
+0.07 C
1945
14.2 C
+0.49 C
1946
13.3 C
-0.45 C
1947
13.7 C
-0.04 C
1949
12.9 C
-0.79 C
1950
13.8 C
+0.08 C
1951
14.1 C
+0.38 C
1953
13.9 C
+0.22 C
1954
13.8 C
+0.05 C
The fitted trend in annual mean temperature here over 1909 to 1954 is -0.03 C (-0.19 to 0.14) per decade. The interval includes zero, so the trend is not clearly different from zero. In Fahrenheit: -0.05 F (-0.35 to 0.25) per decade. The slope is a straight line fitted to 42 complete years; the brackets give its 95 percent interval.
Fitted temperature trends per decade at China Flat
Measure
Per decade (C)
Per decade (F)
Period
Complete years
Reading
Annual mean temperature
-0.03 C (-0.19 to 0.14) per decade
-0.05 F (-0.35 to 0.25) per decade
1909 to 1954
42
Not clearly different from zero
Mean daily maximum
0.1 C (-0.2 to 0.4) per decade
0.2 F (-0.4 to 0.7) per decade
1909 to 1954
42
Not clearly different from zero
Mean daily minimum
-0.1 C (-0.4 to 0.1) per decade
-0.3 F (-0.6 to 0.1) per decade
1909 to 1954
42
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
1908 to 1955
Yearly extremes at China Flat: the record and the median year
Measure
Record
Year of the record
Median year
Years with a value
Hottest day (TXx)
45.0 C (113.0 F)
1910
39.7 C (103.5 F)
48
Coldest night (TNn)
-12.8 C (9.0 F)
1932
-6.4 C (20.5 F)
48
Wettest day (Rx1day)
180.6 mm (7.1 in)
1915
64.8 mm (2.6 in)
47
Wettest five days (Rx5day)
277.9 mm (10.9 in)
1915
160.5 mm (6.3 in)
47
Longest dry spell (CDD)
144 days
1938
71 days
47
Hottest day (TXx)
The hottest day of the year at China Flat, 1908 to 1955. The record is 45.0 C (113.0 F) in 1910, marked on the chart; the median year is 39.7 C (103.5 F).
Hottest day (TXx) at China Flat by year
Year
Hottest day (TXx)
1908
39.4 C (102.9 F)
1909
41.1 C (106.0 F)
1910
45.0 C (113.0 F)
1911
44.4 C (111.9 F)
1912
40.0 C (104.0 F)
1913
41.1 C (106.0 F)
1914
42.2 C (108.0 F)
1915
43.3 C (109.9 F)
1916
36.1 C (97.0 F)
1917
39.4 C (102.9 F)
1918
37.8 C (100.0 F)
1919
37.8 C (100.0 F)
1920
38.9 C (102.0 F)
1921
36.1 C (97.0 F)
1922
38.3 C (100.9 F)
1923
37.2 C (99.0 F)
1924
38.9 C (102.0 F)
1925
38.9 C (102.0 F)
1926
38.3 C (100.9 F)
1927
35.0 C (95.0 F)
1928
35.0 C (95.0 F)
1929
41.1 C (106.0 F)
1930
36.1 C (97.0 F)
1931
42.2 C (108.0 F)
1932
44.4 C (111.9 F)
1933
42.8 C (109.0 F)
1934
40.6 C (105.1 F)
1935
41.7 C (107.1 F)
1936
39.4 C (102.9 F)
1937
40.0 C (104.0 F)
1938
42.2 C (108.0 F)
1939
42.2 C (108.0 F)
1940
41.1 C (106.0 F)
1941
39.4 C (102.9 F)
1942
41.7 C (107.1 F)
1943
38.9 C (102.0 F)
1944
40.0 C (104.0 F)
1945
41.7 C (107.1 F)
1946
42.8 C (109.0 F)
1947
37.8 C (100.0 F)
1948
38.3 C (100.9 F)
1949
39.4 C (102.9 F)
1950
40.0 C (104.0 F)
1951
40.6 C (105.1 F)
1952
40.0 C (104.0 F)
1953
39.4 C (102.9 F)
1954
39.4 C (102.9 F)
1955
38.9 C (102.0 F)
Coldest night (TNn)
The coldest night of the year at China Flat, 1908 to 1955. The record is -12.8 C (9.0 F) in 1932, marked on the chart; the median year is -6.4 C (20.5 F).
Coldest night (TNn) at China Flat by year
Year
Coldest night (TNn)
1908
-6.1 C (21.0 F)
1909
-2.8 C (27.0 F)
1910
-7.8 C (18.0 F)
1911
-6.7 C (19.9 F)
1912
-4.4 C (24.1 F)
1913
-8.9 C (16.0 F)
1914
-5.6 C (21.9 F)
1915
-6.7 C (19.9 F)
1916
-6.7 C (19.9 F)
1917
-10.0 C (14.0 F)
1918
-6.7 C (19.9 F)
1919
-8.3 C (17.1 F)
1920
-5.0 C (23.0 F)
1921
-4.4 C (24.1 F)
1922
-7.8 C (18.0 F)
1923
-5.6 C (21.9 F)
1924
-7.2 C (19.0 F)
1925
-0.6 C (30.9 F)
1926
-1.1 C (30.0 F)
1927
-5.6 C (21.9 F)
1928
-8.3 C (17.1 F)
1929
-8.3 C (17.1 F)
1930
-8.9 C (16.0 F)
1931
-7.2 C (19.0 F)
1932
-12.8 C (9.0 F)
1933
-5.6 C (21.9 F)
1934
-2.2 C (28.0 F)
1935
-6.7 C (19.9 F)
1936
-8.9 C (16.0 F)
1937
-12.2 C (10.0 F)
1938
-5.0 C (23.0 F)
1939
-3.9 C (25.0 F)
1940
-10.0 C (14.0 F)
1941
-5.6 C (21.9 F)
1942
-4.4 C (24.1 F)
1943
-6.7 C (19.9 F)
1944
-2.2 C (28.0 F)
1945
-5.0 C (23.0 F)
1946
-4.4 C (24.1 F)
1947
-7.2 C (19.0 F)
1948
-7.8 C (18.0 F)
1949
-11.1 C (12.0 F)
1950
-7.8 C (18.0 F)
1951
-5.6 C (21.9 F)
1952
-5.6 C (21.9 F)
1953
-4.4 C (24.1 F)
1954
-3.9 C (25.0 F)
1955
-3.9 C (25.0 F)
Wettest day (Rx1day)
The wettest day of the year at China Flat, 1908 to 1955. The record is 180.6 mm (7.1 in) in 1915, marked on the chart; the median year is 64.8 mm (2.6 in).
Wettest day (Rx1day) at China Flat by year
Year
Wettest day (Rx1day)
1908
n/a
1909
94.5 mm (3.7 in)
1910
51.8 mm (2.0 in)
1911
57.7 mm (2.3 in)
1912
99.6 mm (3.9 in)
1913
71.6 mm (2.8 in)
1914
63.5 mm (2.5 in)
1915
180.6 mm (7.1 in)
1916
60.7 mm (2.4 in)
1917
77.5 mm (3.1 in)
1918
49.5 mm (1.9 in)
1919
65.3 mm (2.6 in)
1920
61.0 mm (2.4 in)
1921
56.1 mm (2.2 in)
1922
62.2 mm (2.4 in)
1923
32.5 mm (1.3 in)
1924
63.8 mm (2.5 in)
1925
76.2 mm (3.0 in)
1926
69.6 mm (2.7 in)
1927
101.6 mm (4.0 in)
1928
69.1 mm (2.7 in)
1929
64.3 mm (2.5 in)
1930
55.9 mm (2.2 in)
1931
48.0 mm (1.9 in)
1932
59.4 mm (2.3 in)
1933
64.8 mm (2.6 in)
1934
37.3 mm (1.5 in)
1935
47.5 mm (1.9 in)
1936
69.1 mm (2.7 in)
1937
81.5 mm (3.2 in)
1938
66.3 mm (2.6 in)
1939
82.0 mm (3.2 in)
1940
67.6 mm (2.7 in)
1941
116.1 mm (4.6 in)
1942
45.5 mm (1.8 in)
1943
94.0 mm (3.7 in)
1944
68.6 mm (2.7 in)
1945
85.1 mm (3.4 in)
1946
38.6 mm (1.5 in)
1947
45.0 mm (1.8 in)
1948
58.7 mm (2.3 in)
1949
40.1 mm (1.6 in)
1950
80.0 mm (3.1 in)
1951
67.3 mm (2.6 in)
1952
62.5 mm (2.5 in)
1953
97.3 mm (3.8 in)
1954
81.8 mm (3.2 in)
1955
43.7 mm (1.7 in)
Wettest five days (Rx5day)
The wettest five days of the year at China Flat, 1908 to 1955. The record is 277.9 mm (10.9 in) in 1915, marked on the chart; the median year is 160.5 mm (6.3 in).
Wettest five days (Rx5day) at China Flat by year
Year
Wettest five days (Rx5day)
1908
n/a
1909
206.0 mm (8.1 in)
1910
121.1 mm (4.8 in)
1911
85.7 mm (3.4 in)
1912
216.3 mm (8.5 in)
1913
208.4 mm (8.2 in)
1914
197.8 mm (7.8 in)
1915
277.9 mm (10.9 in)
1916
134.9 mm (5.3 in)
1917
185.8 mm (7.3 in)
1918
101.6 mm (4.0 in)
1919
162.0 mm (6.4 in)
1920
180.1 mm (7.1 in)
1921
94.0 mm (3.7 in)
1922
177.6 mm (7.0 in)
1923
119.7 mm (4.7 in)
1924
109.0 mm (4.3 in)
1925
131.6 mm (5.2 in)
1926
211.1 mm (8.3 in)
1927
260.4 mm (10.3 in)
1928
132.6 mm (5.2 in)
1929
141.6 mm (5.6 in)
1930
143.2 mm (5.6 in)
1931
134.7 mm (5.3 in)
1932
133.3 mm (5.2 in)
1933
177.4 mm (7.0 in)
1934
105.8 mm (4.2 in)
1935
99.8 mm (3.9 in)
1936
194.6 mm (7.7 in)
1937
159.3 mm (6.3 in)
1938
202.5 mm (8.0 in)
1939
199.1 mm (7.8 in)
1940
193.8 mm (7.6 in)
1941
171.9 mm (6.8 in)
1942
172.9 mm (6.8 in)
1943
213.7 mm (8.4 in)
1944
142.8 mm (5.6 in)
1945
146.8 mm (5.8 in)
1946
135.1 mm (5.3 in)
1947
98.6 mm (3.9 in)
1948
160.5 mm (6.3 in)
1949
112.8 mm (4.4 in)
1950
253.0 mm (10.0 in)
1951
184.2 mm (7.3 in)
1952
208.8 mm (8.2 in)
1953
249.9 mm (9.8 in)
1954
158.3 mm (6.2 in)
1955
102.1 mm (4.0 in)
Longest dry spell (CDD)
The longest dry spell of the year at China Flat, 1908 to 1955. The record is 144 days in 1938, marked on the chart; the median year is 71 days.
Longest dry spell (CDD) at China Flat by year
Year
Longest dry spell (CDD)
1908
n/a
1909
31 days
1910
111 days
1911
88 days
1912
67 days
1913
40 days
1914
73 days
1915
51 days
1916
31 days
1917
21 days
1918
47 days
1919
32 days
1920
54 days
1921
31 days
1922
56 days
1923
27 days
1924
27 days
1925
36 days
1926
85 days
1927
71 days
1928
92 days
1929
114 days
1930
101 days
1931
127 days
1932
87 days
1933
99 days
1934
89 days
1935
103 days
1936
113 days
1937
66 days
1938
144 days
1939
86 days
1940
47 days
1941
39 days
1942
74 days
1943
80 days
1944
33 days
1945
88 days
1946
48 days
1947
47 days
1948
72 days
1949
57 days
1950
76 days
1951
138 days
1952
40 days
1953
74 days
1954
72 days
1955
25 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
42 years with a frost
Across 42 years with a frost, the median last spring frost at China Flat falls on 12 March and the median first autumn frost on 5 November, which leaves a median of 238 days between them.
Fitted over all years, the growing season changes by -1.8 days per decade at this station.
Frost dates and growing season at China Flat
Measure
Median, all years
Earliest period
Recent period (1922 to 1954)
Recent against earliest
Fitted trend
Last spring frost
12 March
n/a
12 March
n/a
+0.6 days per decade
First autumn frost
5 November
n/a
5 November
n/a
-1.2 days per decade
Growing days
238 days
n/a
238 days
n/a
-1.8 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
33 years, 1910 to 1954
A day with at least 63.9 mm (2.5 in) of rain is expected about once in 2 years. A day with at least 122.5 mm (4.8 in) of rain is expected about once in 100 years.
Rainfall return levels at China Flat: the daily rain expected about once in a given number of years
Expected about once in
A day with at least
Note
2 years
63.9 mm (2.5 in)
5 years
81.0 mm (3.2 in)
10 years
91.7 mm (3.6 in)
25 years
104.6 mm (4.1 in)
50 years
113.8 mm (4.5 in)
Longer than the 33 years of record
100 years
122.5 mm (4.8 in)
Longer than the 33 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, 33 years of values from 1910 to 1954.
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: 116.1 mm (4.6 in) in 1941; 101.6 mm (4.0 in) in 1927; 99.6 mm (3.9 in) in 1912.
Station Changes
1 suspected
One change was suspected in the annual mean temperature of China Flat, at 1938. Each is measured against neighbouring stations.
Relative to 5 neighbouring stations, the station's annual mean temperature from 1938 ran 0.4 C (0.6 F) higher than in the years before (likely change).
Suspected changes in the annual mean temperature at China Flat, against neighbouring stations
Year
Shift (C)
Shift (F)
Strength
Neighbours
1938
+0.4
+0.6
likely
5
Possible change at the station (a move, a new instrument or a new site); the record is kept as measured. A "likely" change has a larger test statistic than a "possible" one. Neither says why the station differs from its neighbours. How changes are found, and the largest ones.
Download the Data
Data for China Flat standing records by year: CSV or JSON. Field meanings are on the data page.
Data for China Flat 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.