Walnut 4S Threshold Days by Year

20 fixed thresholds counted per year at Walnut 4S (USC00148549): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Walnut 4S Thresholds

Walnut 4S: days with 10 mm (0.39 in) or more of precipitation in 99 years, most in 1985 with 50.
Walnut 4S: days with 25 mm (0.98 in) or more of precipitation in 99 years, most in 1927 with 23.
Walnut 4S: days with 50 mm (1.97 in) or more of precipitation in 92 years, most in 1994 with 10.
Walnut 4S: days with 10 cm (3.9 in) or more of snowfall in 47 years, most in 1958 with 7.
20 fixed thresholds have at least one qualifying day at Walnut 4S.

Days at or above 30 C (86 F)

12 years with a qualifying day

Days per year at Walnut 4S with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 107 in 1911.

For each year, a bar from the first to the last day at Walnut 4S meeting 30 C (86 F).

First to last qualifying date each year at Walnut 4S
Year	First date	Last date
1903	1903-06-18	1903-10-03
1904	1904-05-23	1904-10-04
1905	1905-04-08	1905-10-08
1906	1906-04-24	1906-10-04
1907	1907-03-18	1907-10-02
1908	1908-05-20	1908-09-25
1909	1909-04-18	1909-10-30
1910	1910-03-22	1910-10-15
1911	1911-04-29	1911-10-25
1913	1913-04-18	1913-09-23
1916	1916-03-13	1916-10-08
1917	1917-05-18	1917-10-16

Every Fixed Threshold

Fixed thresholds at Walnut 4S
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	12	107	1911	70
35 C (95 F): Days	12	65	1913	24
40 C (104 F): Days	7	11	1913	2
90 F (32.2 C): Days	12	85	1913	41
100 F (37.8 C): Days	9	35	1913	7
110 F (43.3 C): Days	1	1	1909	1
0 C (32 F): Ice days (max	11	30	1905	25
0 C (32 F): Frost days (min	10	112	1904	105
-10 C (14 F): Days with min	10	33	1905	31
-20 C (-4 F): Days with min	8	10	1905	7
-30 C (-22 F): Days with min	1	1	1905	1
20 C (68 F): Tropical nights (min	10	65	1911	20
25 C (77 F): Days with min	6	9	1903	2
10 mm (0.39 in): Days with 10 mm or more rain	99	50	1985	47
25 mm (0.98 in): Days with 25 mm or more rain	99	23	1927	22
50 mm (1.97 in): Days with 50 mm or more rain	92	10	1994	8
100 mm (3.94 in): Days with 100 mm or more rain	26	2	1911	1
200 mm (7.87 in): Days with 200 mm or more rain	1	1	1998	1
10 cm (3.9 in): Days with 10 cm or more snowfall	47	7	1958	2
25 cm (9.8 in): Days with 25 cm or more snowfall	4	1	1951	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1903.

Download the Data

Data for Walnut 4S 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 2026-10-17 (17 October 2026). Threshold counts are computed by this site.

Data as of 2026-10-12. Last revised 12 October 2026 (2026-10-12).

Year	Days	Decade average
1903	63	75
1904	53	75
1905	89	75
1906	71	75
1907	76	75
1908	73	75
1909	100	75
1910	80	88.6
1911	107	88.6
1913	96	88.6
1916	90	88.6
1917	70	88.6

Walnut 4S Threshold Days by Year

Key Facts for Walnut 4S Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

Related