Mercersburg 1 E Threshold Days by Year (USC00365662)

18 fixed thresholds counted per year at Mercersburg 1 E (USC00365662): hot days, frost, tropical nights and heavy rain, with the most days in a year.

Key Facts for Mercersburg 1 E Thresholds

Mercersburg 1 E: days with 10 mm (0.39 in) or more of precipitation in 45 years, most in 1970 with 49.
Mercersburg 1 E: days with 25 mm (0.98 in) or more of precipitation in 45 years, most in 1973 with 17.
Mercersburg 1 E: days with 10 cm (3.9 in) or more of snowfall in 35 years, most in 1961 with 9.
Mercersburg 1 E: days with 50 mm (1.97 in) or more of precipitation in 31 years, most in 1937 with 5.
18 fixed thresholds have at least one qualifying day at Mercersburg 1 E.

Days at or above 30 C (86 F)

29 years with a qualifying day

Days per year at Mercersburg 1 E with a maximum temperature at or above 30 C (86 F), with the decade average as a line. The most was 74 in 1987.

Days at or above 30 C (86 F) per year at Mercersburg 1 E
Year	Days	Decade average
1960	39	52.6
1961	57	52.6
1962	59	52.6
1963	50	52.6
1964	52	52.6
1965	59	52.6
1966	71	52.6
1967	27	52.6
1968	58	52.6
1969	54	52.6
1970	57	40.5
1971	45	40.5
1972	39	40.5
1973	44	40.5
1974	18	40.5
1975	29	40.5
1976	43	40.5
1977	56	40.5
1978	47	40.5
1979	27	40.5
1980	65	57.9
1981	33	57.9
1982	50	57.9
1983	71	57.9
1984	45	57.9
1985	59	57.9
1986	57	57.9
1987	74	57.9
1988	67	57.9

For each year, a bar from the first to the last day at Mercersburg 1 E meeting 30 C (86 F).

First to last qualifying date each year at Mercersburg 1 E
Year	First date	Last date
1960	1960-04-24	1960-09-10
1961	1961-06-02	1961-09-26
1962	1962-04-27	1962-10-13
1963	1963-05-09	1963-10-08
1964	1964-05-20	1964-09-18
1965	1965-05-03	1965-09-23
1966	1966-06-05	1966-09-12
1967	1967-06-10	1967-10-06
1968	1968-05-04	1968-09-25
1969	1969-04-28	1969-09-18
1970	1970-05-10	1970-09-27
1971	1971-06-05	1971-09-12
1972	1972-05-25	1972-09-27
1973	1973-04-23	1973-09-06
1974	1974-04-30	1974-09-13
1975	1975-05-22	1975-08-28
1976	1976-04-17	1976-09-15
1977	1977-04-23	1977-09-20
1978	1978-05-21	1978-09-22
1979	1979-05-10	1979-09-05
1980	1980-05-25	1980-09-23
1981	1981-05-26	1981-09-15
1982	1982-05-08	1982-09-14
1983	1983-06-12	1983-09-21
1984	1984-05-21	1984-09-24
1985	1985-04-19	1985-09-22
1986	1986-04-28	1986-10-02
1987	1987-04-23	1987-09-03
1988	1988-05-14	1988-09-24

Every Fixed Threshold

Fixed thresholds at Mercersburg 1 E
Threshold	Years with a qualifying day	Most days in a year	Year	Latest year days
30 C (86 F): Days	29	74	1987	67
35 C (95 F): Days	23	28	1988	28
40 C (104 F): Days	2	2	1988	2
90 F (32.2 C): Days	29	53	1983	49
100 F (37.8 C): Days	8	14	1988	14
0 C (32 F): Ice days (max	29	39	1963	20
0 C (32 F): Frost days (min	27	158	1976	148
-10 C (14 F): Days with min	27	45	1977	31
-20 C (-4 F): Days with min	14	4	1963	2
20 C (68 F): Tropical nights (min	26	24	1968	15
25 C (77 F): Days with min	2	2	1987	1
10 mm (0.39 in): Days with 10 mm or more rain	45	49	1970	32
25 mm (0.98 in): Days with 25 mm or more rain	45	17	1973	13
50 mm (1.97 in): Days with 50 mm or more rain	31	5	1937	1
100 mm (3.94 in): Days with 100 mm or more rain	2	1	1976	1
10 cm (3.9 in): Days with 10 cm or more snowfall	35	9	1961	1
25 cm (9.8 in): Days with 25 cm or more snowfall	14	2	1961	2
50 cm (19.7 in): Days with 50 cm or more snowfall	2	1	1964	1

Years with under 90 percent of days observed are left out of the most days column. Threshold history at this station starts in 1960.

Download the Data

Data for Mercersburg 1 E 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 2025-12-31. Last revised 31 December 2025 (2025-12-31).

Mercersburg 1 E Threshold Days by Year (USC00365662)

Key Facts for Mercersburg 1 E Thresholds

Days at or above 30 C (86 F)

Every Fixed Threshold

Download the Data

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