United States · 1991–2020

Best time to visit
Derry.

September leads for comfortable weather in Derry: typically 23.8°C by day, 11.4°C at night, with 108 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high23.8°C

Typical low11.4°C

Rain in September108 mm

Comfort

September

September · June · August

77climate match

Beach

July

July · August · June

60climate match

Outdoors

October

October · May · September

72climate match

The weakest month is January, scoring 5 against September’s 77 — days reach only 3.8°C, 20° below the 24°C the score treats as ideal.

Month by month

The whole year,
without the guesswork.

The bars show the comfort score. Day and night temperatures come from daily observed highs and lows; rain is the historical monthly estimate.

Jan

53.8° / -6°

Feb

54.8° / -5.6°

Mar

59.6° / -2.3°

Apr

3617.1° / 3°

May

6121.8° / 8.4°

Jun

7326.1° / 13.9°

Jul

6628° / 16.1°

Aug

7127.5° / 15.5°

Sep

7723.8° / 11.4°

Oct

5218° / 5.1°

Nov

1411.3° / 0.5°

Dec

55.4° / -3.5°

Monthly climate evidence for Derry — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	3.8°C	-6°C	103 mm	14.3	9 h 35	5	Good coverage
February	4.8°C	-5.6°C	70 mm	11.5	10 h 36	5	Good coverage
March	9.6°C	-2.3°C	104 mm	12.9	11 h 49	5	Good coverage
April	17.1°C	3°C	107 mm	13.4	13 h 13	36	Good coverage
May	21.8°C	8.4°C	114 mm	12.3	14 h 23	61	Good coverage
June	26.1°C	13.9°C	115 mm	10.6	15 h 02	73	Good coverage
July	28°C	16.1°C	119 mm	11	14 h 47	66	Good coverage
August	27.5°C	15.5°C	113 mm	8.9	13 h 46	71	Good coverage
September	23.8°C	11.4°C	108 mm	9.1	12 h 25	77	Good coverage
October	18°C	5.1°C	73 mm	8.4	11 h 04	52	Good coverage
November	11.3°C	0.5°C	112 mm	11.8	9 h 53	14	Good coverage
December	5.4°C	-3.5°C	88 mm	12.6	9 h 18	5	Good coverage

Records at DERRY 4 SW, 1896–2008
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	28.3°C21 Jan 1906	-33.9°C13 Jan 1912	95 mm22 Jan 1927	255 mm2005 · driest 27 mm in 1946	103
February	26.1°C24 Feb 1906	-29.4°C11 Feb 1899	54 mm14 Feb 1971	193 mm1986 · driest 24 mm in 1941	102
March	30.0°C25 Mar 1929	-23.3°C8 Mar 1986	82 mm17 Mar 1936	231 mm1936 · driest 11 mm in 1910	102
April	33.3°C25 Apr 1915	-15.6°C1 Apr 1923	61 mm2 Apr 1901	214 mm1901 · driest 30 mm in 1932	102
May	37.8°C1 May 1899	-6.1°C7 May 1981	69 mm6 May 1971	259 mm1989 · driest 33 mm in 1926	103
June	36.7°C21 Jun 1953	-2.2°C8 Jun 1977	149 mm23 Jun 1972	388 mm1972 · driest 29 mm in 1967	103
July	40.6°C4 Jul 1911	2.2°C24 Jul 1981	124 mm21 Jul 1916	268 mm1958 · driest 37 mm in 1997	99
August	38.9°C6 Aug 1918	0.0°C29 Aug 1982	105 mm3 Aug 1935	280 mm2003 · driest 25 mm in 1930	100
September	37.8°C3 Sep 1900	-4.4°C14 Sep 1985	140 mm18 Sep 2004	229 mm1926 · driest 19 mm in 1908	100
October	34.4°C16 Oct 1899	-10.0°C28 Oct 1985	127 mm15 Oct 1954	288 mm1954 · driest 4 mm in 1924	102
November	32.2°C21 Nov 1906	-18.3°C29 Nov 1930	56 mm28 Nov 1921	332 mm1985 · driest 8 mm in 1908	104
December	24.4°C4 Dec 1982	-27.2°C30 Dec 1917	53 mm3 Dec 1991	193 mm1990 · driest 15 mm in 1955	104

Typical days per month at DERRY 4 SW, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	20	3	8
February	0	0	18	2	6
March	<1	0	16	4	4
April	3	<1	7	4	<1
May	9	1	1	4	0
June	19	6	0	4	0
July	26	8	0	4	0
August	25	7	0	4	0
September	13	2	<1	3	0
October	4	<1	4	3	<1
November	<1	0	12	4	2
December	0	0	19	3	6

How often, not how much — every day in DERRY 4 SW’s record sorted by what it was actually like, rather than averaged
Month	Warm & dry days	Wet days	Washouts	Week with 3+ wet days	Daytime mean has ranged
January	<1%	42%	10%	60%	-0.2–8.0°C
February	<1%	41%	8%	57%	0.7–8.1°C
March	8%	39%	11%	57%	6.2–14.1°C
April	25%	41%	13%	56%	13.9–19.7°C
May	48%	38%	13%	52%	19.9–25.1°C
June	63%	35%	14%	46%	24.6–28.8°C
July	67%	33%	14%	40%	27.1–31.0°C
August	70%	29%	12%	32%	25.9–30.3°C
September	63%	27%	10%	30%	22.5–27.1°C
October	36%	28%	9%	33%	15.9–21.4°C
November	8%	36%	10%	47%	8.6–14.2°C
December	<1%	39%	9%	55%	1.3–8.8°C

A warm and dry day reaches 20°C with under 1 mm of rain; a wet day gets 1 mm or more; a washout gets 10 mm or more. The week column is the share of seven-day stretches in that month, across the station’s whole daily record, that contained three or more wet days — the odds a week-long trip is rained on repeatedly, counted rather than modelled. The last column is the 10th to 90th percentile of that month’s daytime average across individual years: a narrow band means the average is what you will get, a wide one means the average is a midpoint between years that felt quite different.

1898Each stripe is one year’s mean temperature against the 82-year average. Warmest: 1938. Coolest: 1981.2005

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5186775
NOAA station: USC00362108 · DERRY 4 SW
Station distance: 4.7 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 16 usable years
Daylight: Calculated from latitude 40.33°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Important limit: Historical climate is not a forecast. Nearby stations can miss mountains, coasts, and local microclimates.

These places read the same station, so their numbers are identical — distance from DERRY 4 SW is what differs

Latrobe→Loyalhanna→Blairsville→Lawson Heights→Hostetter→Robinson→

Or put two places side by side: Derry vs Latrobe

Best time to visitDerry.