United States · 1991–2020

Best time to visit
Greencastle.

September leads for comfortable weather in Greencastle: typically 25.3°C by day, 14.7°C at night, with 96 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high25.3°C

Typical low14.7°C

Rain in September96 mm

Comfort

September

September · May · June

82climate match

Beach

August

August · July · June

82climate match

Outdoors

October

October · April · May

81climate match

The weakest month is January, scoring 5 against September’s 82 — days reach only 4.1°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

54.1° / -4.2°

Feb

56° / -3.1°

Mar

2311.4° / 0.9°

Apr

5218° / 6.5°

May

7823.3° / 12.3°

Jun

7027.9° / 17.2°

Jul

6030.3° / 19.5°

Aug

6729.2° / 18.6°

Sep

8225.3° / 14.7°

Oct

6118.6° / 8.4°

Nov

3412.5° / 2.8°

Dec

56.4° / -1.6°

Monthly climate evidence for Greencastle — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	4.1°C	-4.2°C	66 mm	8	9 h 38	5	Good coverage
February	6°C	-3.1°C	60 mm	7	10 h 38	5	Good coverage
March	11.4°C	0.9°C	73 mm	8	11 h 49	23	Good coverage
April	18°C	6.5°C	86 mm	9	13 h 12	52	Good coverage
May	23.3°C	12.3°C	95 mm	10.5	14 h 21	78	Good coverage
June	27.9°C	17.2°C	91 mm	8.9	14 h 58	70	Good coverage
July	30.3°C	19.5°C	81 mm	8.6	14 h 44	60	Good coverage
August	29.2°C	18.6°C	71 mm	7.5	13 h 44	67	Good coverage
September	25.3°C	14.7°C	96 mm	7.7	12 h 24	82	Good coverage
October	18.6°C	8.4°C	77 mm	7	11 h 05	61	Good coverage
November	12.5°C	2.8°C	57 mm	6.1	9 h 56	34	Good coverage
December	6.4°C	-1.6°C	76 mm	7.3	9 h 22	5	Good coverage

Records at HAGERSTOWN RGNL AP, 1998–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	21.7°C26 Jan 2024	-18.8°C7 Jan 2014	46 mm25 Jan 2010	139 mm1999 · driest 8 mm in 2025	28
February	27.8°C21 Feb 2018	-17.1°C20 Feb 2015	54 mm6 Feb 2004	126 mm2003 · driest 5 mm in 2002	28
March	29.4°C22 Mar 2026	-16.6°C6 Mar 2015	54 mm21 Mar 2019	122 mm2011 · driest 11 mm in 2006	28
April	34.4°C6 Apr 2010	-5.5°C4 Apr 2013	52 mm16 Apr 2011	190 mm2011 · driest 44 mm in 2010	28
May	35.6°C30 May 2006	-0.5°C9 May 2020	51 mm13 May 2025	187 mm2025 · driest 22 mm in 2023	28
June	38.9°C29 Jun 2012	7.2°C2 Jun 2003	76 mm26 Jun 2006	230 mm2006 · driest 26 mm in 2010	28
July	38.9°C16 Jul 2024	10.0°C2 Jul 2001	74 mm22 Jul 2024	154 mm2014 · driest 17 mm in 2010	28
August	38.3°C12 Aug 2021	8.9°C21 Aug 2000	58 mm7 Aug 2023	158 mm2018 · driest 17 mm in 2006	27
September	36.1°C3 Sep 2010	2.8°C30 Sep 2000	99 mm1 Sep 2021	237 mm2018 · driest 5 mm in 2005	27
October	33.9°C2 Oct 2019	-3.8°C30 Oct 2011	106 mm7 Oct 2005	169 mm2012 · driest 15 mm in 2024	28
November	28.3°C6 Nov 2024	-8.3°C24 Nov 2000	58 mm21 Nov 2023	148 mm2018 · driest 13 mm in 1998	28
December	23.9°C7 Dec 1998	-16.6°C24 Dec 2022	54 mm24 Dec 2020	133 mm2009 · driest 14 mm in 1998	28

Typical days per month at HAGERSTOWN RGNL AP, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)
January	0	0	24	2
February	<1	0	22	2
March	<1	0	15	2
April	4	<1	3	3
May	13	4	0	3
June	25	10	0	3
July	30	18	0	3
August	28	14	0	3
September	17	5	0	3
October	4	<1	<1	2
November	<1	0	9	2
December	0	0	21	3

How often, not how much — every day in HAGERSTOWN RGNL AP’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%	24%	7%	29%	1.0–7.8°C
February	2%	25%	7%	25%	2.6–9.8°C
March	10%	25%	7%	27%	8.2–15.8°C
April	29%	29%	10%	36%	16.2–21.1°C
May	53%	34%	11%	45%	21.1–25.4°C
June	70%	29%	10%	33%	26.9–29.1°C
July	73%	27%	8%	28%	28.6–32.3°C
August	75%	25%	8%	25%	27.6–30.8°C
September	69%	25%	10%	26%	23.4–27.4°C
October	36%	21%	7%	19%	16.8–21.2°C
November	10%	20%	6%	17%	10.0–15.1°C
December	1%	23%	8%	23%	3.3–9.3°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.

1999Each stripe is one year’s mean temperature against the 27-year average. Warmest: 2024. Coolest: 2003.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4558369
NOAA station: USW00093706 · HAGERSTOWN RGNL AP
Station distance: 9.4 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 22 usable years
Daylight: Calculated from latitude 39.79°, 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 HAGERSTOWN RGNL AP is what differs

Fountainhead-Orchard Hills→Maugansville→State Line→Paramount-Long Meadow→Wilson-Conococheague→Mercersburg→

Or put two places side by side: Greencastle vs Fountainhead-Orchard Hills

Best time to visitGreencastle.