United States · 1991–2020

Best time to visit
Arcanum.

September leads for comfortable weather in Arcanum: typically 25°C by day, 11.4°C at night, with 70 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high25°C

Typical low11.4°C

Rain in September70 mm

Comfort

September

September · August · June

82climate match

Beach

July

July · August · June

71climate match

Outdoors

October

October · September · May

74climate match

The weakest month is January, scoring 5 against September’s 82 — days reach only 0.9°C, 23° 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

50.9° / -7.9°

Feb

53.3° / -6.4°

Mar

99.2° / -1.5°

Apr

3916.6° / 4.1°

May

6922.3° / 10.4°

Jun

7227° / 15.6°

Jul

6728.6° / 17°

Aug

7527.9° / 15.6°

Sep

8225° / 11.4°

Oct

5418.1° / 5.3°

Nov

1710.3° / -0.1°

Dec

53.8° / -4.6°

Monthly climate evidence for Arcanum — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	0.9°C	-7.9°C	72 mm	8.2	9 h 37	5	Strong coverage
February	3.3°C	-6.4°C	57 mm	7.2	10 h 37	5	Strong coverage
March	9.2°C	-1.5°C	82 mm	9.5	11 h 49	9	Strong coverage
April	16.6°C	4.1°C	106 mm	10.9	13 h 12	39	Strong coverage
May	22.3°C	10.4°C	110 mm	10.8	14 h 22	69	Strong coverage
June	27°C	15.6°C	112 mm	10.5	15 h	72	Strong coverage
July	28.6°C	17°C	100 mm	8.2	14 h 45	67	Strong coverage
August	27.9°C	15.6°C	86 mm	6.8	13 h 45	75	Strong coverage
September	25°C	11.4°C	70 mm	7.1	12 h 24	82	Strong coverage
October	18.1°C	5.3°C	74 mm	7.4	11 h 04	54	Strong coverage
November	10.3°C	-0.1°C	79 mm	7.6	9 h 55	17	Strong coverage
December	3.8°C	-4.6°C	74 mm	8.4	9 h 21	5	Strong coverage

What has changed

Arcanum runs +1.1°C
on the 1961–1990 baseline.

Each bar compares the 2011–2025 daytime average for that month against the same month in 1961–1990, measured at the same station. Months where the older record is too thin to compare are left blank.

Jan

+1.5

Feb

+2.6

Mar

+2.1

Apr

+1.1

May

+1.1

Jun

+0.7

Jul

+0.2

Aug

-0.1

Sep

+0.8

Oct

+0.9

Nov

+0.3

Dec

+2.4

September daytime highs, 2011–2025. Last recorded: 27.0°C.

Records at GREENVILLE WTP, 1893–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	21.7°C25 Jan 1950	-36.1°C19 Jan 1994	81 mm15 Jan 1937	275 mm1937 · driest 7 mm in 1981	131
February	23.9°C20 Feb 2018	-30.6°C3 Feb 1985	63 mm25 Feb 1956	161 mm1909 · driest 5 mm in 1968	133
March	29.4°C23 Mar 2026	-25.6°C9 Mar 1984	113 mm25 Mar 1913	292 mm1913 · driest 1 mm in 1910	132
April	32.2°C30 Apr 1942	-12.2°C6 Apr 1982	84 mm22 Apr 1925	232 mm2011 · driest 23 mm in 1971	133
May	36.7°C27 May 1911	-5.0°C10 May 1966	88 mm13 May 1933	305 mm1933 · driest 16 mm in 1934	133
June	38.3°C26 Jun 1988	2.2°C5 Jun 1945	115 mm8 Jun 1924	320 mm1958 · driest 14 mm in 1983	133
July	40.6°C21 Jul 1934	6.1°C1 Jul 1943	108 mm14 Jul 2015	255 mm1987 · driest 7 mm in 1916	133
August	38.3°C18 Aug 1988	2.2°C29 Aug 1986	132 mm10 Aug 1969	196 mm1926 · driest 9 mm in 1938	132
September	37.8°C2 Sep 1953	-3.3°C28 Sep 1942	116 mm21 Sep 1950	237 mm1925 · driest 1 mm in 1963	133
October	32.2°C8 Oct 2007	-10.0°C21 Oct 1952	74 mm6 Oct 1995	198 mm1919 · driest 1 mm in 1924	133
November	26.7°C2 Nov 2016	-18.9°C30 Nov 1929	62 mm14 Nov 1993	213 mm1985 · driest 3 mm in 1904	132
December	22.2°C3 Dec 1982	-29.4°C22 Dec 1989	71 mm1 Dec 2006	210 mm1990 · driest 6 mm in 1955	132

Typical days per month at GREENVILLE WTP, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	27	2	4
February	0	0	24	2	3
March	<1	0	20	3	2
April	3	0	7	4	<1
May	11	2	<1	4	0
June	22	8	0	4	0
July	28	11	0	3	0
August	26	9	0	3	0
September	16	5	<1	2	0
October	5	<1	5	3	0
November	<1	0	17	3	<1
December	0	0	25	2	3

How often, not how much — every day in GREENVILLE WTP’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%	26%	7%	27%	-2.2–5.2°C
February	<1%	24%	7%	24%	-0.9–6.8°C
March	6%	30%	10%	34%	5.3–13.3°C
April	23%	34%	11%	45%	13.5–18.7°C
May	47%	34%	11%	43%	19.3–25.4°C
June	66%	31%	12%	35%	24.8–29.1°C
July	73%	27%	11%	27%	27.0–31.1°C
August	76%	23%	9%	22%	26.3–29.8°C
September	67%	23%	9%	21%	22.7–26.8°C
October	33%	23%	8%	24%	15.5–20.6°C
November	6%	26%	8%	25%	7.2–13.1°C
December	<1%	27%	7%	28%	0.0–6.6°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.

1894Each stripe is one year’s mean temperature against the 127-year average. Warmest: 1921. Coolest: 1978.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4505390
NOAA station: USC00333375 · GREENVILLE WTP
Station distance: 15.1 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 29 usable years
Daylight: Calculated from latitude 39.99°, 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 GREENVILLE WTP is what differs

Greenville→Versailles→Ansonia→New Madison→Wayne Lakes Park→Gettysburg→

Or put two places side by side: Arcanum vs Greenville

Best time to visitArcanum.