United States · 1991–2020

Best time to visit
Unionville.

August leads for comfortable weather in Unionville: typically 27°C by day, 14.4°C at night, with 81 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortAugust

Typical high27°C

Typical low14.4°C

Rain in August81 mm

Comfort

August

August · June · September

78climate match

Beach

July

July · August · June

67climate match

Outdoors

September

September · May · June

77climate match

The weakest month is January, scoring 5 against August’s 78 — days reach only -1.1°C, 25° 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

5-1.1° / -9.4°

Feb

50° / -9.6°

Mar

55.9° / -4.6°

Apr

2713.5° / 1°

May

6020.4° / 7.1°

Jun

7725.9° / 12.5°

Jul

7428° / 15.4°

Aug

7827° / 14.4°

Sep

7722.9° / 10.1°

Oct

4215.8° / 4.7°

Nov

97.9° / -0.7°

Dec

51.5° / -5.6°

Monthly climate evidence for Unionville — daylight is calculated from latitude, everything else is measured, sea temperature from the nearest open water 28 km away
Month	Day	Night	Rain	Wet days	Sea	Daylight	Comfort	Coverage
January	-1.1°C	-9.4°C	55 mm	9.4	1.6°C	9 h 16	5	Strong coverage
February	0°C	-9.6°C	41 mm	6.8	0.6°C	10 h 25	5	Strong coverage
March	5.9°C	-4.6°C	51 mm	7	1.0°C	11 h 47	5	Strong coverage
April	13.5°C	1°C	90 mm	9.6	3.8°C	13 h 22	27	Strong coverage
May	20.4°C	7.1°C	89 mm	10.3	8.3°C	14 h 41	60	Strong coverage
June	25.9°C	12.5°C	87 mm	8.8	15.3°C	15 h 25	77	Strong coverage
July	28°C	15.4°C	85 mm	8.6	20.6°C	15 h 08	74	Good coverage
August	27°C	14.4°C	81 mm	8.4	21.8°C	13 h 59	78	Strong coverage
September	22.9°C	10.1°C	81 mm	8.1	19.2°C	12 h 27	77	Strong coverage
October	15.8°C	4.7°C	81 mm	9.8	13.1°C	10 h 56	42	Strong coverage
November	7.9°C	-0.7°C	65 mm	8.9	7.8°C	9 h 36	9	Strong coverage
December	1.5°C	-5.6°C	53 mm	9	4.0°C	8 h 57	5	Strong coverage

What has changed

Unionville runs -0.3°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

+0.5

Feb

+0.1

Mar

-0.4

Apr

-1.7

May

-1.0

Jun

-0.6

Jul

-0.7

Aug

-0.5

Sep

+0.3

Oct

-0.2

Nov

-0.3

Dec

+1.3

August daytime highs, 2011–2025. Last recorded: 27.3°C.

Records at CARO WWTP, 1928–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	22.8°C6 Jan 1939	-31.7°C18 Jan 1976	38 mm31 Jan 1946	116 mm2008 · driest 4 mm in 1945	95
February	22.2°C28 Feb 2024	-34.4°C9 Feb 1934	50 mm21 Feb 1997	125 mm1997 · driest 3 mm in 1969	97
March	30.6°C22 Mar 2012	-28.9°C5 Mar 1948	71 mm11 Mar 2026	202 mm1976 · driest 7 mm in 1958	97
April	32.2°C26 Apr 1948	-14.4°C3 Apr 1965	70 mm5 Apr 1929	205 mm1929 · driest 9 mm in 1946	98
May	34.4°C30 May 1987	-5.6°C5 May 1967	72 mm20 May 1996	167 mm1996 · driest 10 mm in 1977	97
June	38.9°C1 Jun 1934	-2.2°C8 Jun 1949	102 mm24 Jun 1994	207 mm1994 · driest 19 mm in 2007	92
July	42.2°C13 Jul 1936	1.1°C20 Jul 1965	70 mm10 Jul 1970	179 mm2023 · driest 15 mm in 1989	93
August	38.3°C8 Aug 2001	0.0°C29 Aug 1982	84 mm3 Aug 2015	196 mm2023 · driest 11 mm in 1930	93
September	38.9°C1 Sep 1953	-6.1°C29 Sep 1942	185 mm11 Sep 1986	461 mm1986 · driest 14 mm in 1969	94
October	31.7°C9 Oct 2007	-11.1°C28 Oct 1976	81 mm3 Oct 1954	208 mm1954 · driest 7 mm in 1952	95
November	26.7°C1 Nov 1950	-18.9°C30 Nov 1958	59 mm11 Nov 1995	136 mm1995 · driest 8 mm in 1938	96
December	20.6°C6 Dec 2001	-27.8°C25 Dec 2000	66 mm1 Dec 2009	136 mm1972 · driest 7 mm in 1958	96

Typical days per month at CARO WWTP, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	29	2	8
February	0	0	26	1	6
March	<1	0	25	2	3
April	1	<1	15	3	<1
May	7	2	2	3	0
June	19	6	0	3	0
July	25	9	0	3	0
August	22	6	0	3	0
September	11	2	<1	3	0
October	2	<1	6	3	0
November	0	0	18	2	2
December	0	0	27	1	6

The best month has moved. On the 1961–1990 numbers the strongest month here was June (scoring 79); on 2011–2025 it is September (84). Both are scored the same way, from the same station — only the climate underneath changed.

How often, not how much — every day in CARO WWTP’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	0%	26%	4%	26%	-3.8–3.0°C
February	0%	23%	3%	20%	-2.5–3.3°C
March	4%	24%	5%	26%	3.2–9.8°C
April	15%	31%	7%	38%	11.3–16.8°C
May	43%	30%	8%	35%	18.2–24.3°C
June	67%	29%	10%	33%	24.2–28.5°C
July	75%	25%	8%	25%	27.2–30.7°C
August	73%	26%	9%	26%	25.7–29.9°C
September	57%	28%	9%	32%	21.9–25.3°C
October	25%	28%	8%	32%	14.1–19.2°C
November	3%	29%	6%	33%	5.3–11.1°C
December	0%	28%	4%	29%	-1.6–4.5°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.

1928Each stripe is one year’s mean temperature against the 82-year average. Warmest: 2024. Coolest: 2014.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5012957
NOAA station: USC00201299 · CARO WWTP
Station distance: 19.8 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 24 usable years
Daylight: Calculated from latitude 43.65°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Sea temperature: NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 28 km from the place centre. A sheltered bay can run warmer than the open sea it is measured from.
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 CARO WWTP is what differs

Caro→Mayville→Fairgrove→Kingston→Akron→Clifford→

Or put two places side by side: Unionville vs Caro

Best time to visitUnionville.