United States · 1991–2020

Best time to visit
Aix.

September leads for comfortable weather in Aix: typically 25.1°C by day, 12°C at night, with 90 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high25.1°C

Typical low12°C

Rain in September90 mm

Comfort

September

September · August · May

79climate match

Beach

July

July · August · June

70climate match

Outdoors

October

October · May · September

69climate match

The weakest month is January, scoring 5 against September’s 79 — days reach only 0°C, 24° 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° / -8.5°

Feb

52.5° / -6.7°

Mar

88.8° / -1.5°

Apr

3516.2° / 4.1°

May

6822.4° / 10.6°

Jun

6527.5° / 16°

Jul

6228.9° / 17.6°

Aug

7028° / 16.5°

Sep

7925.1° / 12°

Oct

5017.8° / 5.5°

Nov

149.5° / -0.1°

Dec

52.8° / -5.3°

Monthly climate evidence for Aix — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	0°C	-8.5°C	70 mm	9.1	9 h 31	5	Strong coverage
February	2.5°C	-6.7°C	55 mm	7	10 h 34	5	Strong coverage
March	8.8°C	-1.5°C	81 mm	9.4	11 h 49	8	Strong coverage
April	16.2°C	4.1°C	117 mm	11.8	13 h 15	35	Strong coverage
May	22.4°C	10.6°C	120 mm	11	14 h 27	68	Strong coverage
June	27.5°C	16°C	143 mm	10.1	15 h 07	65	Strong coverage
July	28.9°C	17.6°C	118 mm	8.7	14 h 51	62	Strong coverage
August	28°C	16.5°C	103 mm	8.1	13 h 49	70	Strong coverage
September	25.1°C	12°C	90 mm	7.4	12 h 25	79	Strong coverage
October	17.8°C	5.5°C	89 mm	8.9	11 h 02	50	Strong coverage
November	9.5°C	-0.1°C	74 mm	8.8	9 h 50	14	Strong coverage
December	2.8°C	-5.3°C	66 mm	8.7	9 h 14	5	Strong coverage

What has changed

Aix runs +0.8°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

+0.8

Mar

+1.4

Apr

+0.6

May

+0.4

Jun

+0.5

Jul

-0.2

Aug

+0.2

Sep

+1.5

Oct

+1.5

Nov

+0.2

Dec

+2.5

September daytime highs, 2011–2025. Last recorded: 26.3°C.

Records at RENSSELAER WWTP, 1970–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	18.9°C8 Jan 2008	-31.7°C20 Jan 1985	90 mm8 Jan 2008	155 mm2008 · driest 0 mm in 1971	54
February	22.2°C11 Feb 1999	-30.0°C10 Feb 1982	71 mm21 Feb 2018	170 mm2018 · driest 0 mm in 1987	54
March	30.6°C22 Mar 2012	-20.6°C5 Mar 1978	66 mm8 Mar 1998	170 mm1998 · driest 9 mm in 1971	54
April	32.2°C26 Apr 1986	-16.7°C7 Apr 1982	57 mm25 Apr 2007	234 mm2011 · driest 17 mm in 2004	55
May	36.7°C29 May 2018	-4.4°C9 May 2020	121 mm19 May 1987	222 mm1986 · driest 20 mm in 2005	54
June	39.4°C26 Jun 1988	2.8°C1 Jun 2003	98 mm23 Jun 2018	327 mm2015 · driest 8 mm in 1991	55
July	38.3°C16 Jul 1988	5.6°C31 Jul 1971	122 mm6 Jul 1994	430 mm2003 · driest 18 mm in 1974	56
August	40.0°C18 Aug 1988	5.0°C29 Aug 1986	97 mm22 Aug 2014	236 mm2016 · driest 17 mm in 1984	55
September	36.1°C11 Sep 2013	-1.1°C22 Sep 1995	117 mm28 Sep 2019	238 mm1993 · driest 0 mm in 1979	55
October	32.2°C1 Oct 1971	-6.1°C22 Oct 1976	91 mm16 Oct 1993	231 mm2001 · driest 19 mm in 2024	54
November	26.1°C9 Nov 2020	-16.7°C13 Nov 2019	89 mm2 Nov 1982	204 mm1985 · driest 15 mm in 1980	56
December	22.2°C4 Dec 2012	-30.6°C22 Dec 1989	60 mm15 Dec 2011	169 mm1990 · driest 15 mm in 1995	56

Typical days per month at RENSSELAER WWTP, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	28	2	6
February	0	0	25	2	5
March	<1	0	20	2	3
April	3	<1	6	4	<1
May	12	4	<1	4	0
June	23	10	0	4	0
July	28	12	0	4	0
August	27	9	0	3	0
September	17	5	<1	3	0
October	5	<1	4	3	0
November	<1	0	17	3	<1
December	0	0	26	2	4

How often, not how much — every day in RENSSELAER 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%	6%	26%	-3.4–2.9°C
February	<1%	25%	6%	25%	-1.8–5.8°C
March	6%	29%	9%	35%	5.5–12.8°C
April	20%	34%	12%	41%	13.6–18.7°C
May	47%	33%	12%	37%	19.7–25.6°C
June	65%	31%	14%	34%	25.6–29.0°C
July	72%	28%	12%	28%	27.5–30.9°C
August	73%	26%	10%	23%	26.7–29.8°C
September	64%	26%	9%	26%	22.7–27.0°C
October	28%	28%	9%	29%	15.1–20.3°C
November	5%	27%	9%	29%	6.1–12.6°C
December	0%	28%	7%	32%	-1.4–6.2°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.

1972Each stripe is one year’s mean temperature against the 47-year average. Warmest: 1998. Coolest: 1982.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4917515
NOAA station: USC00127298 · RENSSELAER WWTP
Station distance: 13.2 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 25 usable years
Daylight: Calculated from latitude 41.04°, 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 RENSSELAER WWTP is what differs

Rensselaer→Remington→Collegeville→Mount Ayr→Egypt→Enos→

Or put two places side by side: Aix vs Rensselaer

Best time to visitAix.