United States · 1991–2020

Best time to visit
Chatham.

September leads for comfortable weather in Chatham: typically 25.8°C by day, 13°C at night, with 118 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high25.8°C

Typical low13°C

Rain in September118 mm

Comfort

September

September · May · June

75climate match

Beach

August

August · July · June

68climate match

Outdoors

May

May · October · April

71climate match

The weakest month is January, scoring 5 against September’s 75 — days reach only 4.5°C, 19° 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

54.5° / -6°

Feb

55.8° / -5.3°

Mar

1210.2° / -1.1°

Apr

4517.2° / 4.4°

May

7022.7° / 9.8°

Jun

6927.8° / 15.2°

Jul

5630.5° / 18.2°

Aug

6229.6° / 17.2°

Sep

7525.8° / 13°

Oct

5319° / 6.3°

Nov

2512.5° / 1°

Dec

57.2° / -2.8°

Monthly climate evidence for Chatham — daylight is calculated from latitude, everything else is measured, sea temperature from the nearest open water 45 km away
Month	Day	Night	Rain	Wet days	Sea	Daylight	Comfort	Coverage
January	4.5°C	-6°C	85 mm	7.9	6.0°C	9 h 33	5	Strong coverage
February	5.8°C	-5.3°C	74 mm	6.7	4.3°C	10 h 35	5	Strong coverage
March	10.2°C	-1.1°C	103 mm	7.9	4.8°C	11 h 49	12	Strong coverage
April	17.2°C	4.4°C	97 mm	8.5	7.9°C	13 h 14	45	Strong coverage
May	22.7°C	9.8°C	103 mm	10.1	12.6°C	14 h 26	70	Strong coverage
June	27.8°C	15.2°C	121 mm	9.4	18.1°C	15 h 05	69	Strong coverage
July	30.5°C	18.2°C	119 mm	9.2	22.2°C	14 h 49	56	Strong coverage
August	29.6°C	17.2°C	111 mm	8.6	23.1°C	13 h 47	62	Strong coverage
September	25.8°C	13°C	118 mm	7.5	21.4°C	12 h 25	75	Strong coverage
October	19°C	6.3°C	114 mm	7.8	17.3°C	11 h 03	53	Strong coverage
November	12.5°C	1°C	92 mm	7.3	12.7°C	9 h 51	25	Strong coverage
December	7.2°C	-2.8°C	112 mm	8.4	9.0°C	9 h 16	5	Strong coverage

What has changed

Chatham runs +1.4°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

+1.9

Feb

+1.9

Mar

+1.1

Apr

+1.6

May

+1.1

Jun

+1.3

Jul

+1.9

Aug

+1.3

Sep

+1.5

Oct

+0.8

Nov

+0.1

Dec

+1.9

September daytime highs, 2011–2025. Last recorded: 26.7°C.

Records at CANOE BROOK, 1931–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	22.8°C27 Jan 1950	-31.7°C28 Jan 1935	82 mm10 Jan 2024	267 mm1979 · driest 0 mm in 2026	96
February	26.1°C22 Feb 2018	-32.2°C9 Feb 1934	71 mm25 Feb 2016	169 mm2008 · driest 12 mm in 2002	94
March	31.7°C31 Mar 1998	-21.1°C1 Mar 1934	104 mm14 Mar 2010	304 mm2010 · driest 16 mm in 2006	95
April	35.6°C18 Apr 2002	-11.1°C4 Apr 1954	136 mm16 Apr 2007	311 mm2007 · driest 1 mm in 2023	95
May	36.1°C20 May 1962	-3.9°C10 May 1986	113 mm29 May 1968	282 mm1968 · driest 4 mm in 2023	95
June	39.4°C10 Jun 2011	-0.6°C8 Jun 1932	146 mm6 Jun 1992	285 mm1972 · driest 1 mm in 1949	94
July	41.7°C7 Jul 2010	5.0°C15 Jul 1940	129 mm25 Jul 1997	348 mm1945 · driest 11 mm in 1955	95
August	40.0°C10 Aug 2001	1.7°C30 Aug 1934	223 mm28 Aug 1971	372 mm1942 · driest 5 mm in 1964	92
September	37.8°C9 Sep 2015	-3.3°C27 Sep 1947	193 mm17 Sep 1999	324 mm1999 · driest 4 mm in 2024	94
October	34.4°C3 Oct 2019	-10.6°C28 Oct 1936	121 mm30 Oct 1973	355 mm2005 · driest 0 mm in 2024	95
November	28.9°C3 Nov 1950	-20.6°C26 Nov 1938	134 mm9 Nov 1972	289 mm1932 · driest 4 mm in 2021	92
December	24.4°C5 Dec 1998	-26.7°C28 Dec 1933	77 mm31 Dec 1948	276 mm1983 · driest 4 mm in 1955	94

Typical days per month at CANOE BROOK, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	26	3	3
February	0	0	24	3	3
March	<1	0	19	3	2
April	4	<1	6	3	<1
May	11	4	<1	4	0
June	22	11	0	4	0
July	29	18	0	4	0
August	28	16	0	4	0
September	18	5	0	4	0
October	4	<1	3	4	0
November	<1	0	14	3	<1
December	0	0	23	4	1

How often, not how much — every day in CANOE BROOK’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%	25%	10%	27%	0.5–7.3°C
February	<1%	25%	9%	25%	2.4–8.2°C
March	6%	28%	11%	32%	7.0–12.8°C
April	23%	30%	11%	36%	14.2–18.8°C
May	51%	32%	12%	42%	20.1–24.6°C
June	68%	30%	11%	36%	25.3–29.3°C
July	71%	29%	12%	34%	28.5–32.0°C
August	72%	28%	12%	29%	27.2–30.7°C
September	69%	25%	11%	25%	23.4–27.1°C
October	37%	23%	10%	23%	17.1–21.5°C
November	7%	25%	11%	25%	10.1–15.0°C
December	<1%	26%	11%	27%	3.2–8.9°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.

1931Each stripe is one year’s mean temperature against the 82-year average. Warmest: 2024. Coolest: 1940.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5096495
NOAA station: USC00281335 · CANOE BROOK
Station distance: 2.5 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 27 usable years
Daylight: Calculated from latitude 40.74°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Sea temperature: NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 45 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 CANOE BROOK is what differs

Maplewood→Summit→Millburn→Morristown→South Orange→Madison→

Or put two places side by side: Chatham vs Maplewood

Best time to visitChatham.

September

August

May

The whole year,without the guesswork.

Chatham runs +1.4°Con the 1961–1990 baseline.

Nearby, measured,and named.

Best time to visit
Chatham.

The whole year,
without the guesswork.

Chatham runs +1.4°C
on the 1961–1990 baseline.

Nearby, measured,
and named.