United States · 1991–2020

Best time to visit
Harwich.

June leads for comfortable weather in Harwich: typically 21.8°C by day, 14.1°C at night, with 77 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortJune

Typical high21.8°C

Typical low14.1°C

Rain in June77 mm

Comfort

June

June · July · August

82climate match

Beach

July

July · August · June

73climate match

Outdoors

June

June · September · May

75climate match

The weakest month is January, scoring 5 against June’s 82 — days reach only 3.8°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

53.8° / -3.5°

Feb

54.5° / -3°

Mar

56.9° / -0.3°

Apr

2311.5° / 4.1°

May

5316.7° / 9.1°

Jun

8221.8° / 14.1°

Jul

8225.8° / 17.9°

Aug

8125.5° / 17.6°

Sep

8122° / 14.3°

Oct

4816.4° / 8.7°

Nov

2311.2° / 3.9°

Dec

56.8° / -0.5°

Monthly climate evidence for Harwich — daylight is calculated from latitude, everything else is measured, sea temperature from the nearest open water 8 km away
Month	Day	Night	Rain	Wet days	Sea	Daylight	Comfort	Coverage
January	3.8°C	-3.5°C	97 mm	10.7	4.7°C	9 h 28	5	Good coverage
February	4.5°C	-3°C	92 mm	9.3	3.3°C	10 h 32	5	Good coverage
March	6.9°C	-0.3°C	110 mm	9.8	3.6°C	11 h 48	5	Good coverage
April	11.5°C	4.1°C	102 mm	9.9	6.2°C	13 h 16	23	Good coverage
May	16.7°C	9.1°C	87 mm	9	10.0°C	14 h 30	53	Good coverage
June	21.8°C	14.1°C	77 mm	7.2	14.8°C	15 h 11	82	Good coverage
July	25.8°C	17.9°C	65 mm	6.1	19.0°C	14 h 55	82	Good coverage
August	25.5°C	17.6°C	79 mm	6.5	20.1°C	13 h 51	81	Good coverage
September	22°C	14.3°C	89 mm	6.6	18.4°C	12 h 25	81	Good coverage
October	16.4°C	8.7°C	109 mm	9.2	14.7°C	11 h 01	48	Good coverage
November	11.2°C	3.9°C	109 mm	8.6	10.4°C	9 h 46	23	Good coverage
December	6.8°C	-0.5°C	112 mm	10.4	7.2°C	9 h 10	5	Good coverage

Records at CHATHAM MUNI AP, 1996–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	15.0°C4 Jan 1998	-20.6°C16 Jan 2004	57 mm20 Jan 2019	230 mm2023 · driest 26 mm in 2025	30
February	17.2°C10 Feb 2023	-19.9°C14 Feb 2016	67 mm5 Feb 2016	191 mm2018 · driest 0 mm in 2025	30
March	18.9°C21 Mar 2012	-13.2°C1 Mar 2015	78 mm30 Mar 2003	225 mm2001 · driest 0 mm in 2025	30
April	29.4°C17 Apr 2002	-4.9°C5 Apr 2016	67 mm1 Apr 2017	170 mm2020 · driest 0 mm in 2025	30
May	32.2°C25 May 2007	-0.6°C7 May 2001	50 mm24 May 1999	176 mm2006 · driest 0 mm in 2025	30
June	33.9°C21 Jun 2012	5.0°C2 Jun 2026	87 mm7 Jun 2006	241 mm2006 · driest 0 mm in 2025	30
July	37.2°C5 Jul 1999	10.0°C21 Jul 2000	59 mm4 Jul 2014	156 mm2009 · driest 0 mm in 2025	31
August	36.7°C2 Aug 2006	9.4°C25 Aug 2004	109 mm19 Aug 2017	191 mm2017 · driest 0 mm in 2025	30
September	32.2°C7 Sep 2023	2.8°C20 Sep 2019	135 mm9 Sep 2021	273 mm2021 · driest 19 mm in 2001	30
October	28.3°C9 Oct 2011	-2.2°C23 Oct 1997	85 mm26 Oct 2022	242 mm2022 · driest 25 mm in 2013	30
November	22.8°C7 Nov 2024	-8.9°C25 Nov 2000	80 mm3 Nov 2007	215 mm2014 · driest 25 mm in 2001	30
December	18.3°C5 Dec 2001	-13.8°C29 Dec 2017	70 mm5 Dec 2020	224 mm2019 · driest 39 mm in 1998	30

Typical days per month at CHATHAM MUNI AP, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)
January	0	0	23	3
February	0	0	22	3
March	0	0	17	4
April	<1	0	4	3
May	<1	<1	<1	3
June	7	<1	0	3
July	20	3	0	2
August	18	2	0	2
September	6	<1	0	3
October	<1	0	<1	3
November	0	0	8	4
December	0	0	18	4

How often, not how much — every day in CHATHAM MUNI 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	0%	34%	11%	41%	2.2–6.2°C
February	0%	31%	11%	40%	1.7–6.5°C
March	0%	32%	12%	43%	5.6–9.0°C
April	2%	31%	10%	40%	10.6–13.6°C
May	21%	28%	8%	31%	15.6–18.3°C
June	62%	23%	9%	24%	20.4–23.6°C
July	79%	20%	6%	18%	23.7–27.7°C
August	79%	21%	7%	19%	23.9–27.1°C
September	61%	22%	10%	22%	21.1–23.3°C
October	16%	29%	12%	35%	15.1–18.5°C
November	1%	29%	11%	34%	10.0–13.3°C
December	0%	33%	12%	48%	4.8–8.9°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.

1997Each stripe is one year’s mean temperature against the 29-year average. Warmest: 2023. Coolest: 2003.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4939004
NOAA station: USW00094624 · CHATHAM MUNI AP
Station distance: 6.9 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 22 usable years
Daylight: Calculated from latitude 41.69°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Sea temperature: NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 8 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 CHATHAM MUNI AP is what differs

Eastham→East Harwich→Northwest Harwich→Dennis Port→Wellfleet→Truro→

Or put two places side by side: Harwich vs Eastham

Best time to visitHarwich.

June

July

June

The whole year,without the guesswork.

Nearby, measured,and named.

Best time to visit
Harwich.

The whole year,
without the guesswork.

Nearby, measured,
and named.