United States · 1991–2020

Best time to visit
New Boston.

September leads for comfortable weather in New Boston: typically 25.6°C by day, 12.8°C at night, with 84 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high25.6°C

Typical low12.8°C

Rain in September84 mm

Comfort

September

September · May · June

81climate match

Beach

July

July · August · June

77climate match

Outdoors

October

October · April · September

77climate match

The weakest month is January, scoring 5 against September’s 81 — days reach only -0.1°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

5-0.1° / -8.9°

Feb

52.2° / -7.3°

Mar

149.2° / -1.1°

Apr

4616.9° / 5°

May

7022.8° / 11.1°

Jun

6828° / 16.6°

Jul

6330.1° / 18.7°

Aug

6828.9° / 17.1°

Sep

8125.6° / 12.8°

Oct

5617.9° / 6.4°

Nov

2310.2° / 0.4°

Dec

52.7° / -5.7°

Monthly climate evidence for New Boston — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	-0.1°C	-8.9°C	35 mm	5.3	9 h 31	5	Good coverage
February	2.2°C	-7.3°C	38 mm	4.7	10 h 33	5	Good coverage
March	9.2°C	-1.1°C	67 mm	6.7	11 h 48	14	Good coverage
April	16.9°C	5°C	87 mm	8.4	13 h 15	46	Good coverage
May	22.8°C	11.1°C	128 mm	9.9	14 h 28	70	Good coverage
June	28°C	16.6°C	116 mm	8.5	15 h 07	68	Good coverage
July	30.1°C	18.7°C	87 mm	6.4	14 h 52	63	Good coverage
August	28.9°C	17.1°C	97 mm	7.2	13 h 49	68	Good coverage
September	25.6°C	12.8°C	84 mm	5.8	12 h 25	81	Good coverage
October	17.9°C	6.4°C	73 mm	6.1	11 h 02	56	Good coverage
November	10.2°C	0.4°C	54 mm	5.8	9 h 49	23	Good coverage
December	2.7°C	-5.7°C	44 mm	5.8	9 h 13	5	Good coverage

Records at NEW BOSTON DAM 17, 1938–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	17.8°C9 Jan 2003	-32.2°C31 Jan 2019	41 mm18 Jan 2020	73 mm2020 · driest 5 mm in 2003	39
February	23.9°C28 Feb 2024	-31.7°C1 Feb 2019	47 mm9 Feb 2001	108 mm2001 · driest 2 mm in 2024	39
March	30.0°C22 Mar 2026	-25.6°C1 Mar 2015	115 mm13 Mar 2006	190 mm2006 · driest 4 mm in 2015	41
April	31.1°C18 Apr 2002	-8.3°C8 Apr 2018	85 mm24 Apr 1976	200 mm2024 · driest 20 mm in 1946	40
May	43.9°C24 May 1939	-2.2°C3 May 2005	128 mm1 May 2003	288 mm2019 · driest 33 mm in 1940	41
June	37.2°C24 Jun 1938	-0.6°C2 Jun 2001	107 mm22 Jun 2007	240 mm1946 · driest 44 mm in 2004	40
July	40.6°C28 Jul 2011	9.4°C23 Jul 1947	81 mm12 Jul 2025	325 mm2025 · driest 14 mm in 1997	40
August	39.4°C25 Aug 2023	7.8°C24 Aug 1942	190 mm17 Aug 1939	304 mm1939 · driest 0 mm in 2013	40
September	37.2°C2 Sep 2011	-1.1°C28 Sep 1942	108 mm21 Sep 1947	271 mm2008 · driest 0 mm in 1979	39
October	33.3°C18 Oct 2016	-6.1°C26 Oct 1942	59 mm18 Oct 1998	180 mm1941 · driest 10 mm in 1999	37
November	27.8°C2 Nov 2016	-14.4°C30 Nov 1947	50 mm5 Nov 2022	114 mm2015 · driest 2 mm in 1999	39
December	22.8°C16 Dec 2021	-27.8°C26 Dec 2000	91 mm27 Dec 1942	116 mm1942 · driest 9 mm in 1943	39

Typical days per month at NEW BOSTON DAM 17, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	28	1	<1
February	0	0	24	1	<1
March	<1	0	19	3	0
April	3	<1	5	3	0
May	12	3	<1	4	0
June	24	11	0	4	0
July	29	17	0	3	0
August	27	12	0	3	0
September	18	6	0	3	0
October	5	<1	3	3	0
November	<1	0	14	2	0
December	0	0	25	2	<1

How often, not how much — every day in NEW BOSTON DAM 17’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%	18%	4%	13%	-3.2–3.3°C
February	<1%	17%	3%	13%	-2.3–6.2°C
March	8%	24%	7%	25%	5.5–14.1°C
April	25%	29%	10%	35%	14.8–19.7°C
May	51%	30%	12%	36%	19.6–25.5°C
June	67%	28%	12%	31%	26.2–29.9°C
July	79%	24%	10%	24%	28.5–32.7°C
August	76%	23%	10%	23%	27.1–30.7°C
September	74%	21%	9%	20%	23.3–27.9°C
October	38%	19%	8%	21%	16.0–21.1°C
November	7%	19%	6%	15%	6.7–12.7°C
December	<1%	19%	4%	16%	-1.0–6.4°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.

1940Each stripe is one year’s mean temperature against the 33-year average. Warmest: 2024. Coolest: 2014.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4903454
NOAA station: USC00116080 · NEW BOSTON DAM 17
Station distance: 5.6 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 23 usable years
Daylight: Calculated from latitude 41.17°, 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 NEW BOSTON DAM 17 is what differs

Wapello→Morning Sun→Keithsburg→Oakville→Elrick Junction→Garland→

Or put two places side by side: New Boston vs Wapello

Best time to visitNew Boston.