United States · 1991–2020

Best time to visit
Delaware.

September leads for comfortable weather in Delaware: typically 25.2°C by day, 12.5°C at night, with 81 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high25.2°C

Typical low12.5°C

Rain in September81 mm

Comfort

September

September · May · August

81climate match

Beach

August

August · July · June

73climate match

Outdoors

October

October · September · May

78climate match

The weakest month is January, scoring 5 against September’s 81 — days reach only 1.9°C, 22° 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

51.9° / -6.2°

Feb

53.8° / -5°

Mar

139.7° / -0.7°

Apr

4417.1° / 4.9°

May

7223.2° / 11.1°

Jun

6827.5° / 15.9°

Jul

6229.3° / 17.9°

Aug

7128.6° / 16.8°

Sep

8125.2° / 12.5°

Oct

5718.3° / 6.5°

Nov

2110.5° / 0.9°

Dec

54.2° / -3.4°

Monthly climate evidence for Delaware — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	1.9°C	-6.2°C	68 mm	8.6	9 h 35	5	Strong coverage
February	3.8°C	-5°C	59 mm	7.7	10 h 36	5	Strong coverage
March	9.7°C	-0.7°C	77 mm	9.1	11 h 49	13	Strong coverage
April	17.1°C	4.9°C	99 mm	10.3	13 h 13	44	Strong coverage
May	23.2°C	11.1°C	115 mm	11.5	14 h 23	72	Strong coverage
June	27.5°C	15.9°C	125 mm	10	15 h 02	68	Strong coverage
July	29.3°C	17.9°C	106 mm	8.9	14 h 47	62	Strong coverage
August	28.6°C	16.8°C	86 mm	7.4	13 h 46	71	Strong coverage
September	25.2°C	12.5°C	81 mm	7.3	12 h 24	81	Strong coverage
October	18.3°C	6.5°C	69 mm	7.2	11 h 04	57	Strong coverage
November	10.5°C	0.9°C	73 mm	7.5	9 h 53	21	Strong coverage
December	4.2°C	-3.4°C	74 mm	8.4	9 h 19	5	Strong coverage

What has changed

Delaware runs +1.2°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

+1.1

Feb

+1.5

Mar

+1.3

Apr

+0.8

May

+1.4

Jun

+0.8

Jul

+0.5

Aug

+0.6

Sep

+1.7

Oct

+1.4

Nov

+0.6

Dec

+2.3

September daytime highs, 2011–2025. Last recorded: 27.8°C.

Records at MARYSVILLE, 1917–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	22.2°C25 Jan 1950	-30.6°C10 Jan 1982	71 mm21 Jan 1959	256 mm1937 · driest 11 mm in 1963	109
February	23.9°C20 Feb 2018	-28.3°C9 Feb 1948	53 mm13 Feb 1948	157 mm2018 · driest 6 mm in 1987	109
March	29.4°C22 Mar 2012	-23.9°C9 Mar 1984	67 mm10 Mar 1964	227 mm1964 · driest 19 mm in 1941	109
April	31.7°C11 Apr 1930	-13.3°C1 Apr 1923	72 mm13 Apr 1972	205 mm1972 · driest 11 mm in 1962	109
May	35.0°C27 May 2012	-5.6°C10 May 1966	70 mm23 May 2026	251 mm1956 · driest 9 mm in 1965	109
June	38.3°C25 Jun 1988	2.2°C11 Jun 1972	122 mm2 Jun 1997	267 mm2018 · driest 18 mm in 1962	109
July	42.8°C14 Jul 1936	5.6°C4 Jul 1968	89 mm20 Jul 2002	253 mm1992 · driest 8 mm in 1974	109
August	40.6°C5 Aug 1918	2.2°C30 Aug 1946	83 mm10 Aug 1931	234 mm1931 · driest 15 mm in 1983	109
September	38.9°C2 Sep 1953	-2.8°C29 Sep 1942	94 mm2 Sep 1922	235 mm1926 · driest 3 mm in 1978	109
October	33.3°C2 Oct 2019	-11.1°C29 Oct 1925	71 mm22 Oct 1929	171 mm1926 · driest 0 mm in 1963	109
November	26.7°C1 Nov 2016	-21.1°C30 Nov 1958	58 mm20 Nov 1950	216 mm1985 · driest 2 mm in 1917	109
December	23.3°C5 Dec 2001	-28.9°C27 Dec 1950	51 mm22 Dec 2013	222 mm1990 · driest 14 mm in 1955	107

Typical days per month at MARYSVILLE, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	26	2	5
February	0	0	23	2	4
March	<1	0	19	3	2
April	4	<1	5	4	<1
May	13	4	0	4	0
June	23	10	0	4	0
July	29	14	0	4	0
August	27	11	0	3	0
September	17	5	<1	2	0
October	5	<1	2	2	0
November	<1	0	14	2	<1
December	0	0	24	3	4

How often, not how much — every day in MARYSVILLE’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%	28%	7%	32%	-1.9–5.1°C
February	<1%	27%	6%	30%	0.0–7.2°C
March	8%	30%	9%	37%	6.1–13.8°C
April	25%	33%	11%	42%	14.2–19.5°C
May	50%	34%	12%	43%	19.6–25.7°C
June	68%	30%	12%	35%	25.2–29.1°C
July	73%	27%	11%	29%	27.6–31.4°C
August	76%	24%	9%	22%	26.7–30.4°C
September	68%	23%	8%	22%	22.8–27.4°C
October	36%	23%	7%	24%	16.0–21.3°C
November	6%	28%	8%	30%	7.6–13.3°C
December	<1%	27%	7%	30%	0.0–7.2°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.

1917Each stripe is one year’s mean temperature against the 103-year average. Warmest: 2024. Coolest: 1917.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5151891
NOAA station: USC00334979 · MARYSVILLE
Station distance: 20.6 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 28 usable years
Daylight: Calculated from latitude 40.30°, 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 MARYSVILLE is what differs

Marysville→Plain City→New California→Milford Center→Ostrander→Woodstock→

Or put two places side by side: Delaware vs Marysville

Best time to visitDelaware.