United States · 1991–2020

Best time to visit
Sullivan.

September leads for comfortable weather in Sullivan: typically 23.5°C by day, 10.9°C at night, with 86 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high23.5°C

Typical low10.9°C

Rain in September86 mm

Comfort

September

September · August · June

80climate match

Beach

July

July · August · June

67climate match

Outdoors

September

September · May · October

74climate match

The weakest month is January, scoring 5 against September’s 80 — days reach only -2.6°C, 27° 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

5-2.6° / -11.3°

Feb

5-0.4° / -9.9°

Mar

56.2° / -4.6°

Apr

2713.9° / 1.9°

May

5720.4° / 8.1°

Jun

7225.9° / 13.7°

Jul

7128.3° / 15.9°

Aug

7527.2° / 15.2°

Sep

8023.5° / 10.9°

Oct

4415.9° / 4.5°

Nov

97.6° / -2°

Dec

50.4° / -8.1°

Monthly climate evidence for Sullivan — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	-2.6°C	-11.3°C	44 mm	7.2	9 h 20	5	Strong coverage
February	-0.4°C	-9.9°C	47 mm	6.8	10 h 27	5	Good coverage
March	6.2°C	-4.6°C	53 mm	7.2	11 h 47	5	Strong coverage
April	13.9°C	1.9°C	99 mm	10.2	13 h 20	27	Strong coverage
May	20.4°C	8.1°C	114 mm	11.2	14 h 38	57	Strong coverage
June	25.9°C	13.7°C	126 mm	10	15 h 20	72	Strong coverage
July	28.3°C	15.9°C	100 mm	7.9	15 h 04	71	Strong coverage
August	27.2°C	15.2°C	101 mm	8	13 h 56	75	Strong coverage
September	23.5°C	10.9°C	86 mm	7.5	12 h 26	80	Strong coverage
October	15.9°C	4.5°C	77 mm	8.4	10 h 57	44	Strong coverage
November	7.6°C	-2°C	56 mm	6.6	9 h 40	9	Strong coverage
December	0.4°C	-8.1°C	54 mm	8	9 h 01	5	Strong coverage

Records at SULLIVAN 3 SE - WFO MKX, 1995–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	15.6°C5 Jan 1997	-34.4°C31 Jan 2019	52 mm29 Jan 2013	91 mm2013 · driest 4 mm in 2025	31
February	21.7°C27 Feb 2024	-33.9°C4 Feb 1996	42 mm27 Feb 2023	102 mm2008 · driest 3 mm in 1995	29
March	27.2°C30 Mar 1998	-25.0°C5 Mar 2002	59 mm31 Mar 1998	159 mm2024 · driest 13 mm in 1996	31
April	31.7°C19 Apr 2002	-10.6°C5 Apr 2018	61 mm23 Apr 1999	225 mm2026 · driest 32 mm in 2003	32
May	35.0°C27 May 2012	-5.6°C9 May 2020	125 mm12 May 2014	246 mm2004 · driest 19 mm in 2026	32
June	37.2°C28 Jun 2012	0.6°C2 Jun 2003	97 mm8 Jun 2008	324 mm2010 · driest 5 mm in 2012	31
July	41.1°C5 Jul 2012	5.0°C2 Jul 2001	119 mm23 Jul 2010	297 mm2010 · driest 31 mm in 2021	31
August	36.7°C1 Aug 2001	4.4°C31 Aug 2009	104 mm19 Aug 2007	325 mm2007 · driest 25 mm in 2008	31
September	35.6°C14 Sep 1998	-1.7°C15 Sep 2007	88 mm11 Sep 2022	207 mm2018 · driest 6 mm in 2017	30
October	32.2°C8 Oct 1997	-7.2°C31 Oct 2019	52 mm26 Oct 2016	145 mm1995 · driest 13 mm in 2005	30
November	23.9°C3 Nov 2015	-18.9°C29 Nov 1995	87 mm6 Nov 2005	138 mm2005 · driest 8 mm in 2007	30
December	19.4°C6 Dec 2001	-26.7°C19 Dec 2016	35 mm28 Dec 2015	131 mm2008 · driest 11 mm in 2017	31

Typical days per month at SULLIVAN 3 SE - WFO MKX, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	30	1	9
February	0	0	26	1	8
March	<1	0	25	1	5
April	2	<1	11	3	2
May	8	2	1	4	0
June	18	7	0	4	0
July	27	10	0	4	0
August	24	7	0	3	0
September	13	3	<1	3	0
October	3	<1	7	3	<1
November	0	0	20	2	3
December	0	0	28	2	8

How often, not how much — every day in SULLIVAN 3 SE - WFO MKX’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%	24%	3%	27%	-5.1–0.3°C
February	<1%	23%	4%	22%	-5.7–4.3°C
March	3%	24%	6%	30%	4.1–9.5°C
April	14%	35%	11%	48%	11.9–16.5°C
May	39%	34%	11%	42%	18.3–22.8°C
June	63%	33%	13%	37%	24.3–28.2°C
July	74%	26%	11%	24%	26.2–30.3°C
August	74%	25%	10%	24%	25.4–29.1°C
September	60%	24%	9%	31%	21.2–25.7°C
October	21%	27%	8%	29%	13.1–18.1°C
November	4%	22%	6%	22%	3.2–11.2°C
December	0%	26%	5%	27%	-3.2–4.4°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.

1995Each stripe is one year’s mean temperature against the 28-year average. Warmest: 1998. Coolest: 2014.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5274964
NOAA station: USC00478316 · SULLIVAN 3 SE - WFO MKX
Station distance: 5.9 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 23 usable years
Daylight: Calculated from latitude 43.01°, 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 SULLIVAN 3 SE - WFO MKX is what differs

Dousman→North Prairie→Eagle→Palmyra→Rome→Eagleville→

Or put two places side by side: Sullivan vs Dousman

Best time to visitSullivan.

September

July

September

The whole year,without the guesswork.

Nearby, measured,and named.

Best time to visit
Sullivan.

The whole year,
without the guesswork.

Nearby, measured,
and named.