United States · 1991–2020

Best time to visit
Plainfield.

September leads for comfortable weather in Plainfield: typically 23.5°C by day, 10.1°C at night, with 96 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high23.5°C

Typical low10.1°C

Rain in September96 mm

Comfort

September

September · August · June

77climate match

Beach

July

July · August · June

65climate match

Outdoors

September

September · May · October

73climate match

The weakest month is January, scoring 5 against September’s 77 — days reach only -4°C, 28° 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

5-4° / -13.8°

Feb

5-1.6° / -11.3°

Mar

56° / -4.5°

Apr

2914.2° / 1.8°

May

5921.1° / 8.8°

Jun

6826.4° / 14.7°

Jul

6828.2° / 16.4°

Aug

7627.1° / 15°

Sep

7723.5° / 10.1°

Oct

4416° / 3.3°

Nov

56.8° / -3.6°

Dec

5-0.8° / -9.8°

Monthly climate evidence for Plainfield — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	-4°C	-13.8°C	29 mm	5.2	9 h 21	5	Strong coverage
February	-1.6°C	-11.3°C	27 mm	5.3	10 h 28	5	Strong coverage
March	6°C	-4.5°C	50 mm	6.5	11 h 47	5	Strong coverage
April	14.2°C	1.8°C	102 mm	9	13 h 19	29	Strong coverage
May	21.1°C	8.8°C	130 mm	10.5	14 h 37	59	Strong coverage
June	26.4°C	14.7°C	154 mm	10	15 h 19	68	Strong coverage
July	28.2°C	16.4°C	120 mm	7.5	15 h 02	68	Strong coverage
August	27.1°C	15°C	105 mm	7.5	13 h 55	76	Strong coverage
September	23.5°C	10.1°C	96 mm	7.6	12 h 26	77	Strong coverage
October	16°C	3.3°C	74 mm	6.9	10 h 58	44	Strong coverage
November	6.8°C	-3.6°C	53 mm	5.5	9 h 40	5	Strong coverage
December	-0.8°C	-9.8°C	41 mm	5.9	9 h 02	5	Strong coverage

What has changed

Plainfield runs +0.0°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

+0.8

Feb

-1.6

Mar

+0.2

Apr

-1.1

May

-0.9

Jun

+0.3

Jul

-0.1

Aug

-0.1

Sep

+1.3

Oct

-0.6

Nov

+0.1

Dec

+2.2

September daytime highs, 2011–2020. Last recorded: 22.3°C.

Records at TRIPOLI, 1946–2021
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	16.7°C27 Jan 2002	-35.6°C21 Jan 1970	41 mm22 Jan 2018	69 mm2017 · driest 0 mm in 1948	72
February	20.0°C23 Feb 2017	-35.6°C2 Feb 1996	39 mm18 Feb 1961	84 mm1971 · driest 0 mm in 1958	72
March	28.9°C30 Mar 1986	-32.8°C1 Mar 1962	47 mm26 Mar 2004	173 mm1951 · driest 1 mm in 1994	71
April	35.6°C22 Apr 1980	-17.8°C5 Apr 1982	140 mm29 Apr 1951	280 mm2008 · driest 11 mm in 2021	70
May	35.6°C15 May 2013	-4.4°C3 May 2005	141 mm17 May 1999	273 mm1982 · driest 34 mm in 1994	70
June	38.9°C26 Jun 1980	2.2°C1 Jun 1993	111 mm26 Jun 1951	271 mm2018 · driest 29 mm in 1955	72
July	38.3°C26 Jul 2012	6.1°C31 Jul 1971	131 mm17 Jul 1968	285 mm1968 · driest 23 mm in 1975	71
August	40.0°C18 Aug 1988	3.3°C20 Aug 1950	140 mm31 Aug 1981	388 mm1979 · driest 11 mm in 2003	70
September	36.7°C9 Sep 1955	-3.9°C29 Sep 1949	125 mm11 Sep 2006	361 mm2018 · driest 10 mm in 1966	72
October	33.9°C4 Oct 1997	-12.2°C19 Oct 1972	86 mm9 Oct 1970	176 mm1954 · driest 0 mm in 1952	73
November	26.1°C9 Nov 1999	-26.1°C26 Nov 1977	79 mm1 Nov 1991	149 mm1991 · driest 1 mm in 1976	72
December	18.3°C6 Dec 2001	-33.3°C25 Dec 2000	76 mm13 Dec 2015	192 mm2015 · driest 4 mm in 2017	72

Typical days per month at TRIPOLI, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	30	<1	6
February	0	0	27	<1	5
March	<1	0	25	2	3
April	2	<1	11	4	1
May	9	2	1	5	0
June	20	7	0	5	0
July	27	11	0	3	0
August	24	7	0	3	0
September	13	3	<1	3	0
October	3	<1	9	2	<1
November	<1	0	23	2	2
December	0	0	30	1	5

The best month has moved. On the 1961–1990 numbers the strongest month here was September (scoring 80); on 2011–2025 it is August (81). Both are scored the same way, from the same station — only the climate underneath changed.

How often, not how much — every day in TRIPOLI’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%	16%	2%	11%	-8.5–-0.1°C
February	<1%	16%	3%	13%	-5.7–3.2°C
March	3%	22%	6%	22%	2.0–9.5°C
April	18%	29%	11%	36%	11.3–17.1°C
May	45%	33%	14%	43%	19.3–24.3°C
June	67%	31%	14%	35%	24.7–28.7°C
July	74%	25%	11%	27%	26.7–30.5°C
August	75%	25%	12%	25%	25.5–29.3°C
September	60%	24%	10%	27%	21.3–26.1°C
October	27%	21%	7%	20%	13.7–19.9°C
November	3%	18%	5%	13%	2.7–10.1°C
December	0%	18%	3%	12%	-4.6–3.0°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.

1949Each stripe is one year’s mean temperature against the 62-year average. Warmest: 2012. Coolest: 2014.2020

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4871385
NOAA station: USC00138339 · TRIPOLI
Station distance: 23.1 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 28 usable years
Daylight: Calculated from latitude 42.85°, 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 TRIPOLI is what differs

Sumner→Tripoli→Readlyn→Frederika→Artesian→Bremer→

Or put two places side by side: Plainfield vs Sumner

Best time to visitPlainfield.

September

July

September

The whole year,without the guesswork.

Plainfield runs +0.0°Con the 1961–1990 baseline.

Nearby, measured,and named.

Best time to visit
Plainfield.

The whole year,
without the guesswork.

Plainfield runs +0.0°C
on the 1961–1990 baseline.

Nearby, measured,
and named.