United States · 1991–2020

Best time to visit
McLean.

September leads for comfortable weather in McLean: typically 25.3°C by day, 10.2°C at night, with 81 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high25.3°C

Typical low10.2°C

Rain in September81 mm

Comfort

September

September · June · May

78climate match

Beach

July

July · August · June

75climate match

Outdoors

October

October · May · September

78climate match

The weakest month is January, scoring 5 against September’s 78 — days reach only -0.1°C, 24° below the 24°C the score treats as ideal, and nights drop to -11.6°C.

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° / -11.6°

Feb

53.2° / -8.8°

Mar

149.3° / -4.2°

Apr

4316.4° / 2.3°

May

7122.7° / 8.8°

Jun

7427.7° / 14.5°

Jul

6730.5° / 17.1°

Aug

7129.4° / 16°

Sep

7825.3° / 10.2°

Oct

5618.2° / 3.4°

Nov

128° / -4.3°

Dec

51.7° / -9.2°

Monthly climate evidence for McLean — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	-0.1°C	-11.6°C	13 mm	3.1	9 h 24	5	Good coverage
February	3.2°C	-8.8°C	17 mm	3	10 h 29	5	Good coverage
March	9.3°C	-4.2°C	40 mm	5.1	11 h 48	14	Good coverage
April	16.4°C	2.3°C	73 mm	6.8	13 h 18	43	Good coverage
May	22.7°C	8.8°C	99 mm	8.5	14 h 34	71	Good coverage
June	27.7°C	14.5°C	96 mm	7.9	15 h 16	74	Good coverage
July	30.5°C	17.1°C	73 mm	6.2	14 h 59	67	Good coverage
August	29.4°C	16°C	85 mm	6	13 h 54	71	Good coverage
September	25.3°C	10.2°C	81 mm	5.5	12 h 26	78	Good coverage
October	18.2°C	3.4°C	52 mm	4.7	10 h 59	56	Good coverage
November	8°C	-4.3°C	35 mm	3.3	9 h 43	12	Good coverage
December	1.7°C	-9.2°C	17 mm	3.1	9 h 05	5	Good coverage

Records at OSMOND, 1938–2008
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	22.2°C24 Jan 1981	-35.6°C19 Jan 1970	24 mm30 Jan 1947	47 mm1944 · driest 0 mm in 1987	68
February	23.9°C21 Feb 1982	-37.2°C28 Feb 1962	49 mm19 Feb 1971	89 mm1971 · driest 0 mm in 1996	69
March	33.9°C30 Mar 1943	-30.0°C4 Mar 1960	58 mm22 Mar 1979	180 mm1987 · driest 5 mm in 1994	69
April	35.0°C21 Apr 1980	-19.4°C3 Apr 1975	66 mm23 Apr 1944	218 mm1984 · driest 6 mm in 1981	68
May	38.9°C25 May 1967	-6.7°C2 May 1967	131 mm21 May 1949	293 mm1944 · driest 14 mm in 1966	67
June	41.1°C14 Jun 1979	1.7°C4 Jun 1951	90 mm26 Jun 1985	289 mm1967 · driest 16 mm in 1995	68
July	43.3°C11 Jul 1954	3.3°C30 Jul 1971	85 mm24 Jul 1987	264 mm1993 · driest 8 mm in 2002	68
August	42.2°C16 Aug 1983	0.0°C31 Aug 1987	112 mm28 Aug 1960	187 mm1951 · driest 5 mm in 1991	68
September	38.9°C8 Sep 1940	-5.6°C29 Sep 1984	86 mm14 Sep 2004	200 mm1973 · driest 5 mm in 1998	69
October	33.9°C1 Oct 1963	-12.2°C19 Oct 1972	92 mm16 Oct 1968	154 mm1968 · driest 0 mm in 1958	68
November	27.2°C9 Nov 2006	-29.4°C14 Nov 1959	58 mm4 Nov 1959	96 mm1996 · driest 0 mm in 1980	68
December	21.1°C16 Dec 1962	-33.3°C22 Dec 1989	42 mm3 Dec 1953	84 mm2006 · driest 0 mm in 1976	66

Typical days per month at OSMOND, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	28	<1	3
February	0	0	24	<1	3
March	<1	0	23	1	2
April	3	1	10	3	<1
May	11	3	<1	4	0
June	22	10	0	3	0
July	26	16	0	3	0
August	26	14	0	3	0
September	16	7	<1	3	0
October	5	1	8	2	<1
November	<1	0	23	1	2
December	0	0	27	<1	4

How often, not how much — every day in OSMOND’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%	10%	1%	4%	-4.5–5.3°C
February	1%	12%	2%	9%	-2.4–7.5°C
March	9%	18%	4%	15%	3.4–12.6°C
April	33%	23%	8%	25%	13.1–20.6°C
May	58%	27%	11%	29%	20.8–25.9°C
June	71%	26%	11%	28%	26.0–30.8°C
July	79%	20%	8%	17%	29.2–33.3°C
August	79%	20%	8%	17%	28.3–32.3°C
September	71%	19%	7%	16%	22.2–28.0°C
October	44%	13%	4%	9%	16.1–21.6°C
November	7%	11%	3%	6%	4.9–11.8°C
December	<1%	11%	1%	6%	-2.4–5.6°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.

1941Each stripe is one year’s mean temperature against the 58-year average. Warmest: 1990. Coolest: 1993.2007

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5072823
NOAA station: USC00256395 · OSMOND
Station distance: 11 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 17 usable years
Daylight: Calculated from latitude 42.39°, 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 OSMOND is what differs

Pierce→Randolph→Osmond→Wausa→Magnet→Foster→

Or put two places side by side: McLean vs Pierce

Best time to visitMcLean.