United States · 1991–2020

Best time to visit
Weldon Spring.

September leads for comfortable weather in Weldon Spring: typically 26.8°C by day, 13.8°C at night, with 87 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high26.8°C

Typical low13.8°C

Rain in September87 mm

Comfort

September

September · May · October

79climate match

Beach

July

July · August · June

75climate match

Outdoors

October

October · April · September

82climate match

The weakest month is January, scoring 5 against September’s 79 — days reach only 4.4°C, 20° 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

54.4° / -5.9°

Feb

57.3° / -4°

Mar

2612.9° / 0.8°

Apr

5119.5° / 6.4°

May

7424.3° / 12.2°

Jun

6328.8° / 17.3°

Jul

5730.9° / 19.4°

Aug

6230.5° / 18.4°

Sep

7926.8° / 13.8°

Oct

6420.3° / 7.6°

Nov

2813° / 1.6°

Dec

56.8° / -3.4°

Monthly climate evidence for Weldon Spring — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	4.4°C	-5.9°C	63 mm	5.3	9 h 44	5	Strong coverage
February	7.3°C	-4°C	59 mm	5.4	10 h 41	5	Strong coverage
March	12.9°C	0.8°C	91 mm	8	11 h 50	26	Strong coverage
April	19.5°C	6.4°C	125 mm	9	13 h 09	51	Strong coverage
May	24.3°C	12.2°C	132 mm	10.3	14 h 16	74	Strong coverage
June	28.8°C	17.3°C	120 mm	8.2	14 h 51	63	Strong coverage
July	30.9°C	19.4°C	97 mm	6.6	14 h 37	57	Strong coverage
August	30.5°C	18.4°C	89 mm	6.6	13 h 40	62	Strong coverage
September	26.8°C	13.8°C	87 mm	5.4	12 h 23	79	Strong coverage
October	20.3°C	7.6°C	83 mm	6.8	11 h 07	64	Strong coverage
November	13°C	1.6°C	90 mm	6.7	10 h 01	28	Strong coverage
December	6.8°C	-3.4°C	74 mm	6.5	9 h 28	5	Strong coverage

What has changed

Weldon Spring runs +0.8°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

+1.0

Feb

+0.7

Mar

+1.3

Apr

+0.6

May

+0.2

Jun

+1.1

Jul

+0.2

Aug

0.0

Sep

+1.5

Oct

+0.3

Nov

+0.4

Dec

+2.5

September daytime highs, 2011–2025. Last recorded: 29.7°C.

Records at WELDON SPRING NWS, 1957–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	24.4°C24 Jan 1967	-30.6°C17 Jan 1977	71 mm11 Jan 2020	224 mm2005 · driest 0 mm in 1992	68
February	29.4°C14 Feb 1962	-25.6°C12 Feb 1981	69 mm10 Feb 1959	146 mm1986 · driest 0 mm in 1996	67
March	33.9°C27 Mar 2026	-23.9°C5 Mar 1978	75 mm27 Mar 2004	175 mm2004 · driest 11 mm in 1993	68
April	34.4°C19 Apr 2002	-7.8°C10 Apr 1989	107 mm30 Apr 2017	256 mm2025 · driest 3 mm in 1992	68
May	33.9°C29 May 2018	-3.3°C2 May 1989	102 mm18 May 1959	314 mm2004 · driest 10 mm in 1987	66
June	41.1°C29 Jun 2012	3.9°C1 Jun 1966	151 mm24 Jun 2000	413 mm1957 · driest 14 mm in 1974	67
July	41.7°C8 Jul 2012	6.1°C12 Jul 1996	117 mm3 Jul 1980	243 mm2008 · driest 17 mm in 1997	67
August	42.8°C18 Aug 2000	2.2°C29 Aug 1986	101 mm9 Aug 2020	194 mm1970 · driest 4 mm in 1957	69
September	38.9°C2 Sep 1984	-5.6°C25 Sep 1989	101 mm14 Sep 2008	275 mm1984 · driest 0 mm in 1979	65
October	35.0°C11 Oct 1963	-7.2°C24 Oct 1981	83 mm4 Oct 1986	328 mm2009 · driest 11 mm in 1989	66
November	29.4°C10 Nov 2022	-17.8°C30 Nov 1964	105 mm5 Nov 2024	214 mm2024 · driest 0 mm in 1976	65
December	25.6°C29 Dec 2025	-33.3°C23 Dec 1989	162 mm27 Dec 2015	340 mm2015 · driest 1 mm in 1989	67

Typical days per month at WELDON SPRING NWS, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	24	2	3
February	<1	0	21	2	3
March	2	0	14	3	2
April	6	1	3	4	<1
May	16	4	0	4	0
June	26	13	0	4	0
July	29	19	0	3	0
August	29	18	0	3	0
September	20	8	0	3	0
October	8	1	2	3	0
November	1	0	13	3	<1
December	0	0	23	2	3

The best month has moved. On the 1961–1990 numbers the strongest month here was May (scoring 82); on 2011–2025 it is September (82). Both are scored the same way, from the same station — only the climate underneath changed.

How often, not how much — every day in WELDON SPRING NWS’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	2%	17%	6%	13%	0.5–7.4°C
February	5%	19%	6%	18%	2.7–11.0°C
March	15%	27%	10%	30%	8.7–16.3°C
April	34%	29%	12%	34%	16.6–21.6°C
May	57%	30%	12%	36%	22.1–26.8°C
June	72%	26%	11%	27%	27.2–30.5°C
July	77%	23%	11%	19%	29.2–32.6°C
August	79%	21%	9%	18%	28.6–32.6°C
September	74%	20%	8%	19%	24.8–28.7°C
October	46%	22%	9%	24%	18.4–22.8°C
November	14%	22%	9%	20%	9.6–15.9°C
December	3%	19%	6%	18%	3.3–9.8°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.

1958Each stripe is one year’s mean temperature against the 48-year average. Warmest: 2012. Coolest: 1989.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4413926
NOAA station: USC00238805 · WELDON SPRING NWS
Station distance: 1.7 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 27 usable years
Daylight: Calculated from latitude 38.71°, 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 WELDON SPRING NWS is what differs

Wentzville→Lake Saint Louis→Dardenne Prairie→Cottleville→Flint Hill→New Melle→

Or put two places side by side: Weldon Spring vs Wentzville

Best time to visitWeldon Spring.