United States · 1991–2020

Best time to visit
Saint Mary.

September leads for comfortable weather in Saint Mary: typically 26.3°C by day, 11.6°C at night, with 71 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high26.3°C

Typical low11.6°C

Rain in September71 mm

Comfort

September

September · May · June

79climate match

Beach

August

August · July · June

72climate match

Outdoors

October

October · April · September

82climate match

The weakest month is January, scoring 5 against September’s 79 — days reach only 1.8°C, 22° below the 24°C the score treats as ideal, and nights drop to -10.4°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

51.8° / -10.4°

Feb

54.5° / -8.2°

Mar

2411.6° / -1.9°

Apr

4917.6° / 3.7°

May

7023.2° / 10.4°

Jun

6828.4° / 16.2°

Jul

5730.9° / 18.5°

Aug

6530° / 17.2°

Sep

7926.3° / 11.6°

Oct

6019.6° / 4.3°

Nov

2411° / -2.3°

Dec

54.2° / -7.9°

Monthly climate evidence for Saint Mary — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	1.8°C	-10.4°C	21 mm	3.8	9 h 35	5	Strong coverage
February	4.5°C	-8.2°C	29 mm	4.2	10 h 36	5	Strong coverage
March	11.6°C	-1.9°C	53 mm	5.7	11 h 49	24	Strong coverage
April	17.6°C	3.7°C	75 mm	7.6	13 h 13	49	Strong coverage
May	23.2°C	10.4°C	133 mm	8.8	14 h 24	70	Strong coverage
June	28.4°C	16.2°C	110 mm	8.1	15 h 02	68	Strong coverage
July	30.9°C	18.5°C	103 mm	7.7	14 h 47	57	Strong coverage
August	30°C	17.2°C	92 mm	6.9	13 h 46	65	Strong coverage
September	26.3°C	11.6°C	71 mm	5.9	12 h 25	79	Strong coverage
October	19.6°C	4.3°C	63 mm	5.4	11 h 03	60	Strong coverage
November	11°C	-2.3°C	40 mm	4.5	9 h 53	24	Strong coverage
December	4.2°C	-7.9°C	32 mm	3.9	9 h 18	5	Strong coverage

What has changed

Saint Mary runs +0.4°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

0.0

Mar

+2.0

Apr

-0.2

May

-0.7

Jun

+0.1

Jul

-1.3

Aug

-0.8

Sep

+1.4

Oct

+0.1

Nov

+0.9

Dec

+2.3

September daytime highs, 2011–2024. Last recorded: 29.0°C.

Records at TECUMSEH 1S, 1893–2025
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	22.2°C25 Jan 1981	-32.8°C4 Jan 1947	39 mm3 Jan 1949	97 mm1949 · driest 0 mm in 1986	125
February	27.8°C27 Feb 2024	-36.7°C16 Feb 2021	51 mm6 Feb 1928	104 mm2001 · driest 0 mm in 1977	126
March	35.6°C22 Mar 1910	-30.0°C11 Mar 1948	61 mm24 Mar 1957	177 mm1973 · driest 0 mm in 1910	128
April	37.2°C22 Apr 1902	-16.7°C3 Apr 1975	63 mm25 Apr 2008	193 mm1984 · driest 0 mm in 1910	126
May	40.6°C31 May 1934	-6.1°C4 May 1907	149 mm21 May 1908	348 mm2001 · driest 27 mm in 1925	127
June	42.2°C29 Jun 1911	1.1°C7 Jun 1935	127 mm24 Jun 1963	397 mm1943 · driest 12 mm in 1911	125
July	44.4°C5 Jul 1911	5.0°C5 Jul 1972	138 mm22 Jul 1978	355 mm1993 · driest 3 mm in 1919	127
August	43.3°C4 Aug 1913	3.3°C29 Aug 1946	148 mm13 Aug 1982	332 mm1952 · driest 4 mm in 1976	126
September	41.7°C5 Sep 1913	-5.0°C30 Sep 1895	115 mm26 Sep 1973	303 mm1973 · driest 5 mm in 1899	129
October	36.7°C5 Oct 1947	-17.8°C30 Oct 1925	89 mm1 Oct 1894	184 mm2007 · driest 0 mm in 1958	125
November	30.0°C25 Nov 1896	-23.3°C28 Nov 1952	85 mm3 Nov 1938	148 mm1928 · driest 0 mm in 1936	127
December	25.0°C23 Dec 1964	-33.9°C23 Dec 1989	68 mm13 Dec 2015	148 mm2015 · driest 0 mm in 1905	128

Typical days per month at TECUMSEH 1S, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	30	<1	3
February	<1	0	26	<1	3
March	2	<1	21	2	1
April	5	<1	8	3	<1
May	13	4	<1	4	0
June	25	12	0	4	0
July	29	19	0	3	0
August	28	17	0	3	0
September	19	8	<1	2	0
October	7	2	8	2	<1
November	<1	0	21	1	1
December	0	0	30	1	2

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

How often, not how much — every day in TECUMSEH 1S’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%	12%	2%	6%	-2.7–6.4°C
February	2%	14%	3%	10%	-0.5–9.0°C
March	14%	18%	6%	15%	6.5–14.9°C
April	34%	25%	9%	26%	15.5–21.0°C
May	57%	29%	12%	34%	21.2–26.4°C
June	71%	28%	13%	31%	26.5–31.4°C
July	77%	23%	10%	22%	29.4–34.7°C
August	78%	22%	10%	20%	28.6–33.5°C
September	71%	21%	10%	19%	23.7–29.3°C
October	48%	16%	6%	14%	17.0–22.8°C
November	11%	14%	4%	8%	8.0–14.3°C
December	<1%	13%	3%	7%	0.1–7.7°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.

1898Each stripe is one year’s mean temperature against the 117-year average. Warmest: 1921. Coolest: 1929.2024

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5077089
NOAA station: USC00258465 · TECUMSEH 1S
Station distance: 11.2 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 29 usable years
Daylight: Calculated from latitude 40.42°, 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 TECUMSEH 1S is what differs

Tecumseh→Sterling→Johnson→Cook→Graf (historical)→Helena (historical)→

Or put two places side by side: Saint Mary vs Tecumseh

Best time to visitSaint Mary.