United States · 1991–2020

Best time to visit
Brown Deer.

September leads for comfortable weather in Brown Deer: typically 23.9°C by day, 12°C at night, with 75 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high23.9°C

Typical low12°C

Rain in September75 mm

Comfort

September

September · June · August

85climate match

Beach

July

July · August · June

75climate match

Outdoors

May

May · September · October

78climate match

The weakest month is January, scoring 5 against September’s 85 — days reach only -0.7°C, 25° 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

5-0.7° / -9.7°

Feb

51.5° / -8.1°

Mar

97.4° / -3.1°

Apr

3114° / 2.5°

May

6320.5° / 8.7°

Jun

7526.1° / 14.4°

Jul

6928.7° / 17.3°

Aug

7327.6° / 16.6°

Sep

8523.9° / 12°

Oct

5016.7° / 5.6°

Nov

158.7° / -0.7°

Dec

52.1° / -6.3°

Monthly climate evidence for Brown Deer — daylight is calculated from latitude, everything else is measured, sea temperature from the nearest open water 8 km away
Month	Day	Night	Rain	Wet days	Sea	Daylight	Comfort	Coverage
January	-0.7°C	-9.7°C	36 mm	6.8	3.3°C	9 h 19	5	Strong coverage
February	1.5°C	-8.1°C	39 mm	5.9	2.1°C	10 h 27	5	Strong coverage
March	7.4°C	-3.1°C	43 mm	6.3	2.0°C	11 h 47	9	Strong coverage
April	14°C	2.5°C	96 mm	8.8	3.2°C	13 h 20	31	Strong coverage
May	20.5°C	8.7°C	93 mm	9.8	5.8°C	14 h 38	63	Strong coverage
June	26.1°C	14.4°C	122 mm	9	12.3°C	15 h 21	75	Strong coverage
July	28.7°C	17.3°C	89 mm	7.4	19.3°C	15 h 05	69	Strong coverage
August	27.6°C	16.6°C	93 mm	7.8	21.1°C	13 h 57	73	Strong coverage
September	23.9°C	12°C	75 mm	7	18.8°C	12 h 27	85	Strong coverage
October	16.7°C	5.6°C	67 mm	7.6	13.1°C	10 h 57	50	Strong coverage
November	8.7°C	-0.7°C	52 mm	6.7	8.0°C	9 h 39	15	Strong coverage
December	2.1°C	-6.3°C	45 mm	7	5.1°C	9 h 00	5	Strong coverage

What has changed

Brown Deer runs +0.1°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

+1.9

Feb

+0.5

Mar

+0.5

Apr

-1.7

May

-0.8

Jun

-1.3

Jul

-0.7

Aug

-0.6

Sep

+0.6

Oct

+0.5

Nov

+0.4

Dec

+2.5

September daytime highs, 2011–2018. Last recorded: 23.8°C.

Records at MT MARY COLLEGE, 1946–2019
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	15.6°C30 Jan 2013	-32.8°C30 Jan 1951	40 mm30 Jan 1947	111 mm1965 · driest 5 mm in 1961	72
February	21.7°C23 Feb 2017	-31.7°C3 Feb 1996	42 mm12 Feb 2019	100 mm2019 · driest 0 mm in 1969	73
March	30.0°C22 Mar 2012	-26.1°C1 Mar 1962	56 mm30 Mar 1960	153 mm1976 · driest 3 mm in 1968	72
April	32.2°C18 Apr 2002	-11.7°C3 Apr 1954	98 mm21 Apr 1973	217 mm1973 · driest 27 mm in 1997	72
May	35.0°C31 May 1988	-6.7°C9 May 1947	74 mm13 May 1978	248 mm2004 · driest 9 mm in 1988	72
June	40.0°C25 Jun 1988	0.0°C2 Jun 1956	141 mm21 Jun 1997	259 mm1968 · driest 15 mm in 2012	71
July	42.2°C13 Jul 1995	4.4°C6 Jul 1965	162 mm18 Jul 1964	337 mm2010 · driest 16 mm in 2009	72
August	42.2°C1 Aug 1988	5.0°C1 Aug 1947	97 mm7 Aug 1998	207 mm2018 · driest 15 mm in 1948	72
September	37.8°C1 Sep 1953	-2.8°C20 Sep 1956	78 mm18 Sep 1972	220 mm1986 · driest 1 mm in 1979	72
October	32.2°C6 Oct 2007	-8.9°C18 Oct 1948	60 mm4 Oct 1991	152 mm1959 · driest 3 mm in 1952	73
November	25.6°C4 Nov 2015	-22.2°C25 Nov 1950	63 mm1 Nov 1982	206 mm1985 · driest 4 mm in 2007	73
December	20.0°C5 Dec 2001	-30.0°C24 Dec 1983	42 mm15 Dec 1971	138 mm2015 · driest 6 mm in 1958	73

Typical days per month at MT MARY COLLEGE, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	28	<1	7
February	0	0	26	1	6
March	<1	0	23	2	3
April	2	<1	9	3	<1
May	8	2	<1	3	0
June	18	7	0	4	0
July	25	12	0	3	0
August	24	8	0	3	0
September	13	4	<1	3	0
October	3	<1	4	2	0
November	0	0	17	2	1
December	0	0	26	1	6

How often, not how much — every day in MT MARY COLLEGE’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%	20%	4%	18%	-5.1–1.9°C
February	<1%	18%	4%	15%	-2.4–4.6°C
March	3%	22%	6%	20%	3.0–9.7°C
April	15%	29%	10%	34%	11.0–16.7°C
May	41%	29%	9%	34%	17.8–23.4°C
June	65%	29%	11%	34%	24.0–28.1°C
July	75%	24%	9%	24%	26.9–31.0°C
August	74%	25%	10%	25%	25.7–29.5°C
September	61%	24%	9%	24%	21.7–25.6°C
October	23%	23%	7%	25%	13.6–19.2°C
November	3%	22%	6%	19%	4.6–11.2°C
December	0%	21%	4%	19%	-2.5–4.3°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.

1947Each stripe is one year’s mean temperature against the 71-year average. Warmest: 2012. Coolest: 1951.2018

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 5246917
NOAA station: USC00475474 · MT MARY COLLEGE
Station distance: 11.4 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 27 usable years
Daylight: Calculated from latitude 43.16°, mid-month, sunrise to sunset including refraction. Not a station measurement.
Sea temperature: NOAA OISST v2.1 1991–2020 monthly climatology, nearest open water 8 km from the place centre. A sheltered bay can run warmer than the open sea it is measured from.
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 MT MARY COLLEGE is what differs

Wauwatosa→Whitefish Bay→Shorewood→Glendale→Fox Point→Elm Grove→

Or put two places side by side: Brown Deer vs Wauwatosa

Best time to visitBrown Deer.

September

July

May

The whole year,without the guesswork.

Brown Deer runs +0.1°Con the 1961–1990 baseline.

Nearby, measured,and named.

Best time to visit
Brown Deer.

The whole year,
without the guesswork.

Brown Deer runs +0.1°C
on the 1961–1990 baseline.

Nearby, measured,
and named.