United States · 1991–2020

Best time to visit
Bethesda.

October leads for comfortable weather in Bethesda: typically 22.8°C by day, 7.9°C at night, with 82 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortOctober

Typical high22.8°C

Typical low7.9°C

Rain in October82 mm

Comfort

October

October · September · May

73climate match

Beach

August

August · July · September

69climate match

Outdoors

October

October · April · November

75climate match

The weakest month is January, scoring 5 against October’s 73 — days reach only 9.5°C, 14° below the 24°C the score treats as ideal, and nights drop to -1.7°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

59.5° / -1.7°

Feb

1311.9° / -0.5°

Mar

3416.9° / 3.2°

Apr

6122.2° / 7.6°

May

6926.2° / 12.7°

Jun

5529.9° / 17.1°

Jul

4931.5° / 19.2°

Aug

5631.1° / 18.5°

Sep

7228.3° / 14.8°

Oct

7322.8° / 7.9°

Nov

3716.1° / 2.4°

Dec

811.2° / -0.2°

Monthly climate evidence for Bethesda — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	9.5°C	-1.7°C	126 mm	10.1	9 h 58	5	Strong coverage
February	11.9°C	-0.5°C	129 mm	10	10 h 50	13	Strong coverage
March	16.9°C	3.2°C	140 mm	10.9	11 h 51	34	Strong coverage
April	22.2°C	7.6°C	134 mm	9.9	13 h 03	61	Strong coverage
May	26.2°C	12.7°C	129 mm	10.4	14 h 02	69	Strong coverage
June	29.9°C	17.1°C	140 mm	10.3	14 h 34	55	Strong coverage
July	31.5°C	19.2°C	124 mm	10.1	14 h 22	49	Strong coverage
August	31.1°C	18.5°C	107 mm	8.1	13 h 31	56	Strong coverage
September	28.3°C	14.8°C	104 mm	6.9	12 h 22	72	Strong coverage
October	22.8°C	7.9°C	82 mm	6.7	11 h 13	73	Strong coverage
November	16.1°C	2.4°C	112 mm	7.5	10 h 13	37	Strong coverage
December	11.2°C	-0.2°C	149 mm	9.8	9 h 44	8	Strong coverage

What has changed

Bethesda runs +0.3°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

0.0

Feb

+1.2

Mar

+0.6

Apr

-0.2

May

+0.3

Jun

+0.1

Jul

+0.2

Aug

-0.6

Sep

+0.2

Oct

+0.6

Nov

-0.2

Dec

+1.6

October daytime highs, 2011–2025. Last recorded: 22.2°C.

Records at SPARTA WWTP, 1961–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	25.0°C3 Jan 2004	-26.1°C24 Jan 1963	105 mm23 Jan 2002	283 mm1974 · driest 3 mm in 2010	63
February	27.2°C24 Feb 2018	-28.9°C5 Feb 1996	89 mm6 Feb 2020	298 mm2019 · driest 13 mm in 1980	64
March	31.1°C28 Mar 2004	-14.4°C15 Mar 1993	118 mm12 Mar 1963	413 mm1975 · driest 31 mm in 1984	63
April	32.8°C24 Apr 2004	-6.1°C11 Apr 1973	81 mm8 Apr 2006	291 mm1970 · driest 7 mm in 1978	65
May	34.4°C20 May 1962	-2.2°C4 May 1971	88 mm5 May 2003	336 mm2003 · driest 33 mm in 1962	65
June	42.2°C30 Jun 2012	1.1°C1 Jun 1966	116 mm28 Jun 2018	352 mm1998 · driest 1 mm in 1988	65
July	41.1°C1 Jul 2012	8.3°C15 Jul 1967	96 mm1 Jul 1973	349 mm1967 · driest 14 mm in 1997	65
August	39.4°C21 Aug 1983	7.8°C30 Aug 1965	91 mm12 Aug 1970	227 mm1966 · driest 0 mm in 1973	62
September	37.8°C7 Sep 1990	-1.7°C30 Sep 1967	118 mm29 Sep 1964	278 mm2018 · driest 7 mm in 2008	62
October	35.6°C2 Oct 2019	-7.2°C27 Oct 1961	103 mm3 Oct 1962	235 mm2014 · driest 0 mm in 1963	62
November	32.8°C2 Nov 2003	-13.9°C24 Nov 2023	117 mm7 Nov 2017	253 mm2011 · driest 0 mm in 2009	62
December	25.6°C28 Dec 2015	-26.7°C13 Dec 1962	119 mm30 Dec 1969	449 mm1990 · driest 4 mm in 2009	63

Typical days per month at SPARTA WWTP, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	<1	0	20	4	1
February	<1	0	16	4	1
March	3	0	11	4	<1
April	11	1	3	5	0
May	21	7	0	4	0
June	28	17	0	4	0
July	30	24	0	4	0
August	30	22	0	3	0
September	25	11	0	3	0
October	13	1	3	3	0
November	2	<1	12	4	0
December	<1	0	18	5	<1

The best month has moved. On the 1961–1990 numbers the strongest month here was September (scoring 75); on 2011–2025 it is May (78). Both are scored the same way, from the same station — only the climate underneath changed.

How often, not how much — every day in SPARTA WWTP’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	3%	30%	14%	37%	5.0–12.3°C
February	8%	31%	15%	41%	6.9–15.4°C
March	26%	31%	15%	38%	13.7–19.3°C
April	48%	30%	14%	37%	20.1–24.3°C
May	63%	30%	14%	36%	23.8–27.9°C
June	71%	29%	13%	35%	27.8–31.2°C
July	69%	30%	14%	33%	29.8–32.8°C
August	77%	22%	11%	22%	29.3–32.4°C
September	76%	21%	11%	18%	26.3–30.4°C
October	60%	18%	9%	16%	20.1–24.8°C
November	24%	25%	13%	25%	13.1–18.8°C
December	4%	27%	14%	31%	7.5–13.3°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.

1962Each stripe is one year’s mean temperature against the 54-year average. Warmest: 2007. Coolest: 1976.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4605929
NOAA station: USC00408522 · SPARTA WWTP
Station distance: 15.2 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 29 usable years
Daylight: Calculated from latitude 35.82°, 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 SPARTA WWTP is what differs

Sparta→Doyle→Black Oak→Bon Air→Cassville→Clarktown→

Or put two places side by side: Bethesda vs Sparta

Best time to visitBethesda.

October

August

October

The whole year,without the guesswork.

Bethesda runs +0.3°Con the 1961–1990 baseline.

Nearby, measured,and named.

Best time to visit
Bethesda.

The whole year,
without the guesswork.

Bethesda runs +0.3°C
on the 1961–1990 baseline.

Nearby, measured,
and named.