United States · 1991–2020

Best time to visit
Ashburn.

September leads for comfortable weather in Ashburn: typically 26.3°C by day, 14.6°C at night, with 95 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high26.3°C

Typical low14.6°C

Rain in September95 mm

Comfort

September

September · May · June

81climate match

Beach

August

August · July · June

78climate match

Outdoors

October

October · April · May

84climate match

The weakest month is January, scoring 5 against September’s 81 — days reach only 2.5°C, 21° 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

52.5° / -6.7°

Feb

55.2° / -5.1°

Mar

2311.3° / 0.3°

Apr

5018.2° / 6.3°

May

7723.8° / 12.4°

Jun

6528.9° / 17.7°

Jul

5531.1° / 20°

Aug

6230.5° / 19.1°

Sep

8126.3° / 14.6°

Oct

6419.6° / 8.2°

Nov

3012° / 1.9°

Dec

55.1° / -3.8°

Monthly climate evidence for Ashburn — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	2.5°C	-6.7°C	45 mm	4.7	9 h 40	5	Strong coverage
February	5.2°C	-5.1°C	48 mm	4.6	10 h 39	5	Strong coverage
March	11.3°C	0.3°C	67 mm	7.4	11 h 49	23	Strong coverage
April	18.2°C	6.3°C	103 mm	8.7	13 h 11	50	Strong coverage
May	23.8°C	12.4°C	118 mm	10	14 h 20	77	Strong coverage
June	28.9°C	17.7°C	105 mm	7.7	14 h 57	65	Strong coverage
July	31.1°C	20°C	102 mm	7	14 h 42	55	Strong coverage
August	30.5°C	19.1°C	88 mm	5.6	13 h 43	62	Strong coverage
September	26.3°C	14.6°C	95 mm	6	12 h 24	81	Strong coverage
October	19.6°C	8.2°C	76 mm	6.8	11 h 05	64	Strong coverage
November	12°C	1.9°C	62 mm	6.1	9 h 57	30	Strong coverage
December	5.1°C	-3.8°C	51 mm	5.6	9 h 23	5	Strong coverage

What has changed

Ashburn 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

+1.1

Feb

+1.1

Mar

+1.1

Apr

-0.2

May

+0.2

Jun

+0.8

Jul

+0.1

Aug

+0.3

Sep

+1.4

Oct

+0.6

Nov

+0.7

Dec

+2.4

September daytime highs, 2011–2025. Last recorded: 28.4°C.

Records at SAVERTON L&D 22, 1948–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	23.3°C24 Jan 1950	-30.0°C17 Jan 1977	76 mm29 Jan 2001	133 mm2001 · driest 2 mm in 1986	78
February	27.8°C29 Feb 1972	-28.3°C9 Feb 1979	89 mm25 Feb 2011	133 mm1997 · driest 2 mm in 1991	77
March	33.3°C22 Mar 2026	-23.9°C2 Mar 1980	63 mm18 Mar 2021	217 mm1973 · driest 8 mm in 1956	78
April	34.4°C27 Apr 2001	-6.7°C3 Apr 2018	100 mm29 Apr 1956	200 mm1994 · driest 23 mm in 2018	78
May	35.6°C25 May 1978	0.0°C10 May 1966	83 mm11 May 2010	225 mm1991 · driest 12 mm in 2005	77
June	41.7°C29 Jun 2012	7.2°C5 Jun 1993	117 mm24 Jun 1949	306 mm1949 · driest 6 mm in 1959	78
July	43.3°C14 Jul 1954	6.1°C13 Jul 1967	112 mm28 Jul 1957	430 mm1981 · driest 13 mm in 1994	78
August	44.4°C16 Aug 2007	8.3°C21 Aug 1950	83 mm28 Aug 2004	270 mm1995 · driest 6 mm in 2025	77
September	40.0°C2 Sep 2011	1.7°C30 Sep 1949	125 mm1 Sep 2003	343 mm1993 · driest 8 mm in 1956	78
October	35.0°C2 Oct 2019	-5.6°C20 Oct 1960	84 mm13 Oct 1969	254 mm1969 · driest 4 mm in 1964	78
November	28.3°C2 Nov 2016	-18.9°C30 Nov 1964	71 mm17 Nov 1958	246 mm1985 · driest 5 mm in 2008	78
December	23.9°C4 Dec 2012	-27.8°C22 Dec 1989	65 mm3 Dec 1982	177 mm2015 · driest 4 mm in 1976	77

Typical days per month at SAVERTON L&D 22, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	26	1	1
February	0	0	22	2	1
March	2	0	15	3	<1
April	5	<1	3	4	0
May	13	4	0	4	0
June	23	13	0	4	0
July	28	19	0	3	0
August	28	17	0	3	0
September	18	7	0	3	0
October	6	1	1	3	0
November	<1	0	11	2	<1
December	0	0	23	2	<1

The best month has moved. On the 1961–1990 numbers the strongest month here was May (scoring 84); on 2011–2025 it is September (84). Both are scored the same way, from the same station — only the climate underneath changed.

How often, not how much — every day in SAVERTON L&D 22’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%	17%	4%	12%	-0.9–6.0°C
February	2%	18%	5%	15%	0.4–8.7°C
March	11%	25%	8%	26%	7.7–14.6°C
April	30%	30%	11%	35%	15.4–21.3°C
May	57%	29%	12%	35%	21.5–26.7°C
June	73%	25%	11%	25%	27.1–31.4°C
July	75%	25%	10%	23%	29.7–33.7°C
August	80%	20%	9%	17%	28.1–32.3°C
September	74%	21%	9%	18%	24.2–28.7°C
October	44%	21%	8%	21%	18.0–22.4°C
November	12%	22%	7%	21%	8.5–15.1°C
December	<1%	19%	5%	16%	2.2–8.4°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.

1949Each stripe is one year’s mean temperature against the 72-year average. Warmest: 2012. Coolest: 1996.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4375187
NOAA station: USC00237578 · SAVERTON L&D 22
Station distance: 12.3 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 28 usable years
Daylight: Calculated from latitude 39.54°, 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 SAVERTON L&D 22 is what differs

Barry→New London→Hull→New Canton→Frankford→Kinderhook→

Or put two places side by side: Ashburn vs Barry

Best time to visitAshburn.

September

August

October

The whole year,without the guesswork.

Ashburn runs +0.8°Con the 1961–1990 baseline.

Nearby, measured,and named.

Best time to visit
Ashburn.

The whole year,
without the guesswork.

Ashburn runs +0.8°C
on the 1961–1990 baseline.

Nearby, measured,
and named.