United States · 1991–2020

Best time to visit
Floris.

September leads for comfortable weather in Floris: typically 26.3°C by day, 14.3°C at night, with 100 mm of rain. Based on measured 1991–2020 NOAA station history.

Best comfortSeptember

Typical high26.3°C

Typical low14.3°C

Rain in September100 mm

Comfort

September

September · May · June

78climate match

Beach

August

August · July · June

75climate match

Outdoors

October

October · April · May

81climate match

The weakest month is January, scoring 5 against September’s 78 — days reach only 6°C, 18° 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

56° / -3.9°

Feb

67.9° / -3°

Mar

2512.8° / 0.8°

Apr

5719.4° / 6.1°

May

7624° / 11.5°

Jun

6728.5° / 16.5°

Jul

5431° / 19.2°

Aug

6230.3° / 18.3°

Sep

7826.3° / 14.3°

Oct

6220° / 7.3°

Nov

3313.7° / 1.9°

Dec

68.2° / -1.8°

Monthly climate evidence for Floris — daylight is calculated from latitude, everything else is measured
Month	Day	Night	Rain	Wet days	Daylight	Comfort	Coverage
January	6°C	-3.9°C	75 mm	7.5	9 h 43	5	Strong coverage
February	7.9°C	-3°C	66 mm	7.2	10 h 40	6	Strong coverage
March	12.8°C	0.8°C	89 mm	8.6	11 h 50	25	Strong coverage
April	19.4°C	6.1°C	88 mm	8.4	13 h 10	57	Strong coverage
May	24°C	11.5°C	120 mm	9.9	14 h 17	76	Strong coverage
June	28.5°C	16.5°C	109 mm	8.6	14 h 53	67	Strong coverage
July	31°C	19.2°C	105 mm	8.8	14 h 39	54	Strong coverage
August	30.3°C	18.3°C	90 mm	7.2	13 h 41	62	Strong coverage
September	26.3°C	14.3°C	100 mm	7.3	12 h 24	78	Strong coverage
October	20°C	7.3°C	93 mm	6.6	11 h 07	62	Strong coverage
November	13.7°C	1.9°C	79 mm	6.7	10 h	33	Strong coverage
December	8.2°C	-1.8°C	84 mm	8	9 h 27	6	Strong coverage

What has changed

Floris runs +1.1°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

+1.5

Feb

+2.5

Mar

+1.3

Apr

+1.2

May

+0.7

Jun

+0.8

Jul

+1.2

Aug

+0.4

Sep

+0.7

Oct

+0.9

Nov

+0.2

Dec

+2.2

September daytime highs, 2011–2025. Last recorded: 27.4°C.

Records at WASHINGTON DULLES INTL AP, 1960–2026
Month	Record high	Record low	Wettest day	Wettest / driest month	Years
January	26.1°C26 Jan 2024	-27.8°C22 Jan 1984	51 mm30 Jan 2013	168 mm1979 · driest 0 mm in 1963	65
February	26.7°C23 Feb 2023	-25.6°C18 Feb 1979	59 mm16 Feb 2003	159 mm2003 · driest 0 mm in 1963	65
March	31.7°C30 Mar 1998	-18.3°C15 Mar 1993	68 mm21 Mar 2019	194 mm1993 · driest 2 mm in 2006	65
April	33.9°C6 Apr 2010	-8.3°C1 Apr 1969	101 mm30 Apr 2014	188 mm2014 · driest 9 mm in 1985	66
May	36.1°C29 May 1969	-2.2°C7 May 1970	95 mm11 May 2008	261 mm2009 · driest 9 mm in 2007	66
June	38.9°C29 Jun 2012	2.2°C8 Jun 1977	271 mm21 Jun 1972	462 mm1972 · driest 13 mm in 1988	66
July	40.6°C22 Jul 2011	5.0°C1 Jul 1988	128 mm21 Jul 2018	285 mm2018 · driest 22 mm in 1962	66
August	40.0°C20 Aug 1983	3.3°C29 Aug 1982	119 mm11 Aug 1984	272 mm1984 · driest 6 mm in 1962	64
September	37.8°C6 Sep 2023	-1.1°C24 Sep 1974	140 mm14 Sep 1966	286 mm1975 · driest 4 mm in 2005	64
October	35.6°C2 Oct 2019	-9.4°C24 Oct 1969	108 mm29 Oct 2012	234 mm2005 · driest 0 mm in 1963	63
November	28.9°C2 Nov 1971	-12.8°C24 Nov 1989	66 mm27 Nov 1993	199 mm1963 · driest 6 mm in 1981	63
December	26.1°C6 Dec 1998	-20.0°C25 Dec 1989	74 mm18 Dec 1977	171 mm1969 · driest 0 mm in 1962	65

Typical days per month at WASHINGTON DULLES INTL AP, 1991–2020
Month	Days 25°C+	Days 30°C+	Frost nights	Heavy rain (10 mm+)	Snow days
January	0	0	24	3	3
February	<1	0	21	2	3
March	1	<1	15	3	2
April	6	1	4	3	<1
May	15	5	<1	4	0
June	25	13	0	3	0
July	30	21	0	3	0
August	29	18	0	3	0
September	19	7	0	3	0
October	6	<1	2	3	0
November	<1	0	13	3	<1
December	<1	0	22	3	2

How often, not how much — every day in WASHINGTON DULLES INTL AP’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%	24%	8%	25%	2.3–8.6°C
February	3%	25%	8%	27%	3.7–11.0°C
March	14%	27%	9%	28%	9.9–15.9°C
April	35%	27%	9%	30%	16.9–21.3°C
May	57%	32%	13%	40%	21.7–26.0°C
June	72%	27%	10%	31%	26.9–29.8°C
July	73%	27%	10%	29%	29.0–33.0°C
August	76%	24%	9%	23%	28.4–31.9°C
September	74%	23%	9%	22%	24.6–28.3°C
October	44%	20%	9%	18%	18.1–22.2°C
November	13%	23%	9%	22%	11.0–16.2°C
December	2%	25%	9%	25%	4.0–11.0°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.

1963Each stripe is one year’s mean temperature against the 63-year average. Warmest: 2024. Coolest: 1976.2025

The evidence behind this page

Nearby, measured,
and named.

Place identity: GeoNames 4759430
NOAA station: USW00093738 · WASHINGTON DULLES INTL AP
Station distance: 3 km from the place centre
Climate period: 1991–2020
Minimum month coverage: 30 usable years
Daylight: Calculated from latitude 38.94°, 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 WASHINGTON DULLES INTL AP is what differs

Centreville→Oak Hill→Herndon→South Riding→Chantilly→Dranesville→

Or put two places side by side: Floris vs Centreville

Best time to visitFloris.