Point Forecast: Fairfax VA  38.85N 77.29W (Elev. 400 ft)	Last Update: 4:53 pm EDT Sep 10, 2026

[hide menu]

Weather Elements Fire Weather Aviation Weather Temperature (°F) Dewpoint (°F) Heat Index (°F) Surface Wind  ktmphkm/hm/s Sky Cover (%) Precipitation Potential (%) Relative Humidity (%) Rain Thunder Fog Mixing Height  x100ftx100m Trans. Wind  ktmphkm/hm/s Vent Rate (x1000 mph-ft) Atmospheric Dispersion Index Low Visibility Occurrence Risk Index Ceiling Height Visibility

48-Hour Period Starting: 6pm Thu, Sep 10 20267pm Thu, Sep 10 20268pm Thu, Sep 10 20269pm Thu, Sep 10 202610pm Thu, Sep 10 202611pm Thu, Sep 10 202612am Fri, Sep 11 20261am Fri, Sep 11 20262am Fri, Sep 11 20263am Fri, Sep 11 20264am Fri, Sep 11 20265am Fri, Sep 11 20266am Fri, Sep 11 20267am Fri, Sep 11 20268am Fri, Sep 11 20269am Fri, Sep 11 202610am Fri, Sep 11 202611am Fri, Sep 11 202612pm Fri, Sep 11 20261pm Fri, Sep 11 20262pm Fri, Sep 11 20263pm Fri, Sep 11 20264pm Fri, Sep 11 20265pm Fri, Sep 11 20266pm Fri, Sep 11 20267pm Fri, Sep 11 20268pm Fri, Sep 11 20269pm Fri, Sep 11 202610pm Fri, Sep 11 202611pm Fri, Sep 11 202612am Sat, Sep 12 20261am Sat, Sep 12 20262am Sat, Sep 12 20263am Sat, Sep 12 20264am Sat, Sep 12 20265am Sat, Sep 12 20266am Sat, Sep 12 20267am Sat, Sep 12 20268am Sat, Sep 12 20269am Sat, Sep 12 202610am Sat, Sep 12 202611am Sat, Sep 12 202612pm Sat, Sep 12 20261pm Sat, Sep 12 20262pm Sat, Sep 12 20263pm Sat, Sep 12 20264pm Sat, Sep 12 20265pm Sat, Sep 12 20266pm Sat, Sep 12 20267pm Sat, Sep 12 20268pm Sat, Sep 12 20269pm Sat, Sep 12 202610pm Sat, Sep 12 202611pm Sat, Sep 12 202612am Sun, Sep 13 20261am Sun, Sep 13 20262am Sun, Sep 13 20263am Sun, Sep 13 20264am Sun, Sep 13 20265am Sun, Sep 13 20266am Sun, Sep 13 20267am Sun, Sep 13 20268am Sun, Sep 13 20269am Sun, Sep 13 202610am Sun, Sep 13 202611am Sun, Sep 13 202612pm Sun, Sep 13 20261pm Sun, Sep 13 20262pm Sun, Sep 13 20263pm Sun, Sep 13 20264pm Sun, Sep 13 20265pm Sun, Sep 13 20266pm Sun, Sep 13 20267pm Sun, Sep 13 20268pm Sun, Sep 13 20269pm Sun, Sep 13 202610pm Sun, Sep 13 202611pm Sun, Sep 13 202612am Mon, Sep 14 20261am Mon, Sep 14 20262am Mon, Sep 14 20263am Mon, Sep 14 20264am Mon, Sep 14 20265am Mon, Sep 14 20266am Mon, Sep 14 20267am Mon, Sep 14 20268am Mon, Sep 14 20269am Mon, Sep 14 202610am Mon, Sep 14 202611am Mon, Sep 14 202612pm Mon, Sep 14 20261pm Mon, Sep 14 20262pm Mon, Sep 14 20263pm Mon, Sep 14 20264pm Mon, Sep 14 20265pm Mon, Sep 14 20266pm Mon, Sep 14 20267pm Mon, Sep 14 20268pm Mon, Sep 14 20269pm Mon, Sep 14 202610pm Mon, Sep 14 202611pm Mon, Sep 14 202612am Tue, Sep 15 20261am Tue, Sep 15 20262am Tue, Sep 15 20263am Tue, Sep 15 20264am Tue, Sep 15 20265am Tue, Sep 15 2026

Date	09/10						09/11
Hour (EDT)	18	19	20	21	22	23	00	01	02	03	04	05	06	07	08	09	10	11	12	13	14	15	16	17
Temperature (°F)	86	84	80	78	76	76	75	74	73	73	72	71	70	70	68	70	73	74	75	77	77	78	79	77
Dewpoint (°F)	70	70	70	70	70	70	69	69	69	69	68	68	68	68	67	67	66	66	66	66	66	66	66	66
Heat Index (°F)	91	88	83	78	76	76	75												75	77	77	78	79	77
Surface Wind (mph)	5	3	2	2	2	2	2	2	2	3	3	3	3	3	5	3	5	6	5	5	5	3	3	3
Wind Dir	W	N	NW	NW	NW	NW	NW	NW	N	N	N	N	N	N	N	N	N	N	N	N	N	NE	NE	NE
Gust
Sky Cover (%)	57	62	67	48	56	66	77	78	80	82	81	87	90	86	79	75	78	80	79	80	74	67	73	67
Precipitation Potential (%)	7	8	11	14	15	19	25	31	32	34	40	48	46	38	17	10	8	6	4	4	5	7	8	4
Relative Humidity (%)	59	63	72	76	82	82	82	84	87	87	87	90	93	93	97	90	79	76	74	69	69	67	64	69
Rain	--	--	--	--	SChc	SChc	Chc	Chc	Chc	Chc	Chc	Chc	Chc	Chc	SChc	--	--	--	--	--	--	--	--	--
Thunder	--	--	--	--	SChc	SChc	Chc	Chc	SChc	SChc	SChc	--	--	--	--	--	--	--	--	--	--	--	--	--
Date							09/12
Hour (EDT)	18	19	20	21	22	23	00	01	02	03	04	05	06	07	08	09	10	11	12	13	14	15	16	17
Temperature (°F)	76	75	73	72	71	70	69	69	68	68	67	67	67	67	68	71	74	77	79	80	81	81	80	79
Dewpoint (°F)	66	66	66	66	66	66	66	66	67	67	67	67	67	67	68	68	69	70	71	72	72	73	73	73
Heat Index (°F)	76	75																77	79	84	85	86	84	79
Surface Wind (mph)	2	1	2	1	1	1	1	1	1	1	2	3	3	3	5	5	6	7	7	7	7	7	7	7
Wind Dir	NE	E	E	E	E	SE	SE	SE	SE	SE	SE	SE	E	E	E	E	SE	SE	SE	SE	SE	SE	SE	SE
Gust
Sky Cover (%)	63	59	54	51	58	59	56	62	57	58	63	68	68	67	68	72	72	74	76	82	83	82	81	82
Precipitation Potential (%)	4	5	3	3	3	3	3	3	14	11	10	12	21	17	11	11	11	11	11	11	60	60	60	60
Relative Humidity (%)	71	74	79	81	84	87	90	90	97	97	100	100	100	100	100	90	84	79	77	77	74	77	79	82
Rain	--	--	--	--	--	--	--	--	--	--	--	--	SChc	SChc	--	--	--	--	--	--	Lkly	Lkly	Lkly	Lkly
Thunder	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	SChc	SChc	SChc	SChc

International System of Units Forecast Discussion 7-Day Forecast Hourly Weather Graph Hazardous Weather Briefing Page Past Weather Information Interactive Forecast Map Home