Point Forecast: Herndon VA  38.97N 77.38W (Elev. 354 ft)	Last Update: 1:30 am EDT Jul 16, 2025

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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: 2am Wed, Jul 16 20253am Wed, Jul 16 20254am Wed, Jul 16 20255am Wed, Jul 16 20256am Wed, Jul 16 20257am Wed, Jul 16 20258am Wed, Jul 16 20259am Wed, Jul 16 202510am Wed, Jul 16 202511am Wed, Jul 16 202512pm Wed, Jul 16 20251pm Wed, Jul 16 20252pm Wed, Jul 16 20253pm Wed, Jul 16 20254pm Wed, Jul 16 20255pm Wed, Jul 16 20256pm Wed, Jul 16 20257pm Wed, Jul 16 20258pm Wed, Jul 16 20259pm Wed, Jul 16 202510pm Wed, Jul 16 202511pm Wed, Jul 16 202512am Thu, Jul 17 20251am Thu, Jul 17 20252am Thu, Jul 17 20253am Thu, Jul 17 20254am Thu, Jul 17 20255am Thu, Jul 17 20256am Thu, Jul 17 20257am Thu, Jul 17 20258am Thu, Jul 17 20259am Thu, Jul 17 202510am Thu, Jul 17 202511am Thu, Jul 17 202512pm Thu, Jul 17 20251pm Thu, Jul 17 20252pm Thu, Jul 17 20253pm Thu, Jul 17 20254pm Thu, Jul 17 20255pm Thu, Jul 17 20256pm Thu, Jul 17 20257pm Thu, Jul 17 20258pm Thu, Jul 17 20259pm Thu, Jul 17 202510pm Thu, Jul 17 202511pm Thu, Jul 17 202512am Fri, Jul 18 20251am Fri, Jul 18 20252am Fri, Jul 18 20253am Fri, Jul 18 20254am Fri, Jul 18 20255am Fri, Jul 18 20256am Fri, Jul 18 20257am Fri, Jul 18 20258am Fri, Jul 18 20259am Fri, Jul 18 202510am Fri, Jul 18 202511am Fri, Jul 18 202512pm Fri, Jul 18 20251pm Fri, Jul 18 20252pm Fri, Jul 18 20253pm Fri, Jul 18 20254pm Fri, Jul 18 20255pm Fri, Jul 18 20256pm Fri, Jul 18 20257pm Fri, Jul 18 20258pm Fri, Jul 18 20259pm Fri, Jul 18 202510pm Fri, Jul 18 202511pm Fri, Jul 18 202512am Sat, Jul 19 20251am Sat, Jul 19 20252am Sat, Jul 19 20253am Sat, Jul 19 20254am Sat, Jul 19 20255am Sat, Jul 19 20256am Sat, Jul 19 20257am Sat, Jul 19 20258am Sat, Jul 19 20259am Sat, Jul 19 202510am Sat, Jul 19 202511am Sat, Jul 19 202512pm Sat, Jul 19 20251pm Sat, Jul 19 20252pm Sat, Jul 19 20253pm Sat, Jul 19 20254pm Sat, Jul 19 20255pm Sat, Jul 19 20256pm Sat, Jul 19 20257pm Sat, Jul 19 20258pm Sat, Jul 19 20259pm Sat, Jul 19 202510pm Sat, Jul 19 202511pm Sat, Jul 19 202512am Sun, Jul 20 20251am Sun, Jul 20 20252am Sun, Jul 20 20253am Sun, Jul 20 20254am Sun, Jul 20 20255am Sun, Jul 20 20256am Sun, Jul 20 20257am Sun, Jul 20 20258am Sun, Jul 20 20259am Sun, Jul 20 202510am Sun, Jul 20 202511am Sun, Jul 20 202512pm Sun, Jul 20 20251pm Sun, Jul 20 2025

Date	07/16																						07/17
Hour (EDT)	02	03	04	05	06	07	08	09	10	11	12	13	14	15	16	17	18	19	20	21	22	23	00	01
Temperature (°F)	75	75	74	74	74	74	76	79	81	83	86	88	89	87	87	85	83	83	81	78	78	78	77	77
Dewpoint (°F)	74	74	74	73	73	74	75	75	76	76	77	77	77	77	76	76	76	75	75	75	75	75	75	74
Heat Index (°F)	75	75					76	79	87	91	97	100	102	99	98	94	91	90	87	78	78	78	77	77
Surface Wind (mph)	3	3	3	3	3	5	5	5	6	6	7	8	9	9	9	9	8	9	8	8	6	6	6	7
Wind Dir	S	S	S	S	S	S	S	S	S	S	S	S	S	S	SW	SW	S	S	SW	SW	SW	S	SW	SW
Gust
Sky Cover (%)	67	68	64	64	60	61	62	52	57	63	59	60	55	56	73	85	77	74	76	62	65	65	62	56
Precipitation Potential (%)	6	4	5	5	5	5	2	6	3	7	12	16	23	31	42	40	36	60	34	24	14	15	13	7
Relative Humidity (%)	97	97	100	97	97	100	97	88	85	80	75	70	68	72	70	75	80	77	82	91	91	91	94	90
Rain	--	--	--	--	--	--	--	--	--	--	--	SChc	SChc	Chc	Chc	Chc	Chc	Lkly	Chc	SChc	--	SChc	--	--
Thunder	--	--	--	--	--	--	--	--	--	--	--	SChc	SChc	Chc	Chc	Chc	Chc	Lkly	Chc	SChc	--	SChc	--	--
Date																							07/18
Hour (EDT)	02	03	04	05	06	07	08	09	10	11	12	13	14	15	16	17	18	19	20	21	22	23	00	01
Temperature (°F)	76	77	76	75	75	76	78	81	84	87	90	92	93	93	92	91	90	89	87	85	84	82	81	80
Dewpoint (°F)	75	74	74	73	73	74	74	75	75	75	75	74	74	74	74	74	74	74	75	75	75	75	74	74
Heat Index (°F)	76	77	76	75	75	76	78	87	92	96	101	102	103	103	102	101	99	98	96	94	92	89	86	84
Surface Wind (mph)	7	8	8	8	8	8	8	7	8	9	9	9	9	9	9	9	8	8	7	7	6	6	6	5
Wind Dir	SW	SW	SW	SW	SW	SW	SW	SW	SW	SW	SW	SW	SW	SW	SW	SW	SW	SW	SW	SW	W	W	W	W
Gust
Sky Cover (%)	58	36	49	41	22	14	18	37	36	35	41	46	52	52	52	52	52	52	34	40	45	51	49	48
Precipitation Potential (%)	8	10	11	9	7	7	9	9	9	9	9	9	28	28	28	28	28	28	6	6	6	6	6	6
Relative Humidity (%)	97	90	94	94	94	94	88	82	74	68	62	56	54	54	56	58	60	61	68	72	74	79	79	82
Rain	--	--	--	--	--	--	--	--	--	--	--	--	Chc	Chc	Chc	Chc	Chc	Chc	--	--	--	--	--	--
Thunder	--	--	--	--	--	--	--	--	--	--	--	--	SChc	SChc	SChc	Chc	Chc	Chc	--	--	--	--	--	--

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