Point Forecast: Derwood MD  39.12N 77.13W (Elev. 348 ft)	Last Update: 1:30 pm EDT Jul 13, 2025

[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: 7pm Sun, Jul 13 20258pm Sun, Jul 13 20259pm Sun, Jul 13 202510pm Sun, Jul 13 202511pm Sun, Jul 13 202512am Mon, Jul 14 20251am Mon, Jul 14 20252am Mon, Jul 14 20253am Mon, Jul 14 20254am Mon, Jul 14 20255am Mon, Jul 14 20256am Mon, Jul 14 20257am Mon, Jul 14 20258am Mon, Jul 14 20259am Mon, Jul 14 202510am Mon, Jul 14 202511am Mon, Jul 14 202512pm Mon, Jul 14 20251pm Mon, Jul 14 20252pm Mon, Jul 14 20253pm Mon, Jul 14 20254pm Mon, Jul 14 20255pm Mon, Jul 14 20256pm Mon, Jul 14 20257pm Mon, Jul 14 20258pm Mon, Jul 14 20259pm Mon, Jul 14 202510pm Mon, Jul 14 202511pm Mon, Jul 14 202512am Tue, Jul 15 20251am Tue, Jul 15 20252am Tue, Jul 15 20253am Tue, Jul 15 20254am Tue, Jul 15 20255am Tue, Jul 15 20256am Tue, Jul 15 20257am Tue, Jul 15 20258am Tue, Jul 15 20259am Tue, Jul 15 202510am Tue, Jul 15 202511am Tue, Jul 15 202512pm Tue, Jul 15 20251pm Tue, Jul 15 20252pm Tue, Jul 15 20253pm Tue, Jul 15 20254pm Tue, Jul 15 20255pm Tue, Jul 15 20256pm Tue, Jul 15 20257pm Tue, Jul 15 20258pm Tue, Jul 15 20259pm Tue, Jul 15 202510pm Tue, Jul 15 202511pm Tue, Jul 15 202512am Wed, Jul 16 20251am Wed, Jul 16 20252am 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 2025

Date	07/13					07/14
Hour (EDT)	19	20	21	22	23	00	01	02	03	04	05	06	07	08	09	10	11	12	13	14	15	16	17	18
Temperature (°F)	85	82	79	77	76	75	75	74	74	74	73	73	73	75	77	79	81	84	84	85	85	85	83	83
Dewpoint (°F)	75	75	75	74	74	74	74	74	74	73	73	73	73	75	76	76	76	77	77	77	77	77	76	76
Heat Index (°F)	94	89	79	77	76	75	75							75	77	79	87	94	94	96	96	96	91	91
Surface Wind (mph)	5	5	3	3	2	2	2	2	2	2	2	2	2	2	2	2	3	3	5	5	5	3	3	3
Wind Dir	SW	SE	SE	S	S	S	S	S	S	S	S	SE	SE	SE	S	S	S	S	S	S	SE	SE	SE	SE
Gust
Sky Cover (%)	70	53	56	59	61	62	65	68	76	64	65	76	73	72	66	80	65	56	63	80	72	69	78	81
Precipitation Potential (%)	35	30	34	38	42	41	48	33	22	24	24	24	21	15	12	13	19	34	44	56	58	53	66	71
Relative Humidity (%)	72	79	88	90	94	97	97	100	100	97	100	100	100	100	97	91	85	80	80	77	77	77	80	80
Rain	Chc	Chc	Chc	Chc	Chc	Chc	Chc	Chc	SChc	SChc	SChc	SChc	SChc	SChc	--	--	SChc	Chc	Chc	Lkly	Lkly	Chc	Lkly	Lkly
Thunder	Chc	Chc	Chc	Chc	Chc	Chc	Chc	SChc	SChc	SChc	--	--	--	--	--	--	SChc	Chc	Chc	Lkly	Lkly	Chc	Lkly	Lkly
Date						07/15
Hour (EDT)	19	20	21	22	23	00	01	02	03	04	05	06	07	08	09	10	11	12	13	14	15	16	17	18
Temperature (°F)	81	79	77	76	75	74	73	73	73	73	73	73	74	75	77	79	81	83	85	86	86	85	84	83
Dewpoint (°F)	76	75	76	76	75	74	73	73	73	72	72	72	73	74	75	75	76	76	76	76	76	75	75	75
Heat Index (°F)	87	79	77	76	75									75	77	79	87	91	94	96	96	94	92	90
Surface Wind (mph)	2	2	2	2	2	2	1	1	1	1	1	1	2	2	2	2	2	2	3	3	3	3	3	3
Wind Dir	S	N	SE	SE	S	S	S	SW	SW	NW	NW	N	N	N	NE	E	E	SE	SE	S	S	S	S	S
Gust
Sky Cover (%)	87	86	75	76	77	77	78	78	78	79	79	76	74	71	69	67	65	69	74	78	78	78	78	78
Precipitation Potential (%)	80	56	56	56	56	56	56	30	30	30	30	30	30	32	32	32	32	32	32	66	66	66	66	66
Relative Humidity (%)	85	88	97	100	100	100	100	100	100	97	97	97	97	97	94	88	85	80	75	72	72	72	74	77
Rain	Ocnl	Lkly	Lkly	Lkly	Lkly	Lkly	Lkly	Chc	Chc	Chc	Chc	Chc	Chc	Chc	Chc	Chc	Chc	Chc	Chc	Lkly	Lkly	Lkly	Lkly	Lkly
Thunder	Lkly	Chc	Chc	Chc	SChc	SChc	SChc	SChc	SChc	SChc	SChc	SChc	SChc	--	--	--	SChc	SChc	SChc	Chc	Chc	Chc	Chc	Chc

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