Point Forecast: Acton MA  42.48N 71.43W (Elev. 63 m)	Last Update: 6:42 am EDT May 21, 2026

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Weather Elements Fire Weather Aviation Weather Temperature (°C) Dewpoint (°C) Heat Index (°C) Surface Wind  ktmphkm/hm/s Sky Cover (%) Precipitation Potential (%) Relative Humidity (%) Rain Thunder Fog Mixing Height  x100ftx100m Trans. Wind  ktmphkm/hm/s 20ft Wind  ktmphkm/hm/s Vent Rate (x1000 mph-m) Dispersion Index Ceiling Height Visibility Thunder Potential

48-Hour Period Starting: 5pm Thu, May 21 20266pm Thu, May 21 20267pm Thu, May 21 20268pm Thu, May 21 20269pm Thu, May 21 202610pm Thu, May 21 202611pm Thu, May 21 202612am Fri, May 22 20261am Fri, May 22 20262am Fri, May 22 20263am Fri, May 22 20264am Fri, May 22 20265am Fri, May 22 20266am Fri, May 22 20267am Fri, May 22 20268am Fri, May 22 20269am Fri, May 22 202610am Fri, May 22 202611am Fri, May 22 202612pm Fri, May 22 20261pm Fri, May 22 20262pm Fri, May 22 20263pm Fri, May 22 20264pm Fri, May 22 20265pm Fri, May 22 20266pm Fri, May 22 20267pm Fri, May 22 20268pm Fri, May 22 20269pm Fri, May 22 202610pm Fri, May 22 202611pm Fri, May 22 202612am Sat, May 23 20261am Sat, May 23 20262am Sat, May 23 20263am Sat, May 23 20264am Sat, May 23 20265am Sat, May 23 20266am Sat, May 23 20267am Sat, May 23 20268am Sat, May 23 20269am Sat, May 23 202610am Sat, May 23 202611am Sat, May 23 202612pm Sat, May 23 20261pm Sat, May 23 20262pm Sat, May 23 20263pm Sat, May 23 20264pm Sat, May 23 20265pm Sat, May 23 20266pm Sat, May 23 20267pm Sat, May 23 20268pm Sat, May 23 20269pm Sat, May 23 202610pm Sat, May 23 202611pm Sat, May 23 202612am Sun, May 24 20261am Sun, May 24 20262am Sun, May 24 20263am Sun, May 24 20264am Sun, May 24 20265am Sun, May 24 20266am Sun, May 24 20267am Sun, May 24 20268am Sun, May 24 20269am Sun, May 24 202610am Sun, May 24 202611am Sun, May 24 202612pm Sun, May 24 20261pm Sun, May 24 20262pm Sun, May 24 20263pm Sun, May 24 20264pm Sun, May 24 20265pm Sun, May 24 20266pm Sun, May 24 20267pm Sun, May 24 20268pm Sun, May 24 20269pm Sun, May 24 202610pm Sun, May 24 202611pm Sun, May 24 202612am Mon, May 25 20261am Mon, May 25 20262am Mon, May 25 20263am Mon, May 25 20264am Mon, May 25 20265am Mon, May 25 20266am Mon, May 25 20267am Mon, May 25 20268am Mon, May 25 20269am Mon, May 25 202610am Mon, May 25 202611am Mon, May 25 202612pm Mon, May 25 20261pm Mon, May 25 20262pm Mon, May 25 20263pm Mon, May 25 20264pm Mon, May 25 20265pm Mon, May 25 20266pm Mon, May 25 20267pm Mon, May 25 20268pm Mon, May 25 20269pm Mon, May 25 202610pm Mon, May 25 202611pm Mon, May 25 202612am Tue, May 26 20261am Tue, May 26 20262am Tue, May 26 20263am Tue, May 26 20264am Tue, May 26 2026

Date	05/21							05/22
Hour (EDT)	17	18	19	20	21	22	23	00	01	02	03	04	05	06	07	08	09	10	11	12	13	14	15	16
Temperature (°C)	19	18	17	15	12	11	10	9	8	7	6	5	4	5	7	9	12	13	15	17	18	19	19	19
Dewpoint (°C)	2	2	3	3	3	3	3	3	2	2	2	2	2	2	2	2	1	1	1	1	1	1	1	1
Heat Index (°C)
Surface Wind (mph)	5	5	3	3	3	3	3	3	3	3	3	3	3	3	3	5	5	5	5	5	3	3	5	5
Wind Dir	NW	N	N	N	N	N	N	N	N	N	N	N	N	N	NE	NE	NE	NE	NE	E	E	E	E	SE
Gust
Sky Cover (%)	81	81	81	81	79	76	74	68	63	58	47	38	28	23	18	13	16	18	21	30	40	49	55	60
Precipitation Potential (%)	6	5	4	3	2	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Relative Humidity (%)	33	35	39	45	52	56	61	65	68	70	73	79	82	79	70	61	48	45	39	34	31	30	30	29
Rain	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--
Thunder	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--
Date								05/23
Hour (EDT)	17	18	19	20	21	22	23	00	01	02	03	04	05	06	07	08	09	10	11	12	13	14	15	16
Temperature (°C)	19	18	17	15	13	12	11	11	10	9	9	8	8	9	10	12	13	15	16	17	17	17	17	17
Dewpoint (°C)	1	1	2	2	2	2	3	3	3	3	3	3	3	4	4	4	4	4	4	4	3	3	3	4
Heat Index (°C)
Surface Wind (mph)	6	5	5	3	3	2	1	1	0	0	0	0	0	0	0	1	2	3	5	6	7	7	7	7
Wind Dir	SE	SE	SE	SE	SE	S	S	S	SW	SW	W	NW	NW	N	N	NE	NE	E	E	E	E	E	E	SE
Gust
Sky Cover (%)	65	65	65	64	60	59	58	64	69	75	74	73	72	76	80	84	85	85	86	87	88	89	89	89
Precipitation Potential (%)	0	0	0	0	0	0	0	0	0	2	2	2	2	2	2	2	2	2	2	2	3	3	4	4
Relative Humidity (%)	30	31	35	42	49	52	56	59	63	66	68	71	71	71	66	61	55	47	44	41	39	39	39	43
Rain	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--
Thunder	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--	--

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