5-day weather forecast Boston 21-04-2026

Weather forecast Boston tomorrow 21.04.2026: sunny, temperature from 1 °C to 9 °C.

No precipitation expected. Wind up to 5.5 m/s (gusts 7.69 m/s). Air humidity 26–71%, atmospheric pressure 767–771 mm Hg, UV index up to 5.7.

Sunrise 05:54
Sunset 19:33

Waxing Crescent17% illuminated
Moonrise 08:37 · Moonset 00:07

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Table

← Mon, Apr 20

Tue, Apr 21, 2026

Wed, Apr 22 →

Forecast from 1 °C to 9 °C and precipitation

Temperature & Precipitation
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
Temperature (°C)	3	3	3	2	2	1	2	2	4	5	6	7	8	8	9	9	9	8	7	7	6	5	5	5
Precipitation (mm/hr)	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

Cloud cover and precipitation probability

Cloud cover & Rain chance
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
Cloud cover (%)	96	44	31	18	9	6	4	3	0	10	7	14	36	14	11	7	8	13	17	22	37	39	89	44
Rain chance (%)	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

Wind speed and direction

Wind & Wind gust
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
Wind (m/s)	3.61	3.39	3.31	3.39	3.19	3	2.81	2.81	2.69	2.19	1.69	1.19	1.31	1.5	2	2.81	3.89	4.39	4.61	4.89	5.31	5.5	5.19	5
Wind gust (m/s)	4.97	4.78	4.64	4.89	4.72	4.47	4.22	3.75	3.19	2.53	1.97	1.39	1.5	1.72	2.31	3.22	4.5	5.06	5.39	6.56	7.47	7.69	7.33	7.08
Wind direction (°)	N 7°	N 3°	N 359°	N 357°	N 356°	N 351°	N 351°	N 352°	N 0°	N 10°	NNE 29°	NE 44°	E 84°	E 91°	ESE 102°	ESE 111°	ESE 117°	SE 125°	SE 131°	SE 142°	SSE 155°	S 176°	S 186°	SSW 195°

Air humidity

Humidity
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
Humidity (%)	71	45	46	51	54	55	56	52	46	40	33	30	28	27	26	27	31	34	40	46	49	48	50	53

Atmospheric pressure

Pressure
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
Pressure (mm Hg)	769	770	770	770	770	770	770	771	771	771	771	771	770	770	769	768	768	767	768	768	768	768	768	768

Ultraviolet index

UV Index
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
UV Index	0	0	0	0	0	0	0	0.2	0.8	1.8	3.1	4.5	5.5	5.7	5.1	3.9	2.5	1.3	0.5	0.1	0	0	0	0

Air quality & pollen

Air quality
Time	00:00	01:00	02:00	03:00	04:00	05:00	06:00	07:00	08:00	09:00	10:00	11:00	12:00	13:00	14:00	15:00	16:00	17:00	18:00	19:00	20:00	21:00	22:00	23:00
PM2.5 (µg/m³)	7.3	7.7	8.5	10.2	9.9	7.6	7	6.8	6.4	6	6.3	6.2	6.1	6.1	6.4	8.4	10.2	10.1	10.3	11.1	11.4	10.4	9.3	8.7
PM10 (µg/m³)	7.8	8.3	9	10.7	10.6	8.4	7.8	7.6	7.2	6.8	7.1	6.9	6.9	6.9	7.2	9.1	10.8	10.6	10.7	11.4	11.9	10.9	9.8	9.5
Ozone (O₃) (µg/m³)	72	68	66	64	66	73	82	90	94	96	97	99	100	98	89	77	68	65	66	68	71	76	79	81
NO₂ (µg/m³)	10.2	11.5	12.9	14.4	14.7	12.8	9.8	7.7	7.4	8	8.7	8.5	8.3	10	15.6	22.9	27.7	27.6	24.9	21.8	18.5	14.8	11.9	10.1
SO₂ (µg/m³)	3.3	3.6	4	4.5	4.7	4.5	4.1	3.7	3.6	3.5	3.5	3.4	3.4	3.4	3.5	3.7	3.8	3.9	4	4	3.8	3.6	3.4	3.4
CO (µg/m³)	177.9	180.9	187.9	197.9	203.9	201.9	194.9	188.9	185.9	182.9	181.9	180.9	180.9	184.9	195.9	211.9	221.9	223.9	220.9	216.9	211.9	206.9	201.9	196.9

← Mon, Apr 20

Tue, Apr 21, 2026

Wed, Apr 22 →

Boston on the map

Data Sources & Methodology

Our weather forecasts are powered by a professional weather data provider that aggregates data from national weather services, satellite observations, radar networks, and over 80,000 weather stations worldwide. Forecast data is updated multiple times daily. We convert raw data into clear summaries — wind speed in m/s, pressure in mmHg — so you can plan your day with confidence.

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