Boston weather in August

In August, Boston sees average daytime highs of 21°C and overnight lows near 13°C, with 63 mm of rain across 10.9 wet days and about 14.5 hours of daylight. It is the 2nd-warmest and 1st-wettest month of the year here.

Highs ease over the month, from about 21°C in the first days to 20°C by the end. The sky is clear or mostly clear about 13% of the time in August, and the air most often feels dry.

Daylight stretches from about 15 h 30 min at the start of August to 13 h 30 min by month's end. Set against the rest of the year, August is Boston's 1st-clearest and 11th-windiest month. For the whole year in context, see Boston's year-round climate.

Daytime high
21°
2nd warmest
Overnight low
13°
12th coldest
Rainfall
63 mm
10.9 wet days
Daylight
14 h 30 min
4:48 AM – 7:21 PM
Cloud cover
69%
1st clearest
Wind
15 km/h
11th windiest
Solar energy
4.09 kWh/m²
Travel score
6.1
out of 10

Boston is town and port in Lincolnshire, England, UK.

Density
2,461/km²
people per km²

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 21°C in the first days to 20°C by the end.

A typical August day in Boston reaches about 21°C in the afternoon and slips back to 13°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 17°C and 24°C. Set against its neighbours, August runs on par with July and about 3°C warmer than September.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12114
22114
32114
42114
52114
62114
72114
82114
92114
102114
112114
122114
132114
142114
152114
162114
172113
182113
192113
202113
212013
222013
232013
242013
252013
262013
272013
282013
292013
302012
311912

How August really feels in Boston

Once humidity and wind are folded in, August averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

August sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Boston weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 4911.30.87.90.9
Feb / 389.11.19.51.1
Mar10° / 4210.10.611.52.1
Apr12° / 4610.50.113.63.3
May15° / 5010015.54.6
Jun18° / 11°6111.1016.65.5
Jul21° / 13°6211.1016.26.1
Aug21° / 13°6310.9014.56.1
Sep18° / 11°559.5012.45.6
Oct14° / 6010.6010.33.9
Nov10° / 5511.10.28.42.1
Dec / 51110.97.41.0

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 13% of the time in August, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 22% of August, with mostly cloudy or overcast conditions the remaining 66%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13664
23664
33664
43565
53565
63565
73565
83664
93664
103763
113763
123763
133763
143664
153664
163664
173664
183466
193466
203466
213466
223367
233367
243367
253466
263268
273268
283268
293268
303268
313367

Chance of precipitation in August

Any precipitation

Boston gets around 63 mm of rain over 10.9 wet days in August, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 35% and peaks near 37% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
136
236
336
435
535
635
735
835
934
1035
1135
1235
1335
1436
1536
1636
1737
1837
1937
2037
2137
2237
2336
2436
2535
2634
2734
2833
2932
3032
3131

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

Most of August feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, August lands in the dry band about 53% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
14440161
24440161
34440161
44439151
54539151
64539151
74638151
84738151
94837151
104836151
114936151
125035141
135035141
145134141
155134141
165134141
175333131
185333131
195433130
205632120
215632120
225831110
235931100
246030100
25613090
26623080
27623080
28642970
29652960
30652960
31662950

Wind in August

Winds average 15 km/h in August.

Across August, daily wind ranges from about 15 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
115light breeze
215light breeze
315light breeze
415light breeze
515light breeze
615light breeze
715light breeze
815light breeze
915light breeze
1015light breeze
1115light breeze
1215light breeze
1315light breeze
1415light breeze
1515light breeze
1615light breeze
1715light breeze
1815light breeze
1915light breeze
2015light breeze
2115light breeze
2215light breeze
2315light breeze
2415light breeze
2515light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3015light breeze
3115light breeze

Sunrise & sunset in August

DaylightNight

Daylight runs from about 15 h 30 min at the start of August to 13 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 120 minutes over August. Sunrise moves from 4:23 AM to 5:14 AM, and sunset from 7:50 PM to 6:46 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
115.54:237:50
215.44:247:48
315.34:267:46
415.34:277:44
515.24:297:43
615.24:317:41
715.14:327:39
815.04:347:37
915.04:367:35
1014.94:387:33
1114.94:397:31
1214.84:417:29
1314.74:437:27
1414.74:447:25
1514.64:467:23
1614.54:487:21
1714.54:507:18
1814.44:517:16
1914.44:537:14
2014.34:557:12
2114.24:577:10
2214.24:587:07
2314.15:007:05
2414.05:027:03
2513.95:047:00
2613.95:056:58
2713.85:076:56
2813.75:096:53
2913.75:116:51
3013.65:126:49
3113.55:146:46

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.09 kWh/m².

For context, solar energy here swings from a low near 0.57 kWh/m² to a high of 5.02 kWh/m² in June across the year — August's 4.09 kWh/m² falls in the middle.

024151015202531
Solar energy (kWh/m²)Level
14.6Bright
24.6Bright
34.5Bright
44.5Bright
54.5Bright
64.4Bright
74.4Bright
84.4Bright
94.3Bright
104.3Bright
114.3Bright
124.3Bright
134.2Bright
144.2Bright
154.2Bright
164.1Bright
174.1Bright
184.0Bright
194.0Bright
204.0Moderate
213.9Moderate
223.9Moderate
233.8Moderate
243.8Moderate
253.8Moderate
263.7Moderate
273.7Moderate
283.6Moderate
293.6Moderate
303.5Moderate
313.5Moderate
Planning a trip in August

Is August a good time to visit Boston?

Our two travel scores rate August for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

6.1
Sightseeing
1st-best month of the year
3.6
Beach & pool
2nd-best month of the year

August is a reasonable time to visit Boston for sightseeing.

What to pack for Boston in August

From August's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In August, Boston sees daytime highs around 21°C and nights near 13°C. Worth packing: rain gear. About 11 days see rain.

rain gear

Sea temperature near Boston in August

The nearest coast averages about 18°C in August — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 29 km away) is warmest in August at about 18°C and coldest in February near 5°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

5°10°15°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°C)Comfort
Jan6Bracing
Feb5Bracing
Mar6Bracing
Apr8Bracing
May11Bracing
Jun14Bracing
Jul17Cool
Aug18Cool
Sep16Cool
Oct13Bracing
Nov10Bracing
Dec7Bracing

UV index in Boston in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Boston peaks around August 11 at about 6 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 1 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 6 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowAug 11UV 6Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb1Low
Mar3Moderate
Apr3Moderate
May6High
Jun6High
Jul6High
Aug6High
Sep4Moderate
Oct2Low
Nov1Low
Dec1Low
Location & terrain

Where is Boston?

Boston sits at 53.0°N, 0.0°W, 9 m above sea level, in United Kingdom. The nearest listed city is Spalding, 23 km away.

Topography around Boston

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Boston.

Within 3 km, the terrain around Boston has only modest variations in elevation — a maximum elevation change of 21 m around an average of 2 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 23 m; within 80 km, only modest variations in elevation — a maximum elevation change of 249 m.

The land around Boston is covered by cropland (38%), artificial surfaces (26%) and grassland (23%) within 3 km, cropland (68%) within 16 km, and cropland (54%) within 80 km.

3 km
21 m
16 km
23 m
80 km
249 m
treesgrasslandcroplandartificial surfaceswaterwetland
August weather nearby: Spalding 23 km · Sleaford 26 km · Skegness 31 km · Wisbech 37 km · King's Lynn 38 km · Grantham 42 km · Louth 43 km · Lincoln 44 km

United Kingdom travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type D / G / M
230 V · 50 Hz
Prices
≈ 89% of US
price level, 2025
GDP per capita
$57,602
2025
Happiness
6.7 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1.1
per 100k, 2021
Road deaths
3.2
per 100k/yr, 2019
Income group
High
World Bank
Religion
Christian 60%none 26%Muslim 4%other 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Boston (52.9763°, -0.0266°, elevation 9 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).