Portland weather in August

In August, Portland sees average daytime highs of 71°F and overnight lows near 63°F, with 3.2 in of rain across 8.4 wet days and about 13.8 hours of daylight. It is the 2nd-warmest and 11th-wettest month of the year here.

Day-to-day highs hold fairly steady near 71°F through the month. The sky is clear or mostly clear about 37% of the time in August, and the air most often feels humid.

Daylight stretches from about 14 h 24 min at the start of August to 13 h 06 min by month's end. Set against the rest of the year, August is Portland's 2nd-clearest and 12th-windiest month. For the whole year in context, see Portland's year-round climate.

Daytime high
71°
2nd warmest
Overnight low
63°
11th coldest
Rainfall
3.2 in
8.4 wet days
Daylight
13 h 48 min
4:51 AM – 6:40 PM
Cloud cover
54%
2nd clearest
Wind
8 mph
12th windiest
Solar energy
5.37 kWh/m²
Travel score
6.9
out of 10

Portland is seat of Cumberland County, and largest city in State of Maine, United States.

Density
372/km²
people per km²
Founded
1632

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

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 71°F through the month.

A typical August day in Portland reaches about 71°F in the afternoon and slips back to 63°F overnight — a 8°F spread between the day's warmth and the night's chill. On most days the high lands between 66°F and 76°F. Set against its neighbours, August runs on par with July and about 6°F warmer than September.

50°60°70°80°151015202531
Avg high (°F)Avg low (°F)
17264
27264
37264
47264
57264
67264
77264
87264
97264
107164
117164
127164
137163
147163
157163
167163
177163
187163
197163
207163
217163
227162
237062
247062
257062
267062
277062
287062
296961
306961
316961

How August really feels in Portland

Once humidity and wind are folded in, August averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
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.

Portland weather by month

How August compares with the rest of the year at a glance. August is the 2nd-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan32° / 20°3.99.96.99.10.0
Feb33° / 21°3.68.96.510.20.0
Mar38° / 28°4.610.95.611.60.0
Apr47° / 38°4.710.71.913.21.6
May56° / 47°3.9110.114.53.7
Jun65° / 56°4.010.3015.25.7
Jul71° / 63°3.19.2014.96.7
Aug71° / 63°3.28.4013.86.9
Sep65° / 57°3.78.7012.36.2
Oct56° / 47°5.410.60.210.83.8
Nov46° / 37°4.510.41.49.51.3
Dec37° / 28°4.9115.88.80.0

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 37% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 20% of August, with mostly cloudy or overcast conditions the remaining 43%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15248
25347
35347
45446
55446
65446
75446
85446
95446
105446
115446
125446
135446
145545
155545
165545
175644
185644
195743
205842
215941
226040
236040
246139
256139
266139
276139
286139
296139
306040
316040

Chance of precipitation in August

Any precipitation

Portland gets around 3.2 in of rain over 8.4 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 27% and peaks near 29% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
128
228
327
427
527
627
728
828
928
1028
1129
1229
1329
1429
1529
1629
1729
1828
1928
2027
2127
2226
2326
2426
2525
2625
2725
2825
2925
3025
3125

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the humid band about 41% of days. Sticky, muggy-or-worse air turns up on roughly 15% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
16284421
26294420
36294420
47294420
57304420
67304419
77304419
87304419
98304418
108304418
118304417
129304417
139304416
1410304416
1510314416
1611314315
1711314315
1812314314
1912324213
2013324213
2114334112
2215334012
2316343911
2417343811
2519353610
2620353510
2721363410
282236339
292336329
302536319
312636308

Wind in August

Winds average 8 mph in August, the calmest month.

Across August, daily wind ranges from about 8 mph on the calmest days to 8 mph at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (mph)Feels
18light breeze
28light breeze
38light breeze
48light breeze
58light breeze
68light breeze
78light breeze
88light breeze
98light breeze
108light breeze
118light breeze
128light breeze
138light breeze
148light breeze
158light breeze
168light breeze
178light breeze
188light breeze
198light breeze
208light breeze
218light breeze
228light breeze
238light breeze
248light breeze
258light breeze
268light breeze
278light breeze
288light breeze
298light breeze
308light breeze
318light breeze

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 24 min at the start of August to 13 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 78 minutes over August. Sunrise moves from 4:34 AM to 5:08 AM, and sunset from 7:00 PM to 6:14 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.44:347:00
214.44:356:59
314.44:366:58
414.34:376:57
514.34:386:55
614.24:396:54
714.24:406:53
814.24:426:51
914.14:436:50
1014.14:446:49
1114.04:456:47
1214.04:466:46
1313.94:476:44
1413.94:486:43
1513.94:506:41
1613.84:516:40
1713.84:526:38
1813.74:536:36
1913.74:546:35
2013.64:556:33
2113.64:566:32
2213.54:586:30
2313.54:596:28
2413.45:006:26
2513.45:016:25
2613.35:026:23
2713.35:036:21
2813.25:056:20
2913.25:066:18
3013.25:076:16
3113.15:086:14

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.37 kWh/m².

For context, solar energy here swings from a low near 1.46 kWh/m² to a high of 6.02 kWh/m² in July across the year — August's 5.37 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.7Bright
25.7Bright
35.7Bright
45.6Bright
55.6Bright
65.6Bright
75.6Bright
85.5Bright
95.5Bright
105.5Bright
115.4Bright
125.4Bright
135.4Bright
145.4Bright
155.3Bright
165.3Bright
175.3Bright
185.3Bright
195.3Bright
205.3Bright
215.3Bright
225.2Bright
235.2Bright
245.2Bright
255.2Bright
265.1Bright
275.1Bright
285.1Bright
295.0Bright
305.0Bright
315.0Bright
Planning a trip in August

Hazard calendar for Portland

In seasonPeak

In August, Portland sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.

Portland sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is August a good time to visit Portland?

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

6.9
Sightseeing
1st-best month of the year
4.5
Beach & pool
1st-best month of the year

August is a reasonable time to visit Portland for sightseeing.

What to pack for Portland in August

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

In August, Portland sees daytime highs around 71°F and nights near 63°F. Worth packing: rain gear and sun protection. About 8 days see rain.

rain gearsun protection

Sea temperature near Portland in August

The nearest coast averages about 63°F in August — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in August at about 63°F and coldest in March near 38°F.

The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.

40°50°60°70°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°F)Comfort
Jan42Bracing
Feb39Bracing
Mar38Bracing
Apr42Bracing
May48Bracing
Jun55Bracing
Jul62Cool
Aug63Cool
Sep60Cool
Oct54Bracing
Nov49Bracing
Dec45Bracing

UV index in Portland in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Portland peaks around July 12 at about 7 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 23 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateModerateLowJul 12UV 7Dec 23UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar4Moderate
Apr5Moderate
May7High
Jun7High
Jul7Very high
Aug4Moderate
Sep6High
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Portland?

Portland sits at 43.7°N, 70.3°W, 62 ft above sea level, in United States. The nearest listed city is South Portland, 1.2 mi away.

Topography around Portland

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Portland.

Within 2 miles, the terrain around Portland has only modest variations in elevation — a maximum elevation change of 180 ft around an average of 30 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 548 ft; within 50 miles, large variations in elevation — a maximum elevation change of 2,352 ft.

The land around Portland is covered by water (40%), artificial surfaces (31%) and trees (21%) within 2 miles, trees (43%) and water (39%) within 10 miles, and trees (61%) and water (33%) within 50 miles.

2 miles
180 ft
10 miles
548 ft
50 miles
2,352 ft
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
August weather nearby: South Portland 1.2 mi · South Portland Gardens 3.1 mi · Westbrook 5.6 mi · West Scarborough 8.7 mi · Saco 14 mi · Biddeford 15 mi · Brunswick 23 mi · Sanford 30 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 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 Portland (43.6574°, -70.2589°, elevation 62 ft), 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). 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).