Saint John weather in August

In August, Saint John sees average daytime highs of 19°C and overnight lows near 14°C, with 81 mm of rain across 9.3 wet days and about 13.9 hours of daylight. It is the 1st-warmest and 12th-wettest month of the year here.

Day-to-day highs hold fairly steady near 19°C through the month. The sky is clear or mostly clear about 25% of the time in August, and the air most often feels comfortable.

Daylight stretches from about 14 h 36 min at the start of August to 13 h 12 min by month's end. Set against the rest of the year, August is Saint John's 3rd-clearest and 11th-windiest month. For the whole year in context, see Saint John's year-round climate.

Daytime high
19°
1st warmest
Overnight low
14°
12th coldest
Rainfall
81 mm
9.3 wet days
Daylight
13 h 54 min
5:31 AM – 7:26 PM
Cloud cover
64%
3rd clearest
Wind
14 km/h
11th windiest
Solar energy
5.04 kWh/m²
Travel score
6.1
out of 10

Saint John is city in New Brunswick, Canada.

Air quality
Excellent
PM2.5 5 µg/m³ · 2019
Density
227/km²
people per km²
Founded
1604

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 19°C through the month.

A typical August day in Saint John reaches about 19°C in the afternoon and slips back to 14°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 17°C and 21°C. Set against its neighbours, August runs on par with July and about 2°C warmer than September.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
11915
21915
31915
41915
51915
61915
71915
81915
91915
101915
111915
121915
131915
141915
151915
161915
171915
181914
191914
201914
211914
221914
231914
241914
251814
261814
271814
281814
291814
301814
311814

How August really feels in Saint John

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.

Saint John weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-2° / -9°11211.68.48.90.0
Feb-1° / -8°9510.38.210.10.0
Mar / -4°11211.47.211.60.0
Apr / 10512.33.413.20.5
May11° / 10412.30.214.62.4
Jun15° / 11°10812.1015.44.3
Jul18° / 14°9111015.15.6
Aug19° / 14°819.3013.96.1
Sep16° / 12°10810012.35.1
Oct12° / 13310.90.210.73.1
Nov / 12811.82.39.30.8
Dec / -4°13713.16.98.60.0

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 25% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 17% of August, with mostly cloudy or overcast conditions the remaining 59%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13466
23466
33664
43763
53862
63862
73862
83862
93862
103862
113961
123862
133862
143961
154060
164060
174060
184159
194258
204258
214456
224555
234654
244654
254753
264852
274753
284852
294852
304951
314852

Chance of precipitation in August

Any precipitation

Saint John gets around 81 mm of rain over 9.3 wet days in August, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 30% and peaks near 32% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
132
232
332
432
531
632
732
832
932
1032
1132
1232
1332
1432
1531
1631
1731
1830
1930
2029
2129
2228
2328
2428
2528
2628
2728
2828
2928
3028
3129

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the comfortable 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 (%)
12154250
22154250
32056240
42056240
52057230
62057230
72058220
82058220
92058220
102158210
112158210
122158210
132257210
142356210
152356201
162455201
172554201
182654191
192753191
202852191
213051181
223150181
233249171
243448161
253548161
263747151
273946141
284045141
294144131
304343131
314442131

Wind in August

Winds average 14 km/h in August.

Across August, daily wind ranges from about 14 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
114light breeze
214light breeze
314light breeze
414light breeze
514light breeze
614light breeze
714light breeze
814light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1514light breeze
1614light breeze
1714light breeze
1814light breeze
1914light breeze
2014light breeze
2114light breeze
2214light breeze
2314light breeze
2414light breeze
2515light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3015light breeze
3115light breeze

Sunrise & sunset in August

DaylightNight

Daylight runs from about 14 h 36 min at the start of August to 13 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 84 minutes over August. Sunrise moves from 5:13 AM to 5:49 AM, and sunset from 7:48 PM to 6:59 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.65:137:48
214.55:147:47
314.55:157:45
414.55:167:44
514.45:177:43
614.45:187:41
714.35:207:40
814.35:217:38
914.25:227:37
1014.25:237:35
1114.25:257:34
1214.15:267:32
1314.15:277:31
1414.05:287:29
1514.05:297:28
1613.95:317:26
1713.95:327:24
1813.85:337:23
1913.85:347:21
2013.75:367:19
2113.75:377:18
2213.65:387:16
2313.65:397:14
2413.55:417:12
2513.55:427:10
2613.45:437:09
2713.45:447:07
2813.35:467:05
2913.35:477:03
3013.25:487:01
3113.25:496:59

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 5.04 kWh/m².

For context, solar energy here swings from a low near 1.28 kWh/m² to a high of 5.62 kWh/m² in June across the year — August's 5.04 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.3Bright
25.3Bright
35.3Bright
45.3Bright
55.2Bright
65.2Bright
75.2Bright
85.2Bright
95.2Bright
105.2Bright
115.1Bright
125.1Bright
135.1Bright
145.1Bright
155.0Bright
165.0Bright
175.0Bright
185.0Bright
195.0Bright
205.0Bright
214.9Bright
224.9Bright
234.9Bright
244.9Bright
254.8Bright
264.8Bright
274.8Bright
284.8Bright
294.7Bright
304.7Bright
314.6Bright
Planning a trip in August

Is August a good time to visit Saint John?

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
2.4
Beach & pool
1st-best month of the year

August is a reasonable time to visit Saint John for sightseeing.

What to pack for Saint John in August

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

In August, Saint John sees daytime highs around 19°C and nights near 14°C. Worth packing: rain gear and sun protection. About 9 days see rain.

rain gearsun protection

Sea temperature near Saint John in August

The nearest coast averages about 14°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 17 km away) is warmest in August at about 14°C and coldest in March near 2°C.

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

0°5°10°15°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°C)Comfort
Jan5Bracing
Feb3Bracing
Mar2Bracing
Apr3Bracing
May6Bracing
Jun9Bracing
Jul13Bracing
Aug14Bracing
Sep13Bracing
Oct12Bracing
Nov10Bracing
Dec7Bracing

UV index in Saint John 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 Saint John peaks around July 11 at about 7 (very 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 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 11UV 7Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr5Moderate
May7High
Jun7Very high
Jul7Very high
Aug6High
Sep5Moderate
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Saint John?

Saint John sits at 45.3°N, 66.1°W, 30 m above sea level, in Canada. The nearest listed city is Saint John West, 2.0 km away.

Topography around Saint John

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

Within 3 km, the terrain around Saint John has only modest variations in elevation — a maximum elevation change of 95 m around an average of 16 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 234 m; within 80 km, significant variations in elevation — a maximum elevation change of 449 m.

The land around Saint John is covered by water (38%), artificial surfaces (29%) and trees (21%) within 3 km, trees (52%) and water (38%) within 16 km, and trees (49%) and water (45%) within 80 km.

3 km
95 m
16 km
234 m
80 km
449 m
treesgrasslandartificial surfacesbare terrainwaterwetland
August weather nearby: Saint John West 2.0 km · Quispamsis 19 km · Fredericton 89 km · Fredericton Northside 91 km · Riverview 130 km · Lutes Mountain 131 km · Moncton 134 km · Dieppe 139 km

Canada travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 83% of US
price level, 2025
GDP per capita
$55,698
2025
Happiness
6.7 / 10
World Happiness, 2025
Safe drinking water
97%
of population, 2024
Homicide rate
2
per 100k, 2023
Road deaths
5.3
per 100k/yr, 2019
Income group
High
World Bank
Religion
Christian 53%none 35%Muslim 5%Hindu 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 Saint John (45.2708°, -66.0562°, elevation 30 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).