Saint John weather in May

In May, Saint John sees average daytime highs of 11°C and overnight lows near 6°C, with 104 mm of precipitation across 12.3 wet days and about 14.6 hours of daylight. It is the 6th-warmest and 9th-wettest month of the year here.

Highs climb over the month, from about 9°C in the first days to 13°C by the end. The sky is clear or mostly clear about 18% of the time in May, and the air most often feels dry.

Daylight stretches from about 14 hours at the start of May to 15 h 12 min by month's end. Set against the rest of the year, May is Saint John's 11th-clearest and 8th-windiest month. For the whole year in context, see Saint John's year-round climate.

Daytime high
11°
6th warmest
Overnight low
7th coldest
Precipitation
104 mm
12.3 wet days
Daylight
14 h 42 min
5:00 AM – 7:41 PM
Cloud cover
70%
11th clearest
Wind
16 km/h
8th windiest
Solar energy
5.29 kWh/m²
Travel score
2.4
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 May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 9°C in the first days to 13°C by the end.

A typical May day in Saint John reaches about 11°C in the afternoon and slips back to 6°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 8°C and 14°C. Set against its neighbours, May runs about 5°C warmer than April and about 4°C cooler than June.

10°15°20°151015202531
Avg high (°C)Avg low (°C)
194
294
394
494
594
694
795
8105
9105
10105
11105
12105
13106
14116
15116
16116
17116
18116
19117
20127
21127
22127
23127
24127
25128
26128
27138
28138
29138
30138
31138

How May really feels in Saint John

Once humidity and wind are folded in, May averages 0 days that feel above 32°C and 1 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
1
wind chill below the day's low

The story in May is cold — wind chill drags the overnight "feels like" below the raw low.

Saint John weather by month

How May compares with the rest of the year at a glance. May is the 6th-warmest and 9th-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 May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 18% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 15% of May, with mostly cloudy or overcast conditions the remaining 67%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13466
23367
33367
43367
53367
63466
73466
83466
93466
103466
113565
123565
133565
143565
153565
163565
173565
183466
193466
203565
213565
223367
233367
243367
253268
263268
273268
283169
293169
303070
313070

Chance of precipitation in May

Any precipitationSnow

Saint John gets around 104 mm of rain and snow over 12.3 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 40% and peaks near 41% on the wettest days, and about 0 day brings snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
1414
2413
3413
4403
5403
6402
7402
8392
9392
10392
11392
12391
13391
14391
15391
16391
17391
18390
19390
20390
21400
22400
23400
24400
25410
26410
27410
28410
29410
30410
31410

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
11000
21000
31000
41000
51000
61000
71000
81000
91000
101000
111000
121000
131000
141000
151000
161000
171000
181000
191000
201000
211000
221000
231000
241000
251000
261000
271000
281000
291000
30991
31991

Wind in May

Winds average 16 km/h in May.

Across May, daily wind ranges from about 16 km/h on the calmest days to 17 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
117light breeze
217light breeze
317light breeze
417light breeze
517light breeze
617light breeze
717light breeze
817light breeze
917light breeze
1016light breeze
1116light breeze
1216light breeze
1316light breeze
1416light breeze
1516light breeze
1616light breeze
1716light breeze
1816light breeze
1916light breeze
2016light breeze
2116light breeze
2216light breeze
2316light breeze
2416light breeze
2516light breeze
2616light breeze
2716light breeze
2816light breeze
2916light breeze
3016light breeze
3116light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 14 hours at the start of May to 15 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 72 minutes over May. Sunrise moves from 5:21 AM to 4:47 AM, and sunset from 7:22 PM to 7:56 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.05:217:22
214.15:197:23
314.15:187:25
414.25:167:26
514.25:157:27
614.25:137:28
714.35:127:30
814.35:117:31
914.45:097:32
1014.45:087:33
1114.55:077:35
1214.55:057:36
1314.55:047:37
1414.65:037:38
1514.65:027:39
1614.75:007:41
1714.74:597:42
1814.74:587:43
1914.84:577:44
2014.84:567:45
2114.94:557:46
2214.94:547:47
2314.94:537:48
2415.04:527:49
2515.04:517:51
2615.04:517:52
2715.04:507:53
2815.14:497:54
2915.14:487:55
3015.14:487:55
3115.24:477:56

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.29 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 — May's 5.29 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.0Bright
25.1Bright
35.1Bright
45.1Bright
55.1Bright
65.1Bright
75.2Bright
85.2Bright
95.2Bright
105.2Bright
115.2Bright
125.2Bright
135.3Bright
145.3Bright
155.3Bright
165.3Bright
175.3Bright
185.3Bright
195.4Bright
205.4Bright
215.4Bright
225.4Bright
235.4Bright
245.4Bright
255.4Bright
265.4Bright
275.4Bright
285.4Bright
295.4Bright
305.4Bright
315.5Bright
Planning a trip in May

Is May a good time to visit Saint John?

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

2.4
Sightseeing
6th-best month of the year
0.0
Beach & pool
6th-best month of the year

May is a weaker month for outdoor sightseeing in Saint John.

What to pack for Saint John in May

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

In May, Saint John sees daytime highs around 11°C and nights near 6°C. Pack a warm layer. Worth having: rain gear and sun protection. About 12 days see rain.

a warm layerrain gearsun protection

Sea temperature near Saint John in May

The nearest coast averages about 6°C in May — 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 May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 7 — 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
May 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).