Niagara-on-the-Lake weather in May

In May, Niagara-on-the-Lake sees average daytime highs of 14°C and overnight lows near 9°C, with 82 mm of rain across 11.5 wet days and about 14.5 hours of daylight. It is the 5th-warmest and 7th-wettest month of the year here.

Highs climb over the month, from about 12°C in the first days to 17°C by the end. The sky is clear or mostly clear about 28% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 54 min at the start of May to 14 h 54 min by month's end. Set against the rest of the year, May is Niagara-on-the-Lake's 5th-clearest and 9th-windiest month. For the whole year in context, see Niagara-on-the-Lake's year-round climate.

Daytime high
14°
5th warmest
Overnight low
7th coldest
Rainfall
82 mm
11.5 wet days
Daylight
14 h 30 min
4:58 AM – 7:27 PM
Cloud cover
61%
5th clearest
Wind
14 km/h
9th windiest
Solar energy
5.96 kWh/m²
Travel score
4.2
out of 10

Niagara-on-the-Lake is town in Niagara Region, Ontario, Canada.

Density
132/km²
people per km²
Founded
1781

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 12°C in the first days to 17°C by the end.

A typical May day in Niagara-on-the-Lake reaches about 14°C in the afternoon and slips back to 9°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 10°C and 19°C. Set against its neighbours, May runs about 6°C warmer than April and about 6°C cooler than June.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
1126
2127
3127
4127
5127
6127
7138
8138
9138
10138
11138
12148
13149
14149
15149
16149
17159
181510
191510
201510
211510
221611
231611
241611
251611
261711
271712
281712
291712
301712
311813

How May really feels in Niagara-on-the-Lake

Once humidity and wind are folded in, May 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

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

Niagara-on-the-Lake weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -5°7713.211.39.20.0
Feb-0° / -6°609.87.810.20.0
Mar / -2°7310.54.911.60.0
Apr / 9611.61.713.21.6
May14° / 8211.5014.54.2
Jun21° / 16°9210.9015.16.3
Jul24° / 20°9210.5014.97.0
Aug24° / 19°7910.2013.87.1
Sep21° / 16°8910012.36.5
Oct14° / 10°9412.70.110.84.0
Nov / 8412.22.69.51.3
Dec / -1°8113.28.48.90.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 28% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 16% of May, with mostly cloudy or overcast conditions the remaining 56%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14456
24456
34456
44456
54456
64357
74357
84357
94159
104159
114159
124159
134159
144159
154258
164258
174258
184357
194357
204357
214357
224555
234555
244654
254654
264753
274753
284753
294654
304654
314654

Chance of precipitation in May

Any precipitation

Niagara-on-the-Lake gets around 82 mm of rain over 11.5 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 37% and peaks near 40% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
138
238
338
439
539
639
739
840
940
1040
1140
1239
1339
1439
1538
1638
1737
1837
1936
2036
2135
2235
2335
2434
2534
2634
2734
2834
2934
3034
3134

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 89% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
199100
299100
399100
498200
598200
698200
798200
897300
997300
1096400
1196400
1295500
1395500
1494600
1593700
1692800
1790910
1890910
19891010
20871120
21851230
22841330
23821440
24791551
25781651
26771661
27751771
28741871
29731881
30711991
31692092

Wind in May

Winds average 14 km/h in May.

Across May, 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
115light breeze
215light breeze
315light breeze
415light breeze
515light breeze
615light breeze
715light 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
2514light breeze
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3014light breeze
3114light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 54 min at the start of May to 14 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 60 minutes over May. Sunrise moves from 5:17 AM to 4:46 AM, and sunset from 7:10 PM to 7:42 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.95:177:10
213.95:167:11
314.05:147:12
414.05:137:13
514.05:127:15
614.15:107:16
714.15:097:17
814.25:087:18
914.25:067:19
1014.35:057:20
1114.35:047:21
1214.35:037:23
1314.45:027:24
1414.45:007:25
1514.44:597:26
1614.54:587:27
1714.54:577:28
1814.54:567:29
1914.64:557:30
2014.64:547:31
2114.74:537:32
2214.74:527:33
2314.74:517:34
2414.74:517:35
2514.84:507:36
2614.84:497:37
2714.84:487:38
2814.94:487:39
2914.94:477:40
3014.94:467:41
3114.94:467:42

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.96 kWh/m².

For context, solar energy here swings from a low near 1.28 kWh/m² to a high of 6.35 kWh/m² in June across the year — May's 5.96 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.5Bright
25.6Bright
35.6Bright
45.6Bright
55.7Bright
65.7Bright
75.7Bright
85.7Bright
95.8Bright
105.8Bright
115.8Bright
125.8Bright
135.8Bright
145.9Bright
155.9Bright
165.9Bright
176.0Bright
186.0Bright
196.0Intense
206.0Intense
216.1Intense
226.1Intense
236.1Intense
246.1Intense
256.2Intense
266.2Intense
276.2Intense
286.2Intense
296.2Intense
306.2Intense
316.2Intense
Planning a trip in May

Is May a good time to visit Niagara-on-the-Lake?

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

4.2
Sightseeing
5th-best month of the year
0.4
Beach & pool
6th-best month of the year

May is a reasonable time to visit Niagara-on-the-Lake for sightseeing.

What to pack for Niagara-on-the-Lake in May

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

In May, Niagara-on-the-Lake sees daytime highs around 14°C and nights near 9°C. Worth packing: a warm layer, rain gear and sun protection. About 12 days see rain.

a warm layerrain gearsun protection

Sea temperature near Niagara-on-the-Lake in May

The nearest coast averages about 7°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 14 km away) is warmest in August at about 22°C and coldest in February near 3°C.

It's comfortable for a long swim from Jul 17 to Sep 6 — about 1.7 months when the water holds above 20°C.

0°10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan4Bracing
Feb3Bracing
Mar3Bracing
Apr4Bracing
May7Bracing
Jun15Bracing
Jul20Refreshing
Aug22Refreshing
Sep19Cool
Oct13Bracing
Nov8Bracing
Dec5Bracing

UV index in Niagara-on-the-Lake in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May 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 Niagara-on-the-Lake peaks around June 19 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 21 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 19UV 8Dec 21UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar4Moderate
Apr5High
May6High
Jun8Very high
Jul7Very high
Aug6High
Sep5High
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Niagara-on-the-Lake in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.

Air quality in Niagara-on-the-Lake is worst in May — around 21 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (November, 10 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodMay 2021 µg/m³Nov 2310 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar17Moderate
Apr18Moderate
May21Moderate
Jun20Moderate
Jul20Moderate
Aug17Moderate
Sep16Moderate
Oct11Good
Nov10Good
Dec10Good
Location & terrain

Where is Niagara-on-the-Lake?

Niagara-on-the-Lake sits at 43.3°N, 79.1°W, 85 m above sea level, in Canada. The nearest listed city is St. Catharines, 16 km away.

Topography around Niagara-on-the-Lake

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Niagara-on-the-Lake.

Within 3 km, the terrain around Niagara-on-the-Lake has only modest variations in elevation — a maximum elevation change of 40 m around an average of 82 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 146 m; within 80 km, significant variations in elevation — a maximum elevation change of 540 m.

The land around Niagara-on-the-Lake is covered by water (47%) within 3 km, water (52%) within 16 km, and water (42%) and trees (24%) within 80 km.

3 km
40 m
16 km
146 m
80 km
540 m
treesgrasslandcroplandartificial surfaceswater
May weather nearby: St. Catharines 16 km · Niagara Falls 17 km · Thorold 18 km · Niagara Falls 18 km · Grand Island 27 km · North Tonawanda 30 km · Welland 33 km · Lockport 33 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 Niagara-on-the-Lake (43.2565°, -79.0853°, elevation 85 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. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).