Thorold weather in May

In May, Thorold sees average daytime highs of 16°C and overnight lows near 11°C, with 90 mm of rain across 12.2 wet days and about 14.4 hours of daylight. It is the 5th-warmest and 5th-wettest month of the year here.

Highs climb over the month, from about 13°C in the first days to 19°C by the end. The sky is clear or mostly clear about 29% 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 Thorold's 5th-clearest and 9th-windiest month. For the whole year in context, see Thorold's year-round climate.

Daytime high
16°
5th warmest
Overnight low
11°
8th coldest
Rainfall
90 mm
12.2 wet days
Daylight
14 h 30 min
4:59 AM – 7:27 PM
Cloud cover
60%
5th clearest
Wind
16 km/h
9th windiest
Solar energy
5.95 kWh/m²
Travel score
4.8
out of 10

Thorold is city in Niagara Region, Ontario, Canada.

Density
227/km²
people per km²
Founded
1850

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 13°C in the first days to 19°C by the end.

A typical May day in Thorold reaches about 16°C in the afternoon and slips back to 11°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 11°C and 21°C. Set against its neighbours, May runs about 7°C warmer than April and about 6°C cooler than June.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
1137
2138
3138
4138
5148
6149
7149
8149
9159
10159
111510
121510
131610
141610
151611
161611
171611
181711
191711
201712
211712
221812
231812
241813
251813
261913
271913
281914
291914
301914
312014

How May really feels in Thorold

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.

Thorold weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-1° / -6°7712.48.79.20.0
Feb-1° / -6°609.4710.20.0
Mar / -3°7710.94.811.60.0
Apr / 10011.91.813.11.7
May16° / 11°9012.2014.44.8
Jun22° / 17°10312.1015.16.4
Jul25° / 20°10512014.96.7
Aug24° / 20°9010.9013.86.9
Sep21° / 16°9010.3012.36.4
Oct14° / 10°9812.40.110.83.9
Nov / 8511.62.59.51.2
Dec / -1°83126.88.90.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 29% 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 56%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14357
24357
34357
44357
54357
64357
74357
84357
94357
104357
114357
124258
134258
144258
154357
164357
174258
184456
194456
204456
214555
224555
234654
244753
254753
264753
274753
284753
294753
304753
314753

Chance of precipitation in May

Any precipitation

Thorold gets around 90 mm of rain over 12.2 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 39% and peaks near 41% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
140
240
340
440
540
641
741
841
941
1041
1141
1241
1341
1441
1541
1640
1740
1839
1939
2038
2138
2238
2337
2437
2537
2637
2737
2837
2937
3037
3137

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 82% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1973000
2973000
3964000
4955000
5945100
6936100
7936100
8927100
9927100
10908200
11899200
12899200
138810200
148611300
158611300
168412400
178313400
188113510
197914610
207814710
217615720
227515820
237316920
247216930
2569171031
2667181041
2766181141
2864191151
2963191251
3062191261
3160201361

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 16 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
116light breeze
216light breeze
316light breeze
416light breeze
516light breeze
616light breeze
716light breeze
816light breeze
916light 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 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 5:18 AM to 4:47 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)
113.95:187:10
213.95:177:11
314.05:157:12
414.05:147:14
514.05:127:15
614.15:117:16
714.15:107:17
814.25:087:18
914.25:077:19
1014.25:067:20
1114.35:057:22
1214.35:037:23
1314.45:027:24
1414.45:017:25
1514.45:007:26
1614.54:597:27
1714.54:587:28
1814.54:577:29
1914.64:567:30
2014.64:557:31
2114.64:547:32
2214.74:537:33
2314.74:527:34
2414.74:527:35
2514.84:517:36
2614.84:507:37
2714.84:497:38
2814.84:497:39
2914.94:487:40
3014.94:477:41
3114.94:477:42

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.95 kWh/m².

For context, solar energy here swings from a low near 1.27 kWh/m² to a high of 6.37 kWh/m² in June across the year — May's 5.95 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.5Bright
25.5Bright
35.6Bright
45.6Bright
55.6Bright
65.7Bright
75.7Bright
85.7Bright
95.7Bright
105.8Bright
115.8Bright
125.8Bright
135.8Bright
145.8Bright
155.9Bright
165.9Bright
175.9Bright
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
316.3Intense
Planning a trip in May

Is May a good time to visit Thorold?

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

4.8
Sightseeing
5th-best month of the year
1.1
Beach & pool
5th-best month of the year

May is a reasonable time to visit Thorold for sightseeing.

What to pack for Thorold in May

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

In May, Thorold sees daytime highs around 16°C and nights near 11°C. Worth packing: a warm layer, rain gear and sun protection. About 12 days see rain.

a warm layerrain gearsun protection

Sea temperature near Thorold in May

The nearest coast averages about 9°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 28 km away) is warmest in August at about 23°C and coldest in February near 1°C.

It's comfortable for a long swim from Jul 4 to Sep 20 — about 2.6 months when the water holds above 20°C.

0°10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan3Bracing
Feb1Bracing
Mar1Bracing
Apr3Bracing
May9Bracing
Jun17Cool
Jul22Refreshing
Aug23Refreshing
Sep21Refreshing
Oct16Cool
Nov10Bracing
Dec6Bracing

UV index in Thorold 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 Thorold 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 Thorold 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 Thorold is worst in July — around 15 µg/m³ PM2.5 (moderate), about 2.4× the cleanest month (November, 7 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1315 µg/m³Nov 177 µg/m³
PM2.5 (µg/m³)Level
Jan8Good
Feb10Good
Mar12Good
Apr12Moderate
May14Moderate
Jun15Moderate
Jul15Moderate
Aug13Moderate
Sep11Good
Oct7Good
Nov7Good
Dec7Good
Location & terrain

Where is Thorold?

Thorold sits at 43.1°N, 79.2°W, 178 m above sea level, in Canada. The nearest listed city is St. Catharines, 7.0 km away.

Topography around Thorold

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

Within 3 km, the terrain around Thorold has only modest variations in elevation — a maximum elevation change of 85 m around an average of 168 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 193 m; within 80 km, significant variations in elevation — a maximum elevation change of 532 m.

The land around Thorold is covered by trees (29%), artificial surfaces (29%) and grassland (22%) within 3 km, trees (29%), grassland (23%) and cropland (20%) within 16 km, and water (41%) and trees (26%) within 80 km.

3 km
85 m
16 km
193 m
80 km
532 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: St. Catharines 7.0 km · Niagara Falls 11 km · Niagara Falls 12 km · Welland 15 km · Niagara-on-the-Lake 18 km · Grand Island 21 km · Port Colborne 24 km · North Tonawanda 29 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 Thorold (43.1168°, -79.1996°, elevation 178 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).