Guelph weather in May

In May, Guelph sees average daytime highs of 18°C and overnight lows near 8°C, with 88 mm of rain across 11.6 wet days and about 14.5 hours of daylight. It is the 5th-warmest and 2nd-wettest month of the year here.

Highs climb over the month, from about 16°C in the first days to 21°C by the end. The sky is clear or mostly clear about 25% 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 15 hours by month's end. Set against the rest of the year, May is Guelph's 5th-clearest and 8th-windiest month. For the whole year in context, see Guelph's year-round climate.

Daytime high
18°
5th warmest
Overnight low
8th coldest
Rainfall
88 mm
11.6 wet days
Daylight
14 h 30 min
5:02 AM – 7:32 PM
Cloud cover
63%
5th clearest
Wind
13 km/h
8th windiest
Solar energy
5.84 kWh/m²
Travel score
5.5
out of 10

Guelph is city in Ontario, Canada.

Air quality
Good
PM2.5 7 µg/m³ · 2019
Density
498/km²
people per km²
Founded
1827

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 16°C in the first days to 21°C by the end.

A typical May day in Guelph reaches about 18°C in the afternoon and slips back to 8°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 11°C and 26°C. Set against its neighbours, May runs about 7°C warmer than April and about 5°C cooler than June.

10°20°30°151015202531
Avg high (°C)Avg low (°C)
1155
2155
3165
4165
5166
6166
7176
8176
9176
10177
11177
12177
13187
14187
15187
16187
17188
18198
19198
20198
21198
22199
23209
24209
25209
262010
272010
282110
292110
302110
312111

How May really feels in Guelph

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.

Guelph weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-2° / -10°6610.89.49.10.0
Feb-1° / -10°538.37.310.20.0
Mar / -5°629.75.611.60.3
Apr12° / 8711.72.513.22.9
May18° / 8811.6014.55.5
Jun23° / 13°9311.6015.26.5
Jul26° / 15°8510.9014.96.7
Aug25° / 15°769.9013.86.9
Sep21° / 10°779.6012.36.5
Oct13° / 78110.410.83.7
Nov / -1°7310.63.69.50.7
Dec / -6°6310.67.98.80.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

Beyond those clear spells, partly cloudy skies cover about 18% of May, with mostly cloudy or overcast conditions the remaining 58%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13862
23961
34060
44060
54060
64060
74159
84060
94060
104159
114258
124258
134258
144357
154258
164258
174258
184258
194357
204357
214456
224456
234456
244456
254456
264555
274555
284555
294555
304555
314456

Chance of precipitation in May

Any precipitation

Guelph gets around 88 mm of rain over 11.6 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 (%)
140
239
339
439
539
639
738
838
938
1038
1138
1238
1337
1437
1537
1637
1737
1837
1937
2037
2136
2236
2336
2436
2536
2636
2736
2836
2936
3036
3136

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 87% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
196310
296310
396310
496310
595410
695410
794420
893520
993520
1092620
1192620
1292620
1392620
1490730
1590730
1690730
1788840
1888840
1986851
2085951
2184961
2283971
2383971
24811081
25791092
26781192
277711102
287612102
297612102
307313113
317313113

Wind in May

Winds average 13 km/h in May.

Across May, daily wind ranges from about 12 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
113light breeze
213light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2012light breeze
2112light breeze
2212light breeze
2312light breeze
2412light breeze
2512light breeze
2612light breeze
2712light breeze
2812light breeze
2912light breeze
3012light breeze
3112light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 54 min at the start of May to 15 hours by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 66 minutes over May. Sunrise moves from 5:21 AM to 4:49 AM, and sunset from 7:15 PM to 7:47 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.95:217:15
213.95:207:16
314.05:187:18
414.05:177:19
514.15:167:20
614.15:147:21
714.25:137:22
814.25:127:23
914.25:107:25
1014.35:097:26
1114.35:087:27
1214.45:077:28
1314.45:057:29
1414.45:047:30
1514.55:037:31
1614.55:027:32
1714.55:017:34
1814.65:007:35
1914.64:597:36
2014.64:587:37
2114.74:577:38
2214.74:567:39
2314.74:557:40
2414.84:547:41
2514.84:547:42
2614.84:537:43
2714.94:527:44
2814.94:517:45
2914.94:517:46
3014.94:507:46
3115.04:497:47

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.84 kWh/m².

For context, solar energy here swings from a low near 1.31 kWh/m² to a high of 6.22 kWh/m² in June across the year — May's 5.84 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.5Bright
25.5Bright
35.5Bright
45.5Bright
55.6Bright
65.6Bright
75.6Bright
85.7Bright
95.7Bright
105.7Bright
115.7Bright
125.8Bright
135.8Bright
145.8Bright
155.8Bright
165.8Bright
175.9Bright
185.9Bright
195.9Bright
205.9Bright
216.0Bright
226.0Bright
236.0Bright
246.0Intense
256.0Intense
266.0Intense
276.0Intense
286.0Intense
296.1Intense
306.1Intense
316.1Intense
Planning a trip in May

Is May a good time to visit Guelph?

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

5.5
Sightseeing
5th-best month of the year
2.0
Beach & pool
5th-best month of the year

May is a reasonable time to visit Guelph for sightseeing.

What to pack for Guelph in May

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

In May, Guelph sees daytime highs around 18°C and nights near 8°C. Worth packing: a warm layer, rain gear and sun protection. About 12 days see rain.

a warm layerrain gearsun protection

Sea temperature near Guelph in May

The nearest coast averages about 8°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 54 km away) is warmest in August at about 21°C and coldest in February near 3°C.

It's comfortable for a long swim from Jul 22 to Sep 1 — about 1.4 months when the water holds above 20°C.

0°10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarm
Sea temperature (°C)Comfort
Jan4Bracing
Feb3Bracing
Mar3Bracing
Apr4Bracing
May8Bracing
Jun15Cool
Jul20Cool
Aug21Refreshing
Sep19Cool
Oct13Bracing
Nov8Bracing
Dec5Bracing

UV index in Guelph 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 Guelph peaks around June 22 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 11 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 22UV 9Jan 11UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr5High
May6High
Jun9Very high
Jul8Very high
Aug7High
Sep5High
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Guelph?

Guelph sits at 43.5°N, 80.3°W, 335 m above sea level, in Canada. The nearest listed city is Hespeler, 13 km away.

Topography around Guelph

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

Within 3 km, the terrain around Guelph has only modest variations in elevation — a maximum elevation change of 73 m around an average of 331 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 143 m; within 80 km, significant variations in elevation — a maximum elevation change of 469 m.

The land around Guelph is covered by trees (42%) and artificial surfaces (42%) within 3 km, trees (38%) and cropland (38%) within 16 km, and cropland (49%) and trees (26%) within 80 km.

3 km
73 m
16 km
143 m
80 km
469 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: Hespeler 13 km · Fiddlesticks 17 km · Fergus 20 km · Cambridge 21 km · Christopher-Champlain 22 km · Waterloo 23 km · Kitchener 25 km · Forest Heights 26 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 Guelph (43.5459°, -80.256°, elevation 335 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).