Cornwall weather in July

In July, Cornwall sees average daytime highs of 26°C and overnight lows near 16°C, with 100 mm of rain across 12.9 wet days and about 15.1 hours of daylight. It is the 1st-warmest and 4th-wettest month of the year here.

Day-to-day highs hold fairly steady near 26°C through the month. The sky is clear or mostly clear about 25% of the time in July, and the air most often feels humid.

Daylight stretches from about 15 h 24 min at the start of July to 14 h 36 min by month's end. Set against the rest of the year, July is Cornwall's 3rd-clearest and 11th-windiest month. For the whole year in context, see Cornwall's year-round climate.

Daytime high
26°
1st warmest
Overnight low
16°
12th coldest
Rainfall
100 mm
12.9 wet days
Daylight
15 h 06 min
4:31 AM – 7:38 PM
Cloud cover
58%
3rd clearest
Wind
10 km/h
11th windiest
Solar energy
5.88 kWh/m²
Travel score
6.2
out of 10

Cornwall is city in Ontario, Canada.

Air quality
Good
PM2.5 6 µg/m³ · 2019
Density
793/km²
people per km²
Founded
1784

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in July

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 26°C through the month.

A typical July day in Cornwall reaches about 26°C in the afternoon and slips back to 16°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 30°C. Set against its neighbours, July runs about 2°C warmer than June and about 1°C warmer than August.

10°15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12615
22615
32615
42615
52615
62616
72616
82616
92616
102616
112616
122616
132616
142616
152616
162616
172616
182616
192616
202616
212616
222616
232616
242616
252616
262616
272616
282616
292616
302616
312616

How July really feels in Cornwall

Once humidity and wind are folded in, July 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

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

Cornwall weather by month

How July compares with the rest of the year at a glance. July is the 1st-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-4° / -12°7311.410.590.0
Feb-2° / -12°61108.710.10.0
Mar / -6°7611.2711.60.2
Apr12° / 10112.12.813.22.8
May19° / 9812.20.114.65.6
Jun24° / 13°10512.4015.46.3
Jul26° / 16°10012.9015.16.2
Aug25° / 15°9411.6013.96.6
Sep21° / 11°9310.5012.36.4
Oct13° / 105120.610.73.6
Nov / -1°8412.43.79.30.6
Dec-0° / -7°8212.49.38.60.0

Cloud cover in July

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

Beyond those clear spells, partly cloudy skies cover about 24% of July, with mostly cloudy or overcast conditions the remaining 51%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14555
24555
34555
44654
54654
64654
74753
84753
94753
104852
114852
124852
134951
144951
154951
165050
175050
185050
195050
205050
215149
225149
235149
245149
255149
265149
275149
285149
295248
305248
315248

Chance of precipitation in July

Any precipitation

Cornwall gets around 100 mm of rain over 12.9 wet days in July. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 43% and peaks near 44% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
143
243
343
443
543
643
743
843
943
1043
1143
1244
1344
1443
1543
1643
1743
1843
1943
2043
2143
2243
2342
2442
2542
2642
2742
2842
2942
3041
3141

Humidity in July

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, July lands in the humid band about 30% of days. Sticky, muggy-or-worse air turns up on roughly 24% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1282924163
2272925163
3262925173
4252925174
5253025174
6243025174
7233025184
8233025184
9222926194
10212926194
11202927204
12202927214
13192828214
14192828214
15182829214
16172730224
17172730224
18172731224
19162632224
20162633224
21162533224
22152534224
23152534224
24152435224
25152536213
26152536213
27152536213
28152536213
29152536212
30152636212
31162635212

Wind in July

Winds average 10 km/h in July.

Across July, daily wind ranges from about 9 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
309calm
319calm

Sunrise & sunset in July

DaylightNight

Daylight runs from about 15 h 24 min at the start of July to 14 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 48 minutes over July. Sunrise moves from 4:21 AM to 4:47 AM, and sunset from 7:44 PM to 7:23 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
115.44:217:44
215.44:217:44
315.44:227:43
415.34:227:43
515.34:237:43
615.34:247:43
715.34:247:42
815.34:257:42
915.34:267:42
1015.24:267:41
1115.24:277:41
1215.24:287:40
1315.24:297:40
1415.24:307:39
1515.14:317:38
1615.14:317:38
1715.14:327:37
1815.04:337:36
1915.04:347:35
2015.04:357:35
2115.04:367:34
2214.94:377:33
2314.94:387:32
2414.94:397:31
2514.84:407:30
2614.84:417:29
2714.84:427:28
2814.74:447:27
2914.74:457:26
3014.64:467:24
3114.64:477:23

Solar energy in July

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in July, about 5.88 kWh/m².

For context, solar energy here swings from a low near 1.2 kWh/m² to a high of 5.91 kWh/m² in June across the year — July's 5.88 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
16.0Intense
26.0Intense
36.0Intense
46.0Intense
56.0Intense
66.0Intense
76.0Bright
86.0Bright
96.0Bright
106.0Bright
116.0Bright
125.9Bright
135.9Bright
145.9Bright
155.9Bright
165.9Bright
175.9Bright
185.8Bright
195.8Bright
205.8Bright
215.8Bright
225.8Bright
235.7Bright
245.7Bright
255.7Bright
265.7Bright
275.6Bright
285.6Bright
295.6Bright
305.6Bright
315.5Bright
Planning a trip in July

Is July a good time to visit Cornwall?

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

6.2
Sightseeing
4th-best month of the year
5.9
Beach & pool
2nd-best month of the year

July is a reasonable time to visit Cornwall for sightseeing.

What to pack for Cornwall in July

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

In July, Cornwall sees daytime highs around 26°C and nights near 16°C. Worth packing: light clothes, rain gear and sun protection. About 13 days see rain.

light clothesrain gearsun protection

UV index in Cornwall in July

LowModerateHighVery highExtreme

Clear-sky midday UV in July peaks around 8 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Cornwall peaks around July 14 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 10 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 highModerateModerateLowJul 14UV 8Jan 10UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr4Moderate
May6High
Jun6High
Jul8Very high
Aug4Moderate
Sep5High
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Cornwall?

Cornwall sits at 45.0°N, 74.7°W, 59 m above sea level, in Canada. The nearest listed city is Les Coteaux, 49 km away.

Topography around Cornwall

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

Within 3 km, the terrain around Cornwall has only modest variations in elevation — a maximum elevation change of 40 m around an average of 58 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 100 m; within 80 km, large variations in elevation — a maximum elevation change of 1,164 m.

The land around Cornwall is covered by trees (35%) and artificial surfaces (26%) within 3 km, trees (51%) within 16 km, and trees (58%) and cropland (28%) within 80 km.

3 km
40 m
16 km
100 m
80 km
1,164 m
treesgrasslandcroplandartificial surfaceswaterwetland
July weather nearby: Les Coteaux 49 km · Salaberry-de-Valleyfield 53 km · Saint-Lazare 63 km · Vaudreuil-Dorion 69 km · Clarence-Rockland 74 km · Orléans 78 km · Fallingbrook 78 km · Gloucester 80 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 Cornwall (45.0181°, -74.7281°, elevation 59 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. 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).