Osny weather in August

In August, Osny sees average daytime highs of 24°C and overnight lows near 14°C, with 58 mm of rain across 9.2 wet days and about 14.2 hours of daylight. It is the 1st-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 25°C in the first days to 22°C by the end. The sky is clear or mostly clear about 22% of the time in August, and the air most often feels dry.

Daylight stretches from about 15 hours at the start of August to 13 h 18 min by month's end. Set against the rest of the year, August is Osny's 1st-clearest and 12th-windiest month. For the whole year in context, see Osny's year-round climate.

Daytime high
24°
1st warmest
Overnight low
14°
11th coldest
Rainfall
58 mm
9.2 wet days
Daylight
14 h 12 min
5:50 AM – 8:02 PM
Cloud cover
62%
1st clearest
Wind
11 km/h
12th windiest
Solar energy
4.73 kWh/m²
Travel score
7.0
out of 10

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 25°C in the first days to 22°C by the end.

A typical August day in Osny reaches about 24°C in the afternoon and slips back to 14°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 19°C and 29°C. Set against its neighbours, August runs on par with July and about 4°C warmer than September.

10°20°30°151015202531
Avg high (°C)Avg low (°C)
12515
22515
32515
42515
52515
62515
72514
82514
92514
102414
112414
122414
132414
142414
152414
162414
172414
182414
192414
202414
212414
222314
232314
242313
252313
262313
272313
282313
292213
302213
312213

How August really feels in Osny

Once humidity and wind are folded in, August 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

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

Osny weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 5511.30.98.50.8
Feb / 489.81.29.81.2
Mar12° / 5210.50.511.62.9
Apr15° / 51110.113.44.3
May18° / 6411.30155.5
Jun21° / 12°5710.1015.96.4
Jul24° / 14°519.1015.67.0
Aug24° / 14°589.2014.27.0
Sep20° / 11°448.5012.46.4
Oct16° / 6211.2010.54.5
Nov10° / 6011.40.28.92.2
Dec / 7012.60.98.10.9

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 22% of the time in August, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 20% of August, with mostly cloudy or overcast conditions the remaining 58%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14555
24555
34555
44555
54555
64555
74555
84357
94357
104357
114357
124357
134357
144357
154159
164159
174159
184159
194060
204060
214060
224060
234060
243961
253961
263961
273961
283862
293862
303862
313862

Chance of precipitation in August

Any precipitation

Osny gets around 58 mm of rain over 9.2 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 29% and peaks near 31% on the wettest days.

0%10%20%30%40%151015202531
Rain chance (%)
130
230
331
431
531
631
731
831
931
1031
1131
1230
1330
1430
1530
1629
1729
1829
1929
2029
2129
2229
2329
2429
2528
2628
2728
2828
2927
3027
3127

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, August lands in the dry band about 44% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
13642192
23642192
33642192
43742192
53841193
63841183
73941183
83940183
94040183
104040183
114039183
124139182
134139182
144139172
154139172
164239172
174239172
184238172
194338172
204338172
214437172
224536171
234735171
244834161
255033161
265232151
275331151
285431141
295530141
305630131
315729131

Wind in August

Winds average 11 km/h in August, the calmest month.

Across August, daily wind ranges from about 11 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm
3111calm

Sunrise & sunset in August

DaylightNight

Daylight runs from about 15 hours at the start of August to 13 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 102 minutes over August. Sunrise moves from 5:29 AM to 6:12 AM, and sunset from 8:27 PM to 7:32 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
115.05:298:27
214.95:308:26
314.95:318:24
414.85:338:23
514.85:348:21
614.75:358:19
714.75:378:18
814.65:388:16
914.65:408:14
1014.55:418:13
1114.55:428:11
1214.45:448:09
1314.45:458:07
1414.35:478:06
1514.35:488:04
1614.25:508:02
1714.15:518:00
1814.15:537:58
1914.05:547:56
2014.05:567:54
2113.95:577:52
2213.95:587:50
2313.86:007:48
2413.76:017:46
2513.76:037:44
2613.66:047:42
2713.66:067:40
2813.56:077:38
2913.56:097:36
3013.46:107:34
3113.36:127:32

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 4.73 kWh/m².

For context, solar energy here swings from a low near 0.77 kWh/m² to a high of 5.55 kWh/m² in June across the year — August's 4.73 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.2Bright
45.2Bright
55.1Bright
65.1Bright
75.0Bright
85.0Bright
95.0Bright
105.0Bright
114.9Bright
124.9Bright
134.8Bright
144.8Bright
154.8Bright
164.7Bright
174.7Bright
184.7Bright
194.6Bright
204.6Bright
214.5Bright
224.5Bright
234.4Bright
244.4Bright
254.3Bright
264.3Bright
274.3Bright
284.2Bright
294.2Bright
304.1Bright
314.1Bright
Planning a trip in August

Is August a good time to visit Osny?

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

7.0
Sightseeing
1st-best month of the year
5.7
Beach & pool
2nd-best month of the year

August is one of the better times to visit Osny for general sightseeing.

What to pack for Osny in August

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

In August, Osny sees daytime highs around 24°C and nights near 14°C. Worth packing: light clothes, rain gear and sun protection. About 9 days see rain.

light clothesrain gearsun protection

UV index in Osny in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August 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 Osny peaks around June 20 at about 7 (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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowJun 20UV 7Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr5Moderate
May6High
Jun7High
Jul7High
Aug7High
Sep4Moderate
Oct3Moderate
Nov1Low
Dec1Low

Air quality in Osny in August

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Osny is worst in April — around 20 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1020 µg/m³Jul 2014 µg/m³
PM2.5 (µg/m³)Level
Jan17Moderate
Feb17Moderate
Mar20Moderate
Apr20Moderate
May17Moderate
Jun16Moderate
Jul13Moderate
Aug14Moderate
Sep15Moderate
Oct15Moderate
Nov15Moderate
Dec15Moderate
Location & terrain

Where is Osny?

Osny sits at 49.1°N, 2.1°E, 91 m above sea level, in France. The nearest listed city is Pontoise, 4.0 km away.

Topography around Osny

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

Within 3 km, the terrain around Osny has only modest variations in elevation — a maximum elevation change of 83 m around an average of 79 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 217 m; within 80 km, significant variations in elevation — a maximum elevation change of 263 m.

The land around Osny is covered by cropland (33%), trees (32%) and artificial surfaces (25%) within 3 km, trees (39%) and cropland (37%) within 16 km, and cropland (51%) and trees (32%) within 80 km.

3 km
83 m
16 km
217 m
80 km
263 m
treesgrasslandcroplandartificial surfaceswater
August weather nearby: Pontoise 4.0 km · Cergy-Pontoise 4.0 km · Cergy 4.0 km · Vauréal 5.0 km · Saint-Ouen-l'Aumône 5.0 km · Éragny 7.0 km · Jouy-le-Moutier 7.0 km · Conflans-Sainte-Honorine 8.0 km

France travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / E
230 V · 50 Hz
Prices
≈ 77% of US
price level, 2025
GDP per capita
$48,986
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1.3
per 100k, 2023
Road deaths
5.1
per 100k/yr, 2019
Income group
High
World Bank
English
Moderate
EF EPI 539
Religion
Roman Catholic 47%none 33%Muslim 4%Protestant 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 Osny (49.0701°, 2.0628°, elevation 91 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. 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).